Hoa hoc 11 full tailieuonthi.vn.pdf

LI NI U

Ngy nay, gio dc l cha kha dn ti thnh cng ca mt quc gia. Gio dc l mt qu trnh rn luyn nhm nng cao nng lc ca ngi hc, bi vy t hc ng vai tr rt quan trng. Qu trnh t hc gip h thng ha, chnh xc ha kin thc, rn luyn k nng, gip cho ngi hc c mt nn tng vng chc khng nhng ni dung kin thc, k nng m quan trng hn l phng php t hc, lm c s cho vic hc tp, nghin cu trnh cao hn hay vn dng vo i sng thc tin.

Trong qu trnh t hc mn Ha hc vic s dng h thng bi tp ha hc phong ph, a dng v ni dung v hnh thc l rt cn thit. c thm mt ti liu tham kho phc v i mi phng php dy hc theo hng tng cng t hc, chng ti bin son cun sch "Hng dn t hc ha hc 11 ". Sch gm 9 chng, tng ng vi tng chng trong sch gio khoa ha hc 11. Trong mi chng c phn n tp cc kin thc c bn ca chng, phn dng bi tp v phng php gii. Cc bi tp bao gm c hnh thc trc nghim t lun v trc nghim khch quan, c mt s cu trch trong cc thi tuyn sinh i hc, Cao ng gn y vi cc hng dn d hiu. Sau mi chng c gii thiu mt s t kim tra c phn p n v hng dn gii mt s cu hi, do s thun tin cho cc em hc sinh yu thch ha hc c th t c, t hc thng qua cun sch ny. Sch do tp th cc Thy, c khoa Ha hc - trng i hc s phm H ni bin son, trong PGS.TS Trn Trung Ninh l ch bin v bin son cc chng 4, 5 v 7, c Phm Th Kim Ngn bin son chng 6, 8, 9, c Bi Hng Giang bin son chng 1, 2, 3.

Xin trn trng gii thiu vi cc thy c gio v cc em hc sinh cun sch "Hng dn t hc ha hc 11". Cc tc gi c nhiu c gng, nhng chc chn khng trnh khi thiu st. Chng ti xin chn thnh cm n cc kin ng gp qu bu ca cc bn c sch c th hon chnh hn trong ln ti bn sau, nu c.

Cc tc gi

Bui Duc Thanh - 0984.586.179 - http://tailieuonthi.vn

CHNG 1. S IN LI 1. S IN LI. PHN LOI CC CHT IN LI A. Tm tt l thuyt I. S IN LI

1. nh ngha:

- S in li: l qu trnh phn li cc cht trong nc ra ion.

- Cht in li: l nhng cht tan trong nc phn li ra ion. Do dung dch cht in li dn in c.

V d: NaCl l cht in li; cn ng saccaroz khng phi l cht in li mc d n tan c trong nc nhng khng phn li ra cc ion.

2. in li () v cht in li mnh, yu - in li (anpha) ca cht in li l t s phn t phn li ra ion (n) v tng s phn t ho tan (n0).

= on

n; 0 < 1, nu tnh theo phn trm th 0% < 100%

Th d, trong dung dch CH3COOH 0,043M, c 100 phn t CH3COOH ho tan th

ch c 2 phn t phn li ra ion, in li l: = 100

2 = 0,02 hay 2%.

- Nu = 0, qu trnh in li khng xy ra, l cht khng in li.

- Nu = 1, l cht in li mnh, khi tan trong nc cc phn t ho tan u phn li ra ion. V d:

+ Cc axit mnh nh HCl, HNO3

, HBr, H2SO4, HClO4 ,...

+ Cc baz mnh nh NaOH, KOH, Ba(OH)2 , Ca(OH)2... + Mui tan: NaCl, KNO3, Na2SO4, BaCl2, AgNO3, ZnCl2, K3PO4...

- Nu 0 < < 1, l cc cht in li yu, khi tan trong nc, ch c mt phn s phn t ho tan phn li ra ion, phn cn li vn tn ti di dng phn t trong dung dch. V d:

+ Cc axit yu nh CH3COOH, H2S, H2CO3, H2SO3, HClO...

+ Cc baz yu nh Mg(OH)2, Cu(OH)2 Th d: CH3COOH CH3COO- + H+


Hng s cn bng in li c k hiu Kin li * Khi pha long dung dch, in li ca cc cht in li u tng.

B. Cc dng bi tp v phng php gii Dng 1:Tnh nng cc ion trong dung dch cht in li

Phng php gii

+ Vit phng trnh in li ca cc cht.

+ Cn c vo d kin v yu cu ca u bi, biu din s mol cc cht trong phng trnh theo tng thi im (ban u, phn ng,cn bng) hoc p dng C=Co. . V d 1. Trn 100 ml dung dch NaCl 0,10M vi 100ml dung dch Na2SO4 0,10M. Xc nh nng cc ion c mt trong dung dch.

Li gii

NaCl, Na2SO4 l nhng cht in li mnh nn ta c

NaCl Na+ + Cl- (1); Na2SO4 2Na+ + SO42- (2) 0,01 0,01 0,01 ; 0,01 0,02 0,01

[Na+] = 1,01,002,001,0

+

+= 0,15M; [Cl-] = 0,05M; [SO42-]= 0,05M

V d 2. Tnh nng mol ca cc ion CH3COOH, CH3COO-, H+ ti cn bng trong dung dch CH3COOH 0,1M c = 1,32%.

Bi gii

CH3COOH H+ + CH3COO- (1) Ban u: Co 0 0

Phn ng: Co. Co. Co.

Cn bng: Co(1-) Co. Co. Vy: [H+]= [CH3COO-] = .Co = 0,1. 1,32.10-2M = 1,32.10-3M

[CH3COOH] = 0,1M 0,00132M = 0,09868M Dng 2: Tnh in li ca dung dch cht Phng php gii



+ Biu din s mol cc cht trong phng trnh theo tng thi im (ban u, phn ng,cn bng) ty theo yu cu v d kin bi ton. + Xc nh nng cht (s phn t) ban u, nng cht (s phn t) trng thi cn bng, suy ra nng cht (s phn t) phn ng (phn li).

+ in li = on

n=

o

NN

=

o

CC

V d 1. Trong 1 lt dung dch CH3COOH 0,02M c cha 1,2407.1022 phn t cha phn li v ion. Tnh in li ca CH3COOH ti nng trn, bit N0=6,022.1023.

Bi gii

3 OOHCH Cn = 0,02 mol S phn t ban u l:

n0 = 1. 0,02.6,022.1023 = 1,2044.1022 phn t

CH3COOH H+ + CH3COO- (1) Ban u n0

Phn ng n n n

Cn bng (n0-n) n n trng thi cn bng c tng s phn t cha phn li v cc ion l:

(n0 n) + n + n = 1,2047.1022 Suy ra: n = 1,2047.1022 1,2044.1022 = 0,0363. 1022 (phn t).

Vy = 22

220

0,0363.10 0,0291,2047.10

n

n= = hay = 2,9%

V d 2. Tnh in li ca axit HCOOH 0,007M trong dung dch c [H+]=0,001M Bi gii

HCOOH + H2O H- + H3O+

Ban u: 0,007 0

Phn ng: 0,007. 0,007.

Cn bng: 0,007(1-) 0,007. Theo phng trnh ta c: [H+] = 0,007. (M) 0,007. = 0,001

= 0

0,001 0,14280,007

CC

= = hay = 14,28%.


V d 3. a) Tnh in li ca dung dch NH3 0,010M. b) in li thay i ra sao khi - Pha long dung dch ra 50 ln.

- Khi c mt NaOH 0,0010M.

Bit: NH3 + H2O NH4+ + OH- ; Kb = ][]].[[

3

4

NHOHNH +

=10-3,36

Bi gii

a) Tnh in li ca dung dch NH3 0,010M: NH3 + H2O NH4+ + OH- Kb = 10-3,36

Ban u: Co Co

phn ng: Co Co Co Co

cn bng: C0(1- ) Co Co

23,360 10

1C

=

= 18,8%

b) * Pha long dung dch ra 50 ln: 3NH

C = 10-2: 50 = 2.10-4M =Co

4 23,362.10 10

1

=

= 74,5%

in li tng v nng cng nh mt ion cng t th kh nng tng tc gia cc ion to cht in li cng gim, in li cng ln.

* Khi c mt NaOH 0,0010M: NaOH Na+ + OH-

NH3 + H2O NH4+ + OH- Kb = 10-3,36 (1)

Ban u: Co Co 0 1. 10-3

phn ng: Co Co Co (Co +10-3) cn bng: C0(1- ) Co (Co +10-3)

V Co = 0,01M 3

3,360 0

0

( ' 10 ). ' 10(1 ').C C

C

+=

= 14,9%

Dng 3: Tnh pH ca dung dch khi bit in li v hng s Ka , Kb Phng php gii


+ Biu din s mol cc cht trong phng trnh theo tng thi im (ban u, phn ng, cn bng) ty theo yu cu v d kin bi ton. + Vi cc cht in li yu l axit HA: HA H+ + A-.

Hng s in li: + -[H ].[A ][HA]aK =

+ Vi cc cht in li yu l baz BOH: BOH B+ + OH -.

Hng s in li: + -[B ].[OH ][BOH]bK =

+ [H+].[OH-] = 10-14

+ Tnh pH ca dung dch axit: Xc nh nng mol/l ca ion H+ trong dung dch trng thi cn bng pH=-lg([H+]) +Tnh pH ca dung dch baz: Xc nh nng mol/l ca ion OH- trong dung dch trng thi cn bng [H+] pH, hoc pH = 14-pOH= 14+lg([OH-]). V d 1. Cho cn bng trong dung dch:CH3COOH + H2O CH3COO- + H3O+ Tnh pH ca dung dch CH3COOH 0,1M (Ka = 1,75.10-5).

Bi gii

CH3COOH + H2O CH3COO- + H3O+

Ban u 0,1 0 0

Phn ng x x x

Cn bng 0,1 - x x x

Ka = ][]][[

3

33

COOHCHCOOCHOH +

= )1,0(2

x

x

= 1,75.10-5

Gi s x

Bi gii

a. Ba(OH)2 Ba2+ + 2OH- Ban u: 0,025 0 0

Phn ng: 0,025. 0,025. 2.0,025.

Cn li: 0,025(1-) 0,025. 2.0,025. Theo phng trnh: [OH-] = 2.0,025. = 2.0,025. 0,8 = 0,04 M

Do tch s ion ca nc: [H+].[OH-] = 10-14 nn [H+] = 14

1410 25.100,04

=

Vy pH = -lg(25.10-14) = 12,60. b. CH3COOH + H2O CH3COO- + H3O+

Ban u: 0,01 0 0

Phn ng: 0,01. 0,01. 0,01.

Cn bng: 0,01(1-) 0,01. 0,01. [H3O+]= [H+] = 0,01. = 0,01.0,0425= 4,25.10-4 Vy pH = -lg(4,25.10-4) = 3,372.

C. Bi tp n luyn

Bi 1. a. Tnh nng mol/l ca ion Ca2+, OH- trong dung dch Ca(OH)2 0,025 M c = 0,8.

b. Tnh nng mol/l ca ion CH3COO- , H+ trong dung dch CH3COOH 0,01 M c = 4,25%.

Bi 2. Tnh nng mol/l ca cc ion trong dung dch CH3COONa 1,087mol/l, bit hng s phn li baz ca CH3COO- l Kb = 5,75.10-10. Bi 3. Tnh nng mol/l ca cc ion trong dung dch HNO2 0,100 mol/l. Bit hng s phn li ca axit HNO2 l Ka = 4,0.10-10.

Bi 4. Tnh th tch dung dch KOH 14% ( d= 1,128 g/ml) c cha s mol OH- bng s mol OH- c trong 0,2 lt dung dch NaOH 5M. Bi 5. Tnh nng mol ca ion H+ trong dung dch NH4Cl 0,1 M. Bit hng s phn li baz Kb(NH3) = 1,8.10-5.


Bi 6. Tnh in ly v pH ca dung dch HCOOH 1M v dung dch HCOOH 102 M. Bit hng s Ka ca HCOOH l 1,7. 10 4. So snh ca HCOOH 2 dung dch . Gii thch.

Bi 7. a. Metytamin trong nc c xy ra phn ng: CH3NH2 + H2O CH3NH3+ + OH- Hng s baz Kb = 4.10-4 .

Hy tnh in li ca metylamin, bit rng dung dch c pH = 12. Tch s ion ca nc l 10-14.

b. in li thay i ra sao (nh tnh) nu thm vo 1 lt metylamin 0,10M: + 0,010 mol HCl.

+ 0.010 mol NaOH.

Bi 8. Mt axit CH3COOH 0,1M c Ka=1,58.10-5. tnh phn li ca axit v PH ca dung dch cha axit CH3COOH 0,1M.

Bi 9. Gi tr PH ca mt axit n l 2,536. sau khi pha long gp i th PH ca dung dch l 2,692.

a. Tnh hng s phn li ca axit.

b. Tnh nng mol/l ca axit ban u.

p s v hng dn gii Bi 1. a. Ba(OH)2 Ba2+ + 2OH-

Ban u: 0,025 0 0

Phn ng: 0,025. 0,025. 2.0,025.

Cn li: 0,025(1-) 0,025. 2.0,025. Theo phng trnh: [OH-] = 2.0,025. = 2.0,025. 0,8 = 0,04 M [Ba2+] = 0,025. = 0,025. 0,8 = 0,02 M b. [H3O+]= [H+] = 0,01. = 0,01.0,0425= 4,25.10-4 M

[CH3COO-] = [H3O+]=4,25.10-4M.

Bi 2. CH3COONa CH3COO- + Na+ 1,087M 1,087M 1,087M


CH3COO- + H2O CH3COOH + OH-

Ban u: 1,087 M 0 0

Phn ng: 1,087. 1,087. 1,087.

Cn bng: 1,087.(1-) 1,087. 1,087. Ta c:

-

3

3 2

[OH ].[ ] (1,087. ).(1,087. ) [ ].[ ] 1,087(1- )b

CH COOHkCH COO H O

= = = 5,75.10-10.

Gi s 1 nn b qua (1-). Suy ra: 1,087. 2 = 5,75.10-10

= 2,3.10-5 tha mn iu gi s.

Vy [ Na+] = 1,087M ; [OH-] = 2,5. 10-5 M. ; [CH3COO-]=1,086975 M. Bi 3. Tng t bi 2.

p s: = 6,3245.10-5 ; [H+] = [NO2-]= 6,3245.10-6 M. Bi 4. nOH- = 0,2.5 = 0,1 mol.

V = dd .100 56.0,1.100 35,461d . (%) 1,128.14

ctm m

d C= = = ml

Bi 5. NH4Cl NH4+ + Cl- 0,1 0,1 0,1

NH4+ + H2O NH3 + H3O+

Ban u 0,1 0 0

Cn bng 0,1 - x x x

Ka = ][]][[

4

33+

+

NHNHOH

= )1,0(2

x

x

;Ka (NH4+) . Kb (NH3) = 10-14

Ka (NH4+) = 10-14.1,8.10-5 = 5,6.10-10 . Gi s x

Ta c: + 2

3

2

[H ].[ ][ ].[ ] (1- )b

O HCOOkHCOOH H O

= = = 1,7. 10 4

Gi s 1 nn b qua (1-). Suy ra: 2 = 1,7. 10 4

= 0,013. tha mn . Hay = 1,3%. Vy [H3O+ ] = 0,013M pH = 1,8848. + Khi [HCOOH]0 = 0,01M.

HCOOH + H2O HCOO- + H3O+

Ban u: 0,01M 0 0

Phn ng: 0,01 0,01 0,01

Cn bng: 0,01(1-) 0,01 0,01

Ta c: + 2

3

2

[H ].[ ] 0,01. '[ ].[ ] (1- ')b

O HCOOkHCOOH H O

= = = 1,7. 10 4 = 0,1222 Hay = 12,22%

Nhn xt: Nng ban u gim th in li tng.

Bi 7. a. CH3NH2 + H2O CH3NH3+ + OH-

Ban u: Co (M) 0 0 Phn ng: . Co Co Co

Cn bng: Co(1-) Co Co Ta c: pH = 12 [H+] = 10-12 [OH-] = 10-2 M Co= 0,01

20.

(1- )bCk

= = 4.10 -4 = 0,03846

b. + Thm 0,01 mol HCl: HCl phn ng vi OH- lm cn bng dch chuyn theo chiu thun nn in li tng ln.

+ Thm 0,010 mol NaOH: NaOH phn li ra ion OH- lm tng nng ion OH-, do cn bng dch chuyn theo chiu nghch(sang bn tri), lm in li gim xung. Bi 8. = 0,01257 hay = = 1,257% ; pH = 2,901 Bi 9. a. Hng s phn li ca axit. Ka = 1,83.10-4

b. Nng mol/l ca axit ban u l 0,049M.


D. Bi tp trc nghim Cu 1. Cho cc cht sau: H2S; H2SO3; CH4; SO2; KHCO3; HF; NaClO; C6H6; Ba(OH)2; C12H22O11. S cht in li l

A. 5. B.6. C.7. D.8. Cu 2. C 3 dung dch , mi dung dch c cha 1 cation v 1 anion trong s cc ion sau (khng trng lp gia cc dung dch): Ba2+, Mg2+, Na+, PO3-4, Cl-, v OH-. Vy 3 dung dch l:

A. Mg3(PO4)2, Ba(OH)2 v NaCl B. Mg(OH)2, Na3PO4 v BaCl2 C. Ba3(PO4)2 , MgCl2 v NaOH. D. MgCl2, Ba(OH)2 v Na3PO4

Cu 3. Nu ta k hiu n, N, C l (s mol, s phn t, nng ) phn li; no, No, CO l (s mol, s phn t, nng ) ban u. phn li chnh l

A. n/no B. N/No C. C/Co D. tt c u ng

Cu 4. Dung dch axit HA 0,1 M (HA H++ A- ) c pH=2. vy c gi tr l A. 0,1 B. 0,01 C. 0,2 D. 0,02

Cu 5. Tng nng cc ion ca dung dch BaCl2 0,01 M l: A. 0,03M B. 0,04 M C. 0,01M D. 0,02M

Cu 6 (2007_khi A): Dung dch HCl v dung dch CH3COOH c cng nng mol/l, pH ca hai dung dch tng ng l x v y. Quan h gia x v y l (gi thit, c 100 phn t CH3COOH th c 1 phn t in li): A. y=x-2. B. y=100x. C. y=x+2. D. y=2x. Cu 7. Trong 1ml dung dch HNO2 c 5,64.1019 phn t HNO2 v 3,60.1018 ion NO2-. in li ca HNO2 trong dung dch l

A. 4,2%. B. 5%. C. 6%. D. 8%. Cu 8. 200ml dung dch natri sunfat 0,2M in li hon ton to ra: A. 0,02mol Na+, 0,04mol SO42- B. 0,04mol Na+, 0,02mol SO42-

C. 0,06mol Na+, 0,04mol SO42- D. 0,08mol Na+, 0,04mol SO42-

Cu 9. Dung dch CH3COOH 0,6% c khi lng ring d = 1g/ml. in li =1%. [H+] trong dung dch c gi tr

A. 0,100M. B. 0,010M. C. 0,001M. D. 0,020M.


Cu 10. Dung dch c cha tng s mol ion bng tng s mol ion ca dung dch CaCl2 1M l dung dch

A. Na3PO4 0,5M B. CuSO4 1M C. Fe2(SO4)3 0,05M D. Na2SO4 1M Cu 11. Khi thay i nhit ca mt dung dch cht in li yu (c nng khng i) th:

A. in li v hng s in li u khng thay i

B. in li thay i v hng s in li khng thay i

C. in li v hng s in li u thay i

D. in li khng i v hng s in li thay i

Cu 12. Hng s cn bng Ka ca axt axetic l 1,8.10-5. in li ca CH3COOH trong dung dch 0,1 M l:

A. 1,43% B. 0,67% C. 1,34% D. 2,34%

Cu 13. Cho cc axit sau: (1). H3PO4 (Ka = 7,6 . 10-3) (2). HOCl (Ka = 5 . 10-8) (3). CH3COOH (Ka = 1,8 . 10-5) (4). HSO4- (Ka = 10-2) Sp xp mnh ca cc axit theo th t tng dn:

A. (2) < (1) < (3) < (4) B. (4) < (1) < (3) < (2) C. 4) < (3) < (1) < (2) D. (2) < (3) < (1) < (4) Cu 14. Trong qu trnh in li, nc ng vai tr:

A. Mi trng in li B. Dung mi khng phn cc

C. Dung mi phn cc D. To lin kt hiro vi cc cht tan

Cu 15. Trong nhng cht sau, cht no l cht in li mnh? 1. NaCl 2. Ba(OH)2 3. Cu(NO3)2 4. H2S 5. Cu(OH)2 6. HClO4 A. 1, 2, 3, 6. B. 1, 4, 5, 6. C. 2, 3, 4, 5. D. 1, 2, 3

Cu 16. Ho tan x mol Al2(SO4)3 vo nc thu c dung dch c cha 0,6 mol SO42-, th gi tr ca x l

A. 1,8 mol

B.

0,4 mol C. 0,2 mol D.

0,6 mol


Cu 17. Dy ch gm cc cht in li yu l A. HF, HCl, HBr, HI, H2O. B. KOH, KF, NaCN, KHCO3.

C. HF, Cu(OH)2, HClO, H2S. D. HI,KCN, CH3COONa, NaHSO3 Cu 18. Mt phn t amoni photphat in li hon ton to ra: A. NH4+, PO43- B. NH4+, 3PO43- C.3NH4+, 2PO43- D. 3NH4+, PO43-

Cu 19. Cho cc yu t: Bn cht ha hc ca cht in li (1); Nhit mi trng (2); nng cht in li (3). in li ca cht in li ph thuc vo yu t A. (1);(2). B. (2); (3). C. (1);(3). D. (1);(2); (3). Cu 20. Dung dch CH3COOH trong nc c nng 0,1 M, = 1% c pH l: A. 11 B. 3 C. 5 D. 7.

P N V HNG DN 1.B 2.D 3.D 4.A 5.A 6.C 7.C 8.D 9.C 10.D

11.C 12.C 13.D 14.C 15.A 16.C 17.C 18.D 19.D 20.B

Cu 4. HA H+ + A-

Ban u: 0,1

Phn ng: 0,1 0,1 0,1

Cn bng: 0,1 (1 ) 0,1 0,1 20,1 2 10H pH H M+ + = = =

20,1 10 0,1 10% = = =

Cu 6. HCl l axit mnh 1 = ,ta c: HCl H + + Cl

00 10

10x

x

H CC

pH x H

+

+

= =

= =

(1)

V c 100 phn t CH3COOH th c 1 phn t in li 1 0,01

100 = =


3CH COOH 3CH COO

+ H +

b 0C

p 0C 0C 0C

cb 0 (1 )C 0C 0C

+ 0pH= y H 10 10y y C = =

20

10 10 100,01

y yyC

+= = = = (2)

t (1),(2) 210 10 2x y x y + = + =

Cu 7. 18

19 183,6.10

.100 6%5,64.10 3,6.10

= =+

Cu 9. 3CH COOH 3CH COO

+ H +

Gi nng ban u ca 3CH COOH l 0C (M) H + = 0C

Xt 1 lt dung dch V = 1000ml

MMCd

MC

Vm

MVm

VnC ddct 1,0

100.601000.6,0

.1100.

(%)..

1000100.(%)

.

.

0 ======

H + = 0C = 0,1.0,01 = 0,001 M C


+ H +

0C

0 (1 )C 0C 0C 2

50 0 0

0

. ( ) 1,8.10(1 ) 1C C CKaC

= = =

. 0 0,1C M= 2 4 51,8.10 1,8.10 0 + =

0,01330,0136

B

=

=


+ H +

H + = 0C =0,1.0,01=310 3pH =


2. AXIT, BAZ V MUI. S IN LI CA NC pH, CHT CH TH AXIT- BAZ A. Hng dn t n l thuyt 1.Thuyt axit baz ca Areniut - Axit: l cht khi tan trong nc phn li ra ion H+

+ Axit ch phn li mt nc ra ion H+ gi l axit mt nc :HCl H+ + Cl-

+ Axit m phn t phn li nhiu nc ra ion H+ gi l axit nhiu nc, th d:

H2SO4 H+ + HSO4-+ ; HSO4- H+ + SO42-

- Baz: l cht khi tan trong nc phn li cho ion OH-

+ Baz ch phn li mt nc ra ion OH- gi l baz mt nc: NaOH Na+ + OH-

+ Baz m phn t phn li nhiu nc ra ion OH- l baz nhiu nc, th d:

Ca(OH)2 Ca(OH)+ + OH- ; Ca(OH)+ Ca2+ + OH- - Hiroxit lng tnh: l cht khi tan trong nc va c th phn li nh axit, va c th phn li nh baz. Th d:

Zn(OH)2 Zn2+ + 2OH- (phn li kiu baz) Zn(OH)2 (hay H2ZnO2) 2H+ + ZnO22-

Hiroxit lng tnh thng gp l: Al(OH)3, Pb(OH)2, Cr(OH)3, Sn(OH)2. 2. Thuyt axit-baz ca Bron-stt - nh ngha: axit l cht nhng proton (H+), baz l cht nhn proton

Axit Baz + H+

Theo thuyt ny, H2O l hp cht lng tnh: H2O + H2O H3O+ + OH-

- Hng s phn li axit: S phn li ca axit yu trong nc l qu trnh thun nghch, hng s cn bng phn li axit ny c k hiu l Ka. Ging nh tnh cht ca hng s cn bng, Ka ch ph thuc vo bn cht axit v nhit .

+ Th d, :CH3COOH H+ + CH3COO-

Ka ca axit CH3COOH c biu din nh sau Ka = COOHCH

COOCHH3

3 ]][[ +

hoc CH3COOH + H2O H3O + + CH3COO- Ka = COOHCH

COOCHOH3

33 ]][[ +


trong [H+], [CH3COO-], [CH3COOH] l nng mol.l ca H+, CH3COO-, CH3COOH lc cn bng.

+ Gi tr Ka ca axit cng nh, lc axit (tnh axit) ca n cng yu. Th d, 250C, Ka ca CH3COOH l 1,75.10-5 v ca HClO l 5.10-8. Vy lc axit ca HClO yu hn ca CH3COOH.

- Hng s phn li baz: Hng s cn bng phn li baz c k hiu l Kb, n ch ph thuc vo bn cht baz v nhit . Gi tr Kb ca baz cng nh, lc baz (tnh baz) ca n cng yu.

Th d: NH3 + H2O NH4+ + OH- c Kb = ][]][[

3

4

NHOHNH +

- Mui: l hp cht khi tan trong nc phn li ra cation kim loi (hoc NH4+) v anion gc axit.

+ Mui trung ho: l mui trong phn t khng cn kh nng phn li ra ion H+.

Th d: K2SO4 2K+ + SO42-

+ Mui axit: l mui trong phn t vn cn hiro c kh nng phn li ra ion H+

Th d: NaHCO3 Na+ + HCO3- ; HCO3- H+ + CO32-

Ch : Na2HPO3, NaH2PO2 vn cn hiro trong phn t nhng khng phi l mui axit + Mui phc tp: mui kp, th d NaCl.KCl; mui phc, th d [Ag(NH3)2]Cl

NaCl.KCl Na+ + K+ + 2Cl-

[Ag(NH3)2]Cl [Ag(NH3)2]+ + Cl- [Ag(NH3)2]+ Ag+ + 2NH3

Kt lun: Thuyt axit-baz ca Bron-stt tng qut hn thuyt axit-baz ca Areniut v c tnh nh lng (da vo Ka, Kb ta bit lc axit v lc baz). 3. Khi nim v pH

- Tch s ion ca nc: OHK 2 = [H+][OH-] = 10-14 250C, l hng s nhit khng i.

Trong dung dch long ca cc cht khc nhau 250C lun c [H+][OH-] = 10-14. Th d: trong dung dch c nng H+ = 10-3M

nng OH- l: [OH-] = 10-14. [H+] = 10-14. 10-3 = 10-11. - Quy c pH = -lg[H+] hay [H+] = 10-pH th nu [H+] = 10-a, pH = a


+ Mi trng trung tnh, [H+] = [OH-] = 10-7, pH =7 + Mi trng axit: [H+] > 10-7 nn pH 7 B. Cc dng bi tp v phng php gii

Dng 1: Tnh gi tr pH ca dung dch + Tnh pH ca dung dch axit: Xc nh nng mol/l ca ion H+ trong dung dch trng thi cn bng pH=-lg([H+]) +Tnh pH ca dung dch baz: Xc nh nng mol/l ca ion OH- trong dung dch trng thi cn bng [H+] pH, hoc pH = 14-pOH= 14+lg([OH-]). V d 1. Trn 100 ml dung dch gm Ba(OH)2 0,1M v NaOH 0,1M vi 400 ml dung dch gm H2SO4 0,0375 M v HCl 0,0125 M thu c dung dch X. Tnh pH ca dung dch X .

Li gii

H+ + OH- H2O

Tng s mol OH-: (0,1.2 + 0,1).0,1 = 0,03 mol Tng s mol H+ : (0,0375.2 + 0,0125).0,4 = 0,035 mol S mol H+ d: 0,035 0,03 = 0,005 mol [H+]= 0,01M pH = 2 V d 2. Cho dung dch A l mt hn hp: H2SO4 2.10-4M v HCl 6.10-4M

Cho dung dch B l mt hn hp: NaOH 3.10-4M v Ca(OH)2 3,5.10-4M a) Tnh pH ca dung dch A v dung dch B b) Trn 300ml dung dch A vi 200ml dung dch B c dung dch C. Tnh pH ca dung dch C.

Li gii

a. [ H+] trong A: 2.2.10-4 + 6.10-4 = 10-3 mol pH = 3 [OH-] trong B: 3.10-4 + 2.3,5.10-4 = 10-3 mol pOH = 3 pH =11

b. Trong 300ml dung dch A c s mol H+ = 0,3.10-3 mol

Trong 200 ml dung dch B c s mol OH- = 0,2.10-3 mol

Dung dch C c: V = 0,5 lt; s mol H+ = 0,3.10-3 - 0,2.10-3 = 10-4 mol

Vy [H+] = 410

0,5

2.10-4 M pH = 3,6989


Dng 2: Pha trn dung dch Phng php gii

+ S dng phng php ng cho, ghi nh: Nc c C% hoc CM =0.

+ Xc nh s mol cht, pH [H+] mol H+ hoc mol OH-. + Vic thm, c cn nc lm thay i nng mol/l v khng lm thay i s mol cht tnh ton theo s mol cht.

V d 1. 1. Dung dch HCl c pH=3. Hi phi pha long dung dch HCl bng nc bao nhiu ln c dung dch HCl c pH = 4. Gii thch?

2. Pha thm 40cm3 nc vo 10 cm3 dung dch HCl c pH=2. Tnh pH ca dung dch sau khi pha thm nc.

Li gii

1. Gi s dung dch HCl ban u c th tch V1 (l), pH = 3. S mol H+ ban u l V1.10-3 mol ; Th tch H2O cn thm vo l V2 (l).

S mol H+ trong dung dch pH= 4 l (V1 + V2 ).10-4 Vic pha long dung dch ch lm thay i nng mol/l ch khng lm thay i s mol H+. V vy : (V1 + V2 ).10-4 = V1.10-3 9 V1 = V2 Vy phi pha long dung dch gp 10 ln (nc thm vo gp 9 ln th tch ban u) 2. 1dm3 = 1 lt; 1cm3 = 10-3 lt. S mol H+ l 10.10-3. 0,01 = 10-4 mol.

Thm 40.10-3 lt nc th th tch dung dch l 50.10-3 lt.

Vic pha long khng thay i s mol H+

nn: CM(H+) =4

310

50.10

= 0,002M

pH = 2,6989

V d 2. Thm t t 400 gam dung dch H2SO4 49% vo H2O v iu chnh lng H2O thu c ng 2 lt dung dch A. Coi H2SO4 in li hon ton 2 nc.

a. Tnh nng mol/l ca ion H+ trong dung dch A

b. Tnh th tch dung dch NaOH 1,8M cn thm vo 0,5 lt dung dch A thu c + dung dch c pH= 1

+ dung dch c pH= 13

Li gii

a. H2SO4 2H+ + SO42-


S mol H+ : 49.400 2 498.100

mol= CM(H+) = 42 =2M

b.Th tch dung dch NaOH cn thm vo pH =1.

H+ + OH- H2O

2.0,5 V.1,8

V pH = 1 [H+] = 0,1 s mol H+ sau phn ng: = (0,5 + V) .0,1 ( mol) 0,5.2 1,8.V = (0,5 + V) .0,1 V = 0,5 lt.

+ Th tch dung dch NaOH cn thm vo pH =13.

V pH = 13 [OH-] = 0,1M S mol OH- sau phn ng: (0,5 + V).0,1 mol V.1,8 -2.0,5 = (0,5 + V) .0,1 V = 0,0882 lt. C. Bi tp n luyn Bi 1. Ch dng thm qu tm hy trnh by cch phn bit cc dung dch ng trong cc l ring bit mt nhn sau:

a) NH4Cl ; (NH4)2SO4; BaCl2 ; NaOH ; Na2CO3 b) Na2SO4; BaCl2 ; KNO3; Na2CO3

Bi 2. 1.Thm t t 100 gam dung dch H2SO4 98% vo nc v iu chnh c 2 lt dung dnh X. tnh nng mol/l ca dung dch X.

2. Tnh t l th tch dung dch KOH 0,001M cn pha long vi nc c dung dch c PH=9.

Bi 3. Dung dch thu c khi trn ln 200 ml dd NaCl 0,3M v 300ml dung dch Na2SO4 0.15 M nu b qua hiu ng th tch th dung dch thu c c nng Na+ l bao nhiu? Bi 4. Ha tan 20 ml dung dch HCl 0,05 mol/l vo 20 ml dung dch H2SO4 0,075 mol/l. coi th tch thay i khng ng k. Tnh PH ca dung dch thu c.

Bi 5. Cho 200ml dung dch HNO3 c PH=2. tnh khi lng HNO3 c trong dung dch. Nu thm 300 ml dung dch H2SO4 0,05M vo th PH ca dung dch thu c l bao nhiu? Bi 6. Trn 300 ml dung dch NaOH 0,1 mol/lit v Ba(OH)2 0,025 mol/l vi 200 ml dung dch H2SO4 nng x mol /lit Thu c m gam kt ta v 500 ml dung dch c PH = 2 . Hy tnh m v x . Coi H2SO4 in li hon ton c hai nc .

Bi 7. X l dung dch H2SO4 0,02M. Y l dung dch NaOH 0,035M. Khi trn ln dung dch X v dung dch Y ta thu c dung dch Z c th tch bng tng th tch 2 dung dch em


trn v c pH=2. Coi H2SO4 in li hon ton 2 nc. Hy tnh t l th tch gia dung dch X v dung dch Y

Bi 8.Cho m gam hn hp Mg , Al vo 250 ml dung dch X cha hn hp axit HCl 1M v axit H2SO4 0,5M thu c 5,32 lt kh H2 ktc v dung dch Y. Tnh PH ca dung dch Y ( Coi dung dch c th tch nh ban u ) . Bi 9. Trn 200 ml dung dch NaHSO4 0,2M v Ba(HSO4)2 0,15M vi V lit dung dch hn hp NaOH 1M v Ba(OH)2 1M thu c dung dch c PH = 7. Tnh V v khi lng kt ta to thnh.

Bi 10. Trn 250 ml dung dch hn hp HCl 0,08 mol/l v H2SO4 0,01 mol /l vi 250 ml dung dch Ba(OH)2 c nng x mol /l thu c m gam kt ta v 500 ml dung dch c pH = 12 . Hy tnh m v x . Coi Ba(OH)2 in li hon ton c hai nc .

p n v hng dn gii Bi 1. 1. Dng giy qu tm:

+ Dung dch lm qu tm chuyn : NH4Cl ; (NH4)2SO4; (nhm 1) + Dung dch khng lm qu tm chuyn mu: BaCl2

+ Dung dch lm qu tm chuyn mu xanh: NaOH ; Na2CO3(nhm 2) - Ly dung dch BaCl2 cho vo cc nhm trn:

+ Nhm 1: * Va c kt ta, c kh mi khai l (NH4)2SO4. * Dung dch c kh mi khai thot ra l NH4Cl.

+ Nhm 2: * C kt ta l Na2CO3

* Cn li l NaOH.

2. Na2SO4; BaCl2 ; KNO3; Na2CO3.

Dng giy qu tm:

+ Dung dch khng lm qu tm chuyn mu: Na2SO4; BaCl2 ; KNO3

+ Dung dch lm qu tm chuyn mu xanh: Na2CO3

- Ly dung dch Na2CO3 cho vo nhm trn:

* C kt ta l BaCl2: Na2CO3 + BaCl2 BaCO3 + 2NaCl

* Khng c hin tng l: Na2SO4; KNO3


- Ly dung dch BaCl2 cho vo Na2SO4; KNO3

+ C kt ta l Na2SO4: Na2SO4 + BaCl2 BaSO4 + 2NaCl

+ Khng c hin tng l KNO3

Bi 2. 1.CM(X) = 1M 2. VK2O / VH2O =1/99

Bi 3. Nng Na+: 0,2.0,3 + 0,3.2.0,15 = 0,15mol Vy CM(Na+) = 0,3M

Bi 4. PH=1.

Bi 5. [H+]= 0,01M s mol H+ = HNO3 = 0,002mol. Khi lng HNO3 = 0,126 gam

Thm H+: 0,03 mol Tng mol H+: 0,032 mol [H+]= 0,064M pH= 1,1938

Bi 6. pH= 2 [H+] =0,01 M; 0,2.x (0,1 +0,025.2).0,3 = 0,01.0,5 x=0,25M Khi lng kt ta: m = 0.0075.233= 1,7475 gam

Bi 7. H+ + OH- H2O VX.0,02.2 VY. 0,035

VX.0,02.2 - VY. 0,035 = 0,01.( VX + VY) VX/VY = 3/2. Bi 8. p s pH = 1. Bi 9. NaHSO4 Na+ + HSO4- ; Ba(HSO4)2 Ba2+ + 2HSO4- HSO4- + OH- H2O + SO42-

(0,04 +0,06) 4V (0,04 +0,06) Do pH = 7 nn 0,1 = 4V V = 0,025(lit) Ba2+ + SO42- BaSO4

0,375 0,1 nBaSO4 = nBa2+ = 0,375 mol.

Vy: khi lng BaSO4 l 87,375 gam.

Bi 10. pH= 12 [OH-] =0,01 M; 0,25.2.x (0,08 +0,01.2).0,25 = 0,01.0,5 x=0,06M


Khi lng kt ta: m = 0,0025.233= 0,5825gam

D. Bi tp trc nghim Cu 1. Cho cc cht: Al, Al2O3, Al2(SO4)3, Zn(OH)2, NaHS, K2SO3, (NH4)2CO3. S cht u phn ng c vi dung dch HCl, dung dch NaOH l

A. 7. B. 6. C. 4. D. 5. Cu 2. Chn cu pht biu sai. Dung dch mui

A. CH3COOK c pH >7. B. NaHCO3 c pH.

Cu 10. Cho 500 ml dung dch HCl 0,02M vi 500ml dung dch NaOH 0,018M c mt dung dch mi c pH l:

A. 3 B. 2,7 C. 5 D. 4,6 Cu 11. Tm cu tr li sai trong s cc cu sau y v pH:

A. pH = lg[H+] B. pH + pOH = 14 C. pH = -lg[H+] D. pH = 14 + lg[OH-]

Cu 12(H,2007-A). Trn 100ml dung dch (gm Ba(OH)2 0,1M v NaOH 0,1M) vi 400 ml dung dch (gm H2SO4 0,0375 M v HCl0,0125M), thu c dung dch X. Gi tr pH ca dung dch X l

A. 7 B. 2 C. 1 D. 6

Cu 13. Cho cc phn ng sau: HCl + H2O = H3O+ + Cl- (1) NH3 + H2O = NH4+ + OH- (2) CH3COOH + H2O = CH3COO- + H3O+ (3) HSO3- + H2O = H2SO3 + OH- (4) HCO3- + H2O = H3O+ + CO32- (5) CuSO4 + 5H2O = CuSO4.5H2O (6) Theo thuyt bronsted, H2O ng vai tr l axit trong cc phn ng sau:

A. (1), (3), (5). B. (2), (4). C. (2), (4), (6). D. (1), (3), (5), (6). Cu 14. Trn V1 lt dung dch HCl (pH=5) vi dung dch V2 lt NaOH(pH=9) thu c dung dch c pH=6. T l V1/V2 l:

A. 3/1 B. 1/3 C. 9/11 D.11/9

Cu 15. Nng ion OH- trong dung dch A l 1,8.10-5 M. pH ca dung dch A l A.7,25M B. 5,25M C.9,25M D. 11,25M Cu 16. Cho cc dung dch mui sau, dung dch c pH > 7 l (X1) KCl; (X2) Na2CO3; (X3) CuSO4; (X4) CH3COONa (X5) ZnSO4; (X6) AlCl3 ; (X7) NaCl ; (X8) NH4Cl. A. X1, X2, X4, X7 B. X2, X4, X8 C. X1, X3, X4, X6 D. X2, X4 Cu 17. (H, C khi A-2007). Cho dy cc cht: Ca(HCO3)2, NH4Cl, (NH4)2CO3, ZnSO4, Al(OH)3, Zn(OH)2. S cht trong dy c tnh lng tnh l:

A. 3. B. 4. C. 2. D. 5.


Cu 18. Cho cc dung dch c nh s th t nh sau: 1. KCl 2. Na2CO3 3. CuSO4 4. CH3COONa

5. Al2(SO4)3 6. NH4Cl 7. NaBr 8. K2S Cc dung dch u c pH < 7 l:

A. 3, 5, 6 B. 2, 4, 6 C. 1, 2, 3 D. 6, 7, 8 Cu 19. Th tch KOH 0,001M cn pha 1,5 lt dung dch c pH=9 l: A.3.10-2 lt B. 2,5.10-2 lt C. 1,5.10-3 lt D. 1,5.10-2lit Cu 20. Nh dung dch phenolphtalein vo dung dch no sau y, dung dch chuyn sang mu hng?

A. AlCl3 B. MgCl2 C. Na2S D. NH4NO3

p n v hng dn

1.D 2.B 3.C 4.B 5.A 6.D 7.A 8.B 9.A 10.B

11.A 12.B 13.B 14.D 15.C 16.D 17.B 18.A 19.D 20.C

Cu1

2) 2 3 3 26 2 3Al O HCl AlCl H O+ + ; 2 3 2 22 2Al O NaOH NaAlO H O+ + 3) 3 2 2( ) 2Zn OH HCl ZnCl H O+ + ; 2 2 2 2Zn(OH) 2 2NaOH Na ZnO H O+ + 4) 2NaHS HCl NaCl H S+ + ; 2 2NaHS NaOH Na S H O+ + 5) 4 2 3 4 2 2( )NH CO HCl NH Cl H O CO+ + +

4 2 3( )NH CO + NaOH 32NH + 2 3 2Na CO H O+ Cu 2. 22 4 42H SO H SO+ +

Trong 2lt dung dch axit 2 4H SO (pH=2) c: 22.10 0,02( )Hn mol+ = = g/s thm m (g) khng lm thay i th tch dd,ta c: trong 2lt dd axit 2 4H SO (pH=1): 12.10 0, 2( )Hn mol+ = =

vy s mol 2 4H SO thm vo l:0,2 0,02 0,09( )

2mol =

2 40,09.98 8,82( )H SOm gam = =


Cu 3. Gi s th tch dung dch KOH 310 l 1V 31.10OHn V =

thm 2V (l) nc vo dung dch thu c ( 1V + 2V )l dd KOH 510 OHn =( 1V + 2V ). 510

Vy: 31.10V

=( 1V + 2V ). 510 cn pha long 100 ln A Cu 12.

100ml 2( ) 0,1

0,1Ba OH MNaOH M

0,03( )OHn mol =

400ml 2 40,0375 (0,0375.2 0,0125).0, 4 0,035

0,01251 HH SO M

n molHClO M +

= + =

H + + OH 2H O

0,035 0,03

d: 0,005 0 0,005 H

n + d =0,005 0,005 0,01 2

0,5H pH+ = = =

Cu 14. 1V (l) dd HCl pH=5 Hn + = 510 1V (mol)

2V (l) dd NaOH pH=9 pOH=5 OHn = 510 2V (mol)

H + + OH 2H O

510 1V 510 2V

do: 6 7pH axit= < d 1V .510 > 2V

510 v 61 2( ).10H V V+ = +

1V .510 - 2V

510 = 61 2( ).10V V + 12

119

V DV

=

Cu 19. pH=9 pOH=5 OHn =1,5. 510 .g/s th tch KOHV ban u l V(l)

OHn =V.0,001 1,5. 510 =V. 310 V=1,5. 210 (l) D.


3. PHN NG TRAO I ION TRONG DUNG DCH CC CHT IN LI A. Hng dn t n l thuyt 1. iu kin xy ra phn ng trao i ion - Phn ng to thnh cht kt ta:

Th d, phng trnh phn t: Na2SO4 + BaCl2 BaSO4 + 2NaCl Phng trnh ion y : 2Na+ + SO42- + Ba2+ + 2Cl- BaSO4 + 2Na+ + 2Cl- Phng trnh ion rt gn: SO42- + Ba2 BaSO4 - Phn ng to thnh cht in li yu:

+ Phn ng to thnh nc:

Th d: NaOH + HCl NaCl + H2O

Phng trnh ion rt gn: OH- + H+ H2O

+ Phn ng to thnh axit yu:

Th d: HCl + CH3COONa NaCl + CH3COOH

Phng trnh ion rt gn: H+ + CH3COO- CH3COOH

- Phn ng to thnh cht kh:

Th d: Na2CO3 + H2SO4 Na2SO4 + H2O + CO2 Phng trnh ion rt gn: CO32- +2H+ H2O + CO2

Kt lun: Phn ng trao i ion trong dung dch cc cht in li ch xy ra khi c t nht mt trong cc iu kin: to thnh cht kt ta, cht kh, hoc cht in li yu.

2. Phn ng thu phn ca mui - Khi nim v s thu phn ca mui: phn ng trao i ion gia mui ho tan v nc l phn ng thu phn ca mui.

- Phn ng thu phn ca nc: nc nguyn cht c pH = 7, i a s phn ng thu phn lm thay i pH ca nc.

+ Mui trung ho to bi cation ca baz mnh v gc axit yu, khi tan trong nc gc axit yu b thu phn, mi trng ca dung dch l kim (pH >7). Th d CH3COONa, K2S, Na2CO3.

Th d, dung dch CH3COONa c pH > 7 c gii thch nh sau:


CH3COONa CH3COO- + Na+


Cc anion OH- c gii phng sau phn ng thy phn, nn mi trng c pH > 7

+ Mui trung ho to bi cation ca baz yu v gc axit mnh, khi tan trong nc, cation ca baz yu b thu phn lm cho dung dch c tnh axit (pH

5. NaHCO3 + Ba(OH)2 ; 6. Ba(HSO4)2 + KOH 7. KH2PO4 + HCl ; 8. NH4Cl + NaOH

9. CaCO3+ CO2 + H2O ; 10. FeCl3 + Na2CO3 + H2O

Li gii

1. Fe2(SO4)3 + 6NaOH 2Fe(OH)3 + 3Na2SO4; Fe3+ + 3OH- Fe(OH)3 2. Cu(OH)2 + 4NH3 + H2O [Cu(NH3)4](OH)2 (phc tan); Cu(OH)2 + 4NH3 [Cu(NH3)4]2+ + 2OH- 3. KNO3 + NaCl khng phn ng

4. FeS + 2HCl FeCl2 + H2S ; FeS + 2H+ Fe2+ + H2S 5. 2NaHCO3 + Ba(OH)2 BaCO3 + Na2CO3 +2H2O HCO3-+ Ba2+ + OH- BaCO3 + H2O 6. Ba(HSO4)2 +2KOH BaSO4 + K2SO4 + 2H2O Ba2+ + HSO4- + OH- BaSO4 + H2O

7. KH2PO4 + HCl KCl + H3PO4 ; HPO42- + 2H+ H3PO4

8. NH4Cl + NaOH NH3 + NaCl + H2O ; NH4+ + OH- NH3 + H2O

9. CaCO3+ CO2 + H2O Ca(HCO3)2 ; CaCO3+ CO2 + H2O Ca2+ + 2HCO3-. 10. 2FeCl3 + 3Na2CO3 + 3H2O 2Fe(OH)3 + 6NaCl + 3CO2. 2Fe3+ + 3CO32- + 3H2O 2Fe(OH)3 + 3CO2.

Dng 2: Xc nh mi trng dung dch Phng php gii

+ Vit phng trnh in li cc cht to thnh ion, nhn xt kh nng thy phn trong nc ca cc ion va to thnh.

+ Ion gc ca axit yu thy phn trong nc to mi trng baz: CO32-; SO32-; S2-, PO43-, CH3COO-...

+ Ion gc ca baz yu thy phn trong nc to mi trng axit: Cu2+, Fe3+; Zn2+, NH4+..

+ Ion gc ca axit mnh (v d: SO42-, Br-, Cl-, NO3-, ClO4-...) v ion gc ca baz mnh (v d: Na+; K+, Ba2+, Ca2+, Mg2+...) khng b thy phn trong nc, ng vai tr trung tnh.


V d 1. nh gi mi trng axit, baz, trung tnh ca cc dung dch thu c khi ha tan cc cht sau vo cc cc nc ring bit: CuCl2; Na2CO3; NaClO4; K2S; NH4Cl; Fe(NO3)3; Na3PO4 ; K2SO3, K2SO4 .

Li gii

- Cc cht ha tan trong nc cho mi trng baz, pH>7 l: Na2CO3; K2S; K2SO3, Na3PO4.

Na2CO3 2Na+ + CO32- ; CO32- + H2O HCO3- + OH-

K2S 2K+ + S2- ; S2- + H2O HS- + OH-

K2SO3 2K+ + SO3 2- ; SO3 2- + H2O HSO3 - + OH-

Na3PO4 3Na+ + PO43- ; PO43- + H2O HPO42- + OH-

- Cc cht ha tan trong nc cho mi trng axit, pH


ClO-+ H2O HClO + OH-

- Ion c tnh lng tnh l: HCO3-; HPO42- ; HS-, HSO3-; H2PO4-.

HCO3- + H2O CO2 + H3O+ ; HCO3- + H2O CO32- + OH-.

HS- + H2O SO2 + H3O+ ; HS- + H2O S2- + OH-.

HPO42-+ H2O PO43-+ H3O+ ; HPO42- + H2O H2PO4-+ + OH-.

- Ion trung tnh l: SO42-, Cl- , NO-3; Na+; Ba2+; ClO4-; I-.

Dng 3: p dng nh lut bo ton in tch (LBTT)

Phng php gii + nh lut bo ton in tch: Trong mt dung dch, tng s mol cc in tch dng ca ion dng v tng s mol cc in tch m ca ion m lun lun bng nhau.

+ Khi c cn dung dch, khi lng cht rn to ra bng khi lng cc ion dng v ion m c trong dung dch (tr H+ + OH- H2O ) mmui = mcation/NH4+ + manion.

V d 1. Mt dung dch cha: a mol Na+ ; b mol Ca2+ ; c mol Al3+; d mol Cl- ; e mol NO3-. a- Lp biu thc lin h gia a, b, c, d, e.

b- Lp cng thc tnh tng khi lng cc mui trong dung dch theo a, b, c, d, e.

Li gii

a. Lp biu thc lin h gia a, b, c, d, e.

p dng nh lut bo ton in tch ta c: a + 2b + 3c =d + e

b.Tnh tng khi lng cc mui trong dung dch

Khi lng mui = Tng khi lng cc ion = 23a + 40b + 27c + 35,5d + 62e V d 2. Dung dch A cha a mol Na+; b mol NH4+; c mol HCO3-; d mol CO32- ; e mol SO42-

. Thm (c + d + e) mol Ba(OH)2 vo dung dch A, un nng thu c kt ta B, dung dch X v kh Y duy nht c mi khai. Tnh s mol ca mi cht trong kt ta B, kh Y v mi ion trong dung dch X theo a, b, c, d, e. Nu c cn dung dch thu c, lm khan c m gam cht rn. Tnh m theo a, b, c, d, e?

Li gii


Ba(OH)2 Ba2++ 2OH-; s mol Ba2+ = c + d + e; s mol OH- = 2(c + d + e) Cc phng trnh ha hc xy ra khi cho Ba(OH)2 vo dung dch A: OH- + NH4+ NH3 + H2O (1) ; OH- + HCO3- CO32- + H2O (2)

b b mol c c mol

Ba2+ + CO32- BaCO3 (3) ; Ba2+ + SO42- BaSO4 (4) (c + d) (c + d) mol e e mol

Kt ta B: BaCO3, BaSO4

p dng L BTT cho dung dch A:a + b = c + 2d + 2e a + b + c = 2(c + d + e). T (1) v (2) OH- d a mol Vy, t (1): s mol NH3 = b mol; s mol BaCO3 = c + d; s mol BaSO4 = e Dung dch X gm a mol Na+ khng tham gia phn ng v a mol OH- d.

C cn, lm khan thu amol NaOH, khi lng NaOH = 40a (gam).

Dng 4: Bi tp nhn bit

Phng php gii + Vit phng trnh in li, nhn xt kh nng thy phn trong nc ca cc ion , xc nh mi trng dung dch c to thnh.

+ Ha cht dng nhn bit cn c phn ng vi hin tng (to kh, to kt ta, i mu) vi cc cht cn nhn bit:

* Dy cht cn nhn bit c cha ion kim loi Fe2+, Fe3+, Cu2+, Al3+, Zn2+...hay ion NH4+ th nn dng NaOH, Ba(OH)2, Ca(OH)2 ... * Dy cht cn nhn bit c cha ion CO32-; SO42-; SO32- ...th nn s dng cc cht c cha ion Ba2+, Ca2+, H+...

V d 1. Ch dng thm mt thuc th hy trnh by phng php ha hc phn bit cc dung dch sau: NH4HSO4; HCl; H2SO4; NaCl; CH3COONH4; BaCl2; Ba(OH)2. Vit cc phng trnh ha hc ca phn ng xy ra.

Li gii

Dng giy qu tm:

+ Dung dch lm qu tm chuyn : NH4HSO4; HCl; H2SO4 (nhm 1)


+ Dung dch khng lm qu tm chuyn mu: NaCl; CH3COONH4; BaCl2 (nhm 2) + Dung dch lm qu tm chuyn mu xanh: Ba(OH)2. - Ly dung dch Ba(OH)2 cho vo cc nhm trn: + Nhm 1: * Va c kt ta, c kh mi khai l NH4HSO4.

* Ch to kt ta l dung dch H2SO4 * Cn li l dung dch HCl.

+ Nhm 2: * Dung dch c kh mi khai thot ra l CH3COONH4.

* Ly dung dch H2SO4 nhn bit trn nhn bit NaCl v BaCl2.

V d 2. C cc l ng cc dung dch ring bit mt nhn sau: AlCl3; NaNO3; FeCl2; K2CO3; NH4NO3; (NH4)2CO3. Ch c dng thm mt dung dch lm thuc th phn bit cc dung dch trn. Hy trnh by phng php phn bit tng dung dch trn v vit phng trnh ha hc dng phn t v ion minh ha.

Li gii

Chn dung dch Ba(OH)2 ln lt cho tc dng vi cc dung dch cn phn bit. - Dung dch to kt ta sau tan khi Ba(OH)2 d l dung dch AlCl3. 2AlCl3 + 3Ba(OH)2 2Al(OH)3 + 3BaCl2 Al3+ + 3OH- Al(OH)3 Al(OH)3 + OH- AlO2- + 2H2O. - Dung dch to kt ta trng xanh, sau chuyn sang mu nu l dung dch FeCl2.

FeCl2 + Ba(OH)2 Fe(OH)2 + BaCl2 Fe2+ + 2OH- Fe(OH)2 4Fe(OH)2 + O2 + 2H2O 4Fe(OH)3 - Dung dch to kt ta trng l dung dch K2CO3.

K2CO3 + Ba(OH)2 BaCO3 + 2NH3 + 2H2O CO32- + Ba2+ BaCO3 + 2H2O.

- Dung dch to kt ta trng v c kh thot ra l dung dch (NH4)2CO3. (NH4)2CO3 + Ba(OH)2 BaCO3 + 2NH3 + 2H2O 2NH4+ + CO32- + Ba2+ + 2OH- BaCO3 + 2NH3 + 2H2O.

- Dung dch c kh thot ra l dung dch NH4NO3.


2NH4NO3 + Ba(OH)2 Ba(NO3)2 + 2NH3 + 2H2O NH4+ + OH- NH3 + H2O

- Dung dch khng c hin tng g l NaNO3.

Dng 5: Bi tp s dng phng trnh ion thu gn + Vi dung dch c cha nhiu ion, xc nh kh nng phn ng ca cc ion to kt ta, to kh, to cht in li yu hn, vit phng trnh phn ng dng ion thu gn (ch nn vit phng trnh lin quan n yu cu ca bi ton). + Biu din nng cc cht theo phng trnh ion, da trn d kin v yu cu u bi.

+ p dng nh lut bo ton in tch (nu cn). V d 1. Mt dung dch X cha 0,15 mol Na+, 0,10 mol Mg2+, 0,05 mol Cl-, 0,10 mol HCO3- v a mol SO42-. Cn thm V lt dung dch Ba(OH)2 1M thu c lng kt ta ln nht. a) Xc nh gi tr ca V? b) Gi s th tch dung dch thu c sau phn ng l 1,0 lt, xc nh pH ca dung dch.

Li gii

a) p dng LBTT: 0,15 + 0,1.2 = 0,05 + 0,1 + 2a a = 0,1mol Ba(OH)2 Ba2+ + 2OH- (1); Mg2+ + 2OH- Mg(OH)2 (2) xmol xmol 2xmol 0,1 0,2

HCO3- + OH- CO32- + H2O (3); Ba2+ + SO42- BaSO4 (4) 0,1 0,1 0,1 0,1

Ba2+ + CO32- BaCO3 (5). 0,1 0,1

Nu tnh theo OH- th s mol Ba(OH)2 l 0,15mol, nhng tnh theo Ba2+ th cn 0,20mol. thu lng kt ta ln nht cn tha mn iu kin kt ta ht Mg(OH)2, BaCO3 v BaSO4. Lng kt ta ln nht khi s mol Ba(OH)2= s mol Ba2+= 0,1.2=0,2mol

2( )

0,21Ba OH

V = =0,2 lt

b) Tnh pH: S mol OH- cn d l (0,2.0,2) -0,3 = 0,1mol

[OH-] = 0,11

= 0,1M = 10-1M [H+] = -14

11010

=10-13 hay pH = 13.


V d 2. Cho 500ml dung dch A cha cc ion Na+ 0,1mol, OH- 0,25mol, Cl- 0,15mol v a mol Ba2+. Hp th hon ton 4,48 lt CO2 ktc vo dung dch A th thu c bao nhiu gam mui khng tan, tch ra thnh kt ta?

Li gii

p dng LBTT ta c: 0,1 + 2a = 0,25 + 0,15 a = 0,15 (mol)

S mol CO2 = 4,4822,4

= 0,2mol; Ty theo s mol CO2 v OH- c th xy ra cc phng trnh

ha hc sau:

CO2 + 2OH- CO32- + H2O (1) xmol 2xmol xmol

CO2 + OH- HCO3- (2) ymol ymol

Ta c x + y = 0,2 (I) 2x + y = 0,25 (II) x = 0,05 v y = 0,15 S mol BaCO3 kt ta = 0,05mol, m = 0,05.197 = 9,85g. V d 3: Mt dung dch hn hp A c cha AlCl3 v FeCl3. Thm dung dch NaOH vo 100 ml dung dch A cho n d. Lc ly kt ta em nung nng n khi lng khng i c 2 gam cht rn. Mt khc phi dng ht vi 45 ml AgNO3 1,5M kt ta ht ion Cl- c trong 50 ml dung dch A. Tnh nng hai mui trong A?

Li gii

Gi s mol AlCl3 v FeCl3 ln lt l x v y mol (trong 100ml dung dch A) Al3+ Al(OH)3 AlO2- ; Fe3+ Fe(OH)3 Fe2O3 rn. x x x y y y/2

2 3Fe O

n = 0,0125 mol= y/2 y = 0,025 mol

Ag+ + Cl- AgCl

3x + 3y = 2.0,045.1,5 = 0,135 x = 0,02 mol.

Vy: [AlCl3] = 0,2M; [FeCl3] = 0,25M


V d 4. Ho tan a gam hn hp Na2CO3 v KHCO3 vo nc thu c 400 ml dung dch A. Cho t t 100 ml dung dch HCl 1,5 M vo dung dch A, thu c dung dch B v 1,008 lt kh (ktc). Cho B tc dng vi Ba(OH)2 d thu c 29,55 gam kt ta. Tnh a v nng mol ca cc ion trong dung dch A .

Li gii

nHCl = 1,5 x 0,1 = 0,15mol s mol H+ = 0,15; s mol CO2 = 1,00822,4

= 0,045mol

CO32- + H+ HCO3- (1) HCO3- + H+ CO2 + H2O (2)

0,045 0,045 0,045 Do Ba(OH)2 tc dng vi dung dch B thu c kt ta nn dung dch B c HCO3- d; S

mol kt ta BaCO3 = 29,55

197 = 0,15 (mol).

HCO3- + Ba2+ + OH- BaCO3 + H2O (3) 0,15 0,15

S mol H+ phn ng (1) = 0,15 0,045 = 0,105mol; Theo (1) s mol CO32- = 0,105 s mol Na2CO3 = 0,105 v s mol Na+ = 0,21 mol; S mol HCO3- sinh ra phn ng (1) = 0,105 mol. Tng s mol HCO3- = 0,045 + 0,15 = 0,195 mol,

S mol HCO3- c ban u = 0,195 - 0,105 = 0,09 mol

S mol KHCO3 = s mol K+ = 0,09 mol.

Vy a = 32CONam + 3KHCOm = (106 x 0,105) + (100 x 0,09) = 20,13 (gam)

Nng cc ion trong dung dch A:

[Na+] = 0,210,4

= 0,525M; [CO32-] = 0,1050, 4 = 0,263M;

[K+] = 0,090,4

= 0,225M; [HCO3-] = 0,090,4 = 0,225M


C. Bi tp n luyn Bi 1. Trong phng th nghim c cc dung dch b mt nhn: AlCl3, NaCl, KOH, Mg(NO3)2, Pb(NO3)2, Zn(NO3)2, AgNO3. Dng thm mt thuc th, hy nhn bit mi dung dch. Vit cc phng trnh phn ng (nu c). Bi 2. Trn 3 dung dch H2SO4 0,1M, HNO3 0,2M, HCl 0,3 M vi nhng th tch bng nhau thu c dung dch A. Ly 300ml dung dch A cho tc dng vi dung dch B gm NaOH 0,2M v KOH 0,29 M. Tnh th tch dung dch B cn dng sau khi tc dng vi 300ml dung dch A thu c dung dch c pH=2.

Bi 3. Nh t t tng git dung dch NaOH 2M vo 100ml dung dch X cha cc ion Zn2+, Fe3+, SO42- cho n khi kt ta hon ton ion Zn2+, Fe3+ th dng ht 350 ml. Tip tc thm dung dch NaOH 2M vo h trn cho n khi khi lng kt ta khng thay i th ht 200ml. Tnh CM ca mi mui trong dung dch X.

Bi 4. Thm m gam K vo 300 ml dung dch cha Ba(OH)2 0,1M v NaOH 0,1M thu c dung dch X . Cho t t 200 ml dung dch Al2(SO4)3 0,1M thu c kt ta Y . Xc nh gi tr ca m l thu c lng kt ta Y ln nht.

Bi 5. Cho 200 ml dung dch cha Fe2(SO4)3 0,3M v H2SO4 0,5M tc dng vi 100 ml dung dch NaOH 25% (d = 1,28 g/ml) thu c kt ta C v dung dch B. Nung C nhit cao n khi thu c cht rn c khi lng khng i.Vit cc PTP xy ra. Tnh khi lng cht rn thu c sau khi nung v nng mol ca cc ion trong dung dch B.

Bi 6. Cho 10,2g hn hp A gm Mg v Al tc dng vi dung dch HCl d ta thy c 11,2 lt kh H2 (ktc) thot ra v dung dch B. Thm t t V lt dung dch NaOH 0,5M th thu c lng kt ta ln nht c gi tr m gam.

1. Sau phn ng thu c bao nhiu gam mui clorua?

2. Tnh gi tr ca V v m?

Bi 7. Dung dch Xc cha cc ion Ca2+ , Al3+, Cl- . lm kt ta ht ion Cl- trong 10 ml dung dch phi dng ht 70 ml AgNO3 1M . Khi c cn 100 ml dung dch X thu c 35,55 gam mui khan. Tnh nng mol/l ca Ca2+ trong X.

Bi 8. Dung dch A cha cc ion Mg2+, Ca2+, HCO3- tc dng va vi 400 ml dung dch Ca(OH)2 1M . Sau phn ng ch thu c kt ta v H2O .Tnh khi lng mui ban u. Bi 9. Cho 100ml dung dch A gm NaOH 0,1M v Ba(OH)2 0,2M tc dng va vi V ml dung dch B cha HCl 0,1M v H2SO4 0,075 M, sau phn ng thu c m gam kt ta


trng. Lc b kt ta, c can dung dch th thu c m1 gam cht rn. Xc nh gi tr V ml, m (gam), m1 (gam). P N V HNG DN GII Bi 1. C th dng thm phenolphtalein nhn bit cc dung dch AlCl3, NaCl, KOH, Mg(NO3)2, Pb(NO3)2, Zn(NO3)2, AgNO3. Ln lt nh vi git phenolphtalein vo tng dung dch.

- Nhn ra dung dch KOH do xut hin mu hng.

Ln lt cho dung dch KOH vo mi dung dch cn li:

- Dung dch AgNO3 c kt ta mu nu

Ag+ + OH AgOH ; (hoc 2 Ag+ + 2 OH Ag2O + H2O) - Dung dch Mg(NO3)2 c kt ta trng, keo. Mg2+ + 2 OH Mg(OH)2 - Cc dung dch AlCl3, Pb(NO3)2, Zn(NO3)2 u c chung hin tng to ra kt ta trng, tan trong dung dch KOH (d).

Al3+ + 3 OH Al(OH)3 ; Al(OH)3 + OH Al(OH)4 Pb2+ + 2 OH Pb(OH)2 ; Pb(OH)2 + 2 OH Pb(OH)42 Zn2+ + 2 OH Zn(OH)2 ; Zn(OH)2 + 2 OH Zn(OH)42

- Dung dch NaCl khng c hin tng g

- Dng dung dch AgNO3 nhn ra dung dch AlCl3 do to ra kt ta trng

Ag+ + Cl AgCl - Dng dung dch NaCl nhn ra dung dch Pb(NO3)2 do to ra kt ta trng Pb2+ + 2 Cl PbCl2

- Cn li l dung dch Zn(NO3)2. Bi 2. Gi th tch dung dch B l V(lt) Th tch mi dung dch axit l: 300/3 = 100 ml

Tng s mol H+: (0,1.2 + 0,2 + 0,3).0,1 = 0,07 mol Tng s mol OH-: (0,2 + 0,29). V (mol)

H+ + OH- H2O (1) V pH = 2 mi trng axit nn trong phn ng (1) th H+

d, [H+] = 0,01M S mol H+ d = 0,07 - (0,2 + 0,29). V = 0,01.(0,3 + V) V = 0,08 lt.


Bi 3. Zn2+ + 2OH- Zn(OH)2 (1) ; Fe3+ + 3OH- Fe(OH)3 (2) x 2x x y 3y y (mol) Zn(OH)2 + 2OH- ZnO22- + H2O (3) x 2 x

2x + 3y = 0,35.2 = 0,7 v 2 x = 0,2.2 = 0,4

x = 0,2 mol; y = 0,1 mol. Vy CM (ZnSO4) = 2M; CM(Fe2(SO4)3) = 0,5M. Bi 4. Khi lng kt ta ln nht khi Al3+ kt ta hon ton.

Gi s mol K l x mol nOH- = 0,03 + 2.0,03 + x = 0,12 x = 0,03 mol

m= 1,17 gam.

Bi 5. S mol Fe2(SO4)3 = 0,3 x 0,2 = 0,06 s mol Fe3+ = 0,12; s mol SO42- = 0,18 S mol H2SO4 = 0,5 x 0,2 = 0,1 s mol H+ = 0,2; s mol SO42- = 0,1.

S mol NaOH = 40.100

28,1.100.25 = 0,8 s mol OH- = 0,8; s mol Na+ = 0,8.

H+ + OH- H2O ; Fe3+ + 3OH- Fe(OH)3 0,2 0,2mol 0,12 0,36 0,12mol

Tng s mol OH- phn ng = 0,2 + 0,36 = 0,56 s mol OH- d = 0,8 - 0,56 = 0,24

Kt ta C: Fe(OH)3. Dung dch B gm: SO42- (0,18 + 0,1 = 0,28mol), Na+ (0,8mol), OH- (0,24mol).

2Fe(OH)3 0t

Fe2O3 + 3H2O

0,12 0,06

Cht rn thu c l Fe2O3 c khi lng = 0,06 x 160 = 9,6g.

Bi 6. a) Cc phng trnh ha hc Mg + 2HCl MgCl2 + H2 (1) 2Al + 6HCl 2AlCl3 + 3H2 (2) p dng phng php bo ton khi lng mMui = mKim loi + mGc axit

S mol Cl- = 2 ln s mol H2 = 11,222,4

2= 1,0 mol; mMui = 10,2 + 35,5 = 45,7g.


a) Lng kt ta ln nht khi Mg2+ + 2OH- Mg(OH)2 (3); Al3+ + 3OH- Al(OH)3 (4) xmol 2xmol xmol ymol 3ymol ymol

Gii h: 24x + 27y = 10,2 (I) 2x + 3y = 1,0 (II) x = 0,2 v y = 0,2 m = 0,2(58 + 78)=27,2 (g)

V= 1,00,5

= 2lt; Nu lng NaOH ln hn s ha tan mt phn kt ta Al(OH)3.

Bi 7. Gi s mol CaCl2 v AlCl3 trong 10ml dung dch ln lt l x v y mol. S mol ion Cl-: 0,07 mol

2x + 3y = 0,0740x + 27y +0,07.35,5=3,555

x = 0,02 mol; y = 0,01 molCM(Ca2+) = 2M.

Bi 8. p s m = 30,8 gam . Bi 9. H+ + OH- H2O (1) ; Ba2+ + SO42- BaSO4 (2) Ta c: 0,1.0,5 = (0,1 + 0,15).V.10-3 V= 200ml m = 0,015.233= 3,495 gam; m1 = mNaCl + mBaCl2 =0,01.58,5 +0,005.208 = 1,625 gam.

D. Bi tp trc nghim Cu 1. Trn 200 ml dung dch NaOH 1M vi 250 ml dung dch cha ng thi NaHCO3 1M v BaCl2 xM thu c 31,52 gam kt ta. Xc nh x.

A. 0,6M B. 0,64 M C. 0,65M D. 0,55M. Cu 2. c php un nng c th nhn bit c bao nhiu dung dch mt nhn trong s cc dung dch sau: BaCl2 ; Ba(HCO3)2 ; NaHSO4 ; NaHCO3 ; NaHSO3, NaOH.

A. 2 B. 3 C. 4 D. 6

Cu 3. Phng trnh phn ng: Fe2(SO4)3 + 3Ba(OH)2 3BaSO4 + 2Fe(OH)3 c phng trnh ion thu gn l:

A. SO43- + Ba2+ BaSO4 B. Fe3+ + 3OH- Fe(OH)3 C. 2Fe3+ + 3Ba(OH)2 3Ba2+ + 2Fe(OH)3 D. 2Fe3+

+ 3SO43- +3Ba2+ + 6OH- 3BaSO4 + 2Fe(OH)3


Cu 4. Dung dch X cha Na2SO4 0,05M, NaCl 0,05M v KCl 0,1M. Phi dng hn hp mui no pha ch dung dch X:

A. KCl v Na2SO4 B. NaCl v K2SO4

C. KCl v NaHSO4 D. NaCl v KHSO4

Cu 5. Phng trnh ion rt gn sau: H+ + OH- H2O c phng trnh dng phn t l:

A. 3HNO3 + Fe(OH)3 Fe(NO3)3 + 3H2O B. 2HCl + Ba(OH)2 BaCl2 + 2H2O C. H2SO4 + Ba(OH)2 BaSO4 + 2H2O D. 2HNO3 + Cu(OH)2 Cu(NO3)2 + 2H2O

Cu 6(H,B-2009). Ho tan m gam hn hp gm Al, Fe vo dung dch H2SO4 long (d). Sau khi cc phn ngxy ra hon ton, thu c dung dch X. Cho dung dch Ba(OH)2 (d) vo dung dch X, thu c ktta Y. Nung Y trong khng kh n khi lng khng i, thu c cht rn Z l

A. hn hp gm BaSO4 v FeO B. hn hp gm Al2O3 v Fe2O3.

C. hn hp gm BaSO4 v Fe2O3. D. Fe2O3.

Cu 7. Cho cc cp dung dch sau: 1, BaCl2 v Na2CO3 2, NaOH v AlCl3 3, BaCl2 v NaHSO4

4, Ba(OH)2 v H2SO4 5, AlCl3 v K2CO3 6, Pb(NO3)2 v Na2S Trn cc dung dch trong tng cp vi nhau, nhng cp no xy ra phn ng?

A. 1,2,3,4,5,6 B. 1,2,4,5,6 C. 1,2,4,6. D. 1,2,4. Cu 8(2007- Khi B). Trong cc dung dch: HNO3, NaCl, Na2SO4, Ca(OH)2, KHSO4, Mg(NO3)2, dy gm cc cht u tc dng c vi dung dch Ba(HCO3)2 l:

A. HNO3, Ca(OH)2, KHSO4, Na2SO4. B. NaCl, Na2SO4, Ca(OH)2. C. HNO3, Ca(OH)2, KHSO4, Mg(NO3)2. D. HNO3, NaCl, Na2SO4.

Cu 9 (2009- Khi B). Cho cc phn ng ha hc sau: (1) (NH4)2SO4 + BaCl2 (2) CuSO4 + Ba(NO3)2 (3) Na2SO4 + BaCl2 (4) H2SO4 + BaSO3 (5) (NH4)2SO4 + Ba(OH)2 (6) Fe2(SO4)3 + Ba(NO3)2


Cc phn ng u c cng mt phng trnh ion rt gn l:

A. (1), (2), (3), (6). B. (1), (3), (5), (6). C. (2), (3), (4), (6). D. (3), (4), (5), (6). Cu 10. Cho s sau : Fe2(SO4)3 + X1 K2SO4 + ... Hy cho bit X1 c th l cht

A. KOH B. K2CO3 C. K D. KOH, K2CO3, K.

Cu 11. Dung dch X c cha Na+ 0,1 mol; Al3+ 0,15 mol ; Fe2+ 0,1mol; SO42- 0,2 mol v Cl- x mol. Hy la chn gi tr ng ca x.

A. x= 0,25 B. x = 0,35 C. x= 0, 45 D. x = 0,55 Cu 12. Dung dch X c cha Ba2+ 0,1 mol , Mg2+ 0,05 mol v Na+ 0,15 mol v anion A. OH- 0,45 mol B. Cl- 0,5 mol C. NO-3 0,45 mol D. SO42- 0,225 mol Cu 13. C cn dung dch X cha Al3+ 0,1 mol ; Cu2+ 0,1 mol ; SO42- 0,2 mol v ion Cl- th thu c bao nhiu gam mui khan ?

A. 28,3 gam B. 31,85 gam C. 34,5 gam D. 35,81gam. Cu 14. Dung dch A c a mol NH4+, b mol Mg2+, c mol SO42- v d mol HCO3-. Biu thc biu th ng s lin quan gia a, b, c, d l

A. a + b = c + d B. a + b = 2c + d

C. a + 2b = c + d D. a + 2b = 2c + d

Cu 15. Mt dung dch c cha 2 cation l Fe2+ (0,1 mol) v Al3+(0,2 mol)v 2 anion l Cl- (x mol) , SO42- (y mol). Khi c cn dung dch thu c 46,9 gam mui khan. Gi tr ca x v y ln lt l:

A. 0,3 v 0,2 B.0,2 v 0,3 C. 0,1 v 0,2 D. 0,2 v 0,1

Cu 16. Trong cc phn ng sau, phn ng no khng xy ra? A. KHCO3 + KOH K2CO3 + H2O

B. H2ZnO2 + 2NaOH Na2ZnO2 + 2H2O

C. Pb(NO3)2 + H2S PbS + 2HNO3. D. BaCl2 + SO2 + H2O BaSO3 + 2HCl


Cu 17. Trn dung dch cha Ba2+; OH- 0,06 mol v Na+ 0,02 mol vi dung dch cha HCO-3 0,04mol ; CO2-3 0,03 mol v Na+ . Hy cho bit khi lng kt ta thu c sau phn ng.

A. 3,94 gam B. 5,91 gam C. 7,88 gam D. 9,85gam. Cu 18. Mt dung dch X gm NaHCO3, Na2CO3. Cho t t tng git dung dch HCl vo dung dch X cho n khi bt u c kh thot ra th dng li thu c dung dch Y. trong dung dch Y cha cc cht sau:

A. Na2CO3 v NaHCO3 B. NaHCO3 v NaCl

C. Na2CO3; NaHCO3 v NaCl. D. HCl v NaCl.

Cu 19. Cho 0,1 mol Ba vo 1lt dung dch cha HCl 0,1M, FeCl2 0,1M v Na2SO4 0,1M. Hy cho bit khi lng kt ta thu c sau phn ng ?

A. 23,3 gam B. 9 gam C. 32,3 gam D. 27,8 gam

Cu 20: Hn hp X cha Na2O, NH4Cl, NaHCO3 v BaCl2 c s mol mi cht u bng nhau. Cho hn hp X vo H2O (d), un nng, dung dch thu c cha A. NaCl, NaOH, BaCl2. B. NaCl, NaOH.

C. NaCl, NaHCO3, NH4Cl, BaCl2. D. NaCl.

P N V HNG DN GII 1.B 2.D 3.D 4.B 5.B 6.C 7.B 8.B 9.A 10.A

11.B 12.C 13.B 14.D 15.B 16.A 17.A 18.B 19.D 20.D

Cu1. 3HCO + OH 2H O + 23CO ; 2Ba + + 23CO 3BaCO

0,25 > 0,2 0,2; 0,16 0,16 0,16

2 0,16Ban + = x =0,16 0,640,25

M= B

Cu 8. Ba(OH)2 + 2HNO3 Ba(NO3)2 + 2H2O + 2CO2 Ba(HCO3)2 + Ca(OH)2 BaCO3 + CaCO3 + H2O Ba(HCO3)2 + 2KHSO4 BaSO4 + 2 H2O + 2CO2 + K2SO4 Ba(HCO3)2 + Na2SO4 BaSO4 + 2NaHCO3


Cu 10. Fe2(SO4)3 + X1 K2SO4 V tri ch c 2 cht l Fe2(SO4)3 v X1 X1 l KOH v K2CO3 + Fe2(SO4)3 + H2O K2SO4 +... 6K + Fe2(SO4)3 + 6H2O 2Fe(OH)2 + 3H2 + 3K2SO4 Cu 15.Theo bo ton ion: 0,1.2 + 0,2.3=x.1 +2.y x+2y=0,8 (1) Tng mmui :46,9 = 56.0,1 + 27.0,2 +35,5.x + 96.y 35,5x + 96y = 35,9 (2) Gii h (1) ; (2) x = 0,2 mol; y = 0,3 mol (B) Cu 19. Ba + 2 H2O Ba(OH)2 + H2 (1) 0,1 0,1 0,1

H+ + OH- H2O (2) 0,1 0,1

2OH- + Fe2+ Fe(OH)3 (3) 0,1 0,05

Ba2+ + SO42- Ba(SO4)2 (4) 0,1 0,1 0,1

m = 0,05.90 + 233.0,1 = 27,8 (D) Cu 20. Na2O + H2O 2NaOH a 2a

NaOH + NH4Cl NaCl + NH3 + H2O

a a

NaOH + NaHCO3 Na2CO3 + H2O

a a a

Na2CO3 + BaCl2 BaCO3 + 2NaCl

a a

NaOH ht , Na2CO3 c tao ra ri phn ng ht , BaCO3 l cht kt ta , NH3 l kh

Cht cn li trong dung dch sau phn ng l NaCl. Chn D


4. MT S T KIM TRA KIM TRA S 1

Thi gian 45 pht Cu 1. Trong cc phn ng di y, phn ng no trong nc ng vai tr l mt axit Bronstet

A. AlO2- + 2H2O Al(OH)3 + OH- B. HCO3- + H2O H3O+ + CO32-

C.CuSO4 + 5H2O CuSO4.5H2O D. HNO3 + H2O H3O+ + NO3- Cu 2. Khi trn ln tng cp dung dch cc cht sau:Na2CO3, CuSO4, Ca(NO3)2, FeCl3, Al(NO3)3, KOH, s cp cht c phn ng vi nhau l: A.7 B.8 C.6 D.9

Cu 3. (2007_khi A): Cho dy cc cht: Ca(HCO3)2, NH4Cl, (NH4)2CO3, ZnSO4, Al(OH)3, Zn(OH)2. S cht trong dy c tnh cht lng tnh l A. 3. B.4. C. 2. D. 5. Cu 4. Cho cc phn ng sau :

(1) CuCl2 + H2S CuS + 2HCl (2) Fe + 2HCl FeCl2 + H2 (3) Al + 4HNO3 Al(NO3)3 + NO + 2H2O (4) CaCO3 + 2H+ Ca2+ + H2O + CO2 (5) CuCl2 + 2NaOH Cu(OH)2 + 2NaCl Nhng phn ng trao i ion l:

A. (1) , (2) , (5) B. (2) , (3) , (5) C. (3) , (4) , (5) D. (1) , (4) , (5) Cu 5. Cho cc cp dung dch sau: 1, BaCl2 v Na2CO3 2, NaOH v AlCl3 3, Pb(NO3)2 v Na2S 4, Ba(OH)2 v H2SO4 5, AlCl3 v K2CO3 6, BaCl2 v NaHSO4 Trn cc dung dch trong tng cp vi nhau, nhng cp xy ra phn ng l

A. 1,2,3,4,5 B. 1,2,4,5,6 C. 1,2,3,4,6. D. 1,2,4,5. Cu 6. Cho cc phn ng sau: (1)CaCO3 + H2SO4 = CaSO4 + H2O + CO2


(2)Ca(HCO3)2 + NaHSO4 = CaSO4 + NaHCO3 + CO2 + H2O (3)Ba(HCO3)2 + 2NaHSO4 = BaSO4 + Na2SO4 + 2CO2 + 2H2O (4)3NH3 + AlCl3 + 3H2O = Al(OH)3 + 3NH4Cl Trong cc phn ng trn, phn ng no khng phi phn ng axit- baz A.(1) B.(2) C.(3) D.(4) Cu 7. Cho dung dch NaHCO3 vo cc dung dch sau : FeCl3, NaOH, BaCl2 v NaHSO4. Hy cho bit dung dch no khng c phn ng xy ra ? A. NaOH B. NaHSO4 C. FeCl3. D. BaCl2 .

Cu 8 (2007_khi A): Nh t t cho n d dung dch NaOH vo dung dch AlCl3. Hin tng xy ra l

A. Ch c kt ta keo trng.

B. Khng c kt ta, c kh bay ln.

C. C kt ta keo trng , sau kt ta tan.

D. C kt ta keo trng v c kh bay ln.

Cu 9. Cho cc kt lun sau : (1) mui axit l nhng cht m anion gc axit c kh nng cho proton. (2) mui m anion gc axit c cha H u l cc mui axit. (3) mui c kh nng cho proton u l mui axit. (4) mui axit khi tan vo nc to mi trng axit. Hy cho bit nhng kt lun no ng ?

A. (1) (2) (3) (4) B. (1) (2) (4) C. (1) (3) D. (1) Cu 10. Cho cc cp cht (hoc dd) sau y: (1) dd Fe (NO3)3 + dd NaI; (2) dd FeCl3 + dd Na2CO3 ; (3) Al + dd NaOH ; (4) dd AlCl3 + dd NaOH; (5) dd NH3 + dung dch FeCl3; (6) dd NH4Cl + dd NaAlO2 (t0); (7) dd Na2CO3 + dd FeCl2. Hy cho bit c bao nhiu cp cht khi phn ng to ra sn phm kh.

A 4 B. 5 C. 3 D. 2 Cu 11. Thm 15ml dung dch NaOH 1M vo 15ml dung dch HCl cha bit nng th thu c 30ml dung dch c pH = 7. Nng ca dung dch HCl ban u l:


A. 1M B. 1,5M C. 2M D. 2,5M Cu 12 (2007_khi A): Cho m gam hn hp Mg, Al vo 250 ml dung dch X cha hn hp axit HCl 1M v axit H2SO4 0,5M, thu c 5,32 lt H2 ( ktc) v dung dch Y (coi th tch dung dch khng i). Dung dch Y c pH l A. 1. B. 7. C. 2. D. 6. Cu 13. Cho cc cht sau : Na2SO4, Na2CO3, NaCl, H2SO4, BaCl2, NaOH. Ch dng thm cht no di y phn bit c cc cht trn

A. qu tm B. dung dch HCl

C. dung dch NaOH D. dung dch Ba(OH)2 Cu 14. Cho dung dch Ba(OH)2 d vo 100 ml dung dch cha Fe2+ 0,5M, SO42- a M v Na+ 0,4M. Sau khi phn ng hon ton thu c bao nhiu gam kt ta ?

A. 4,5 gam B. 16,31 gam C. 5,35 gam D. 20,81 gam Cu 15. Cho rt t t tng git 100 ml dung dch HCl 2M vo dung dch cha Na2CO3 0,1 mol v NaHCO3 0,15 mol. Th tch kh CO2 thot ra (ktc) l A. 2,24 lt. B. 2,8 lt. C. 3,92 lt D. 4,48 lt. Cu 16. Cho 2,4 gam Mg vo 200 ml dung dch H2SO4 0,75M thu c dung dch A. Cho 200 ml dung dch B cha Ba(OH)2 0,3M v NaOH 0,5M vo dung dch A th thu c khi lng kt ta l

A. 3,48 gam B. 13,98 gam C. 17,45 gam D. 19,78 gam Cu 17. Trn 100 ml dung dch cha CaCl2 0,4M v BaCl2 0,2M vi 200 ml dung dch cha K2CO3 0,3M v Na2CO3 0,1M. Khi lng kt ta thu c l:

A. 4 gam B. 7,94 gam C. 15,76 gam D. 15,88gam. Cu 18. Cho 4 phn ng: (1) Fe + 2HCl FeCl2 + H2 (2) 2NaOH + (NH4)2SO4 Na2SO4 + 2NH3 + 2H2O (3) BaCl2 + Na2CO3 BaCO3 + 2NaCl (4) 2NH3 + 2H2O + FeSO4 Fe(OH)2 + (NH4)2SO4 Cc phn ng thuc loi phn ng axit - baz l

A. (2), (4). B. (3), (4). C. (2), (3). D. (1), (2).


Cu 19. Cho cc dung dch sau: Na2S, FeSO4, BaCl2, NH4NO3, NaHSO4, Na2CO3 v CH3COONa.Hy cho bit dung dch no c pH > 7

A. Na2S, FeSO4, BaCl2, NH4NO3, NaHSO4, Na2CO3 v CH3COONa.

B. Na2S, NH4NO3, NaHSO4, Na2CO3 .

C. Na2S, Na2CO3 v CH3COONa

D. Na2S, NH4NO3, Na2CO3 v CH3COONa.

Cu 20. Tp hp nhng ion no sau y u th hin tnh baz: A. Al3+, HS- , SO32-, HPO42- B. CO32-, S2- , PO43- , OH-

C. HSO4- , Cl - , CH3COO - , PO43- D. SO42-, HSO-4 , NO-3 , NH+4

Cu 21. Cho 11,15 gam hn hp X gm Na v Al vo nc d thy tan hon ton thu c 9,52 lt kh H2 (ktc) v dung dch Y. Khi thm 200 ml dung dch HCl 1M vo dung dch Y th thu c khi lng kt ta l

A. 10,92 gam B. 11,31 gam C. 12,48 gam D. 11,7 gam Cu 22. Trong cc dung dch: HNO3, NaCl, Na2SO4, Ca(OH)2, KHSO4, Mg(NO3)2, dy gm cc cht u tc dng c vi dung dch Ba(HCO3)2 l: A. HNO3, NaCl, Na2SO4. B. HNO3, Ca(OH)2, KHSO4, Na2SO4. C. NaCl, Na2SO4, Ca(OH)2. D. HNO3, Ca(OH)2, KHSO4, Mg(NO3)2. Cu 23 (2007_khi A). C 4 dung dch mui ring bit: CuCl2, ZnCl2, FeCl3, AlCl3. Nu thm dung dch KOH (d) ri thm tip dung dch NH3 (d) vo bn dung dch th s cht kt ta thu c l

A. 3. B. 2. C. 4. D. 1.

Cu 24. Cho 40 ml dung dch HCl 0,85M vo 160 ml dung dch cha ng thi Ba(OH)2 0,08M v KOH 0,04M. Dung dch thu c c pH l:

A. 2 B. 7 C. 12 D. 8.

Cu 25. Dung dch X cha HCl v HNO3 pH=1 ; dung dch Y cha Ba(OH)2 0,04M v NaOH 0,02M. Trn 2 dung dch trn vi nhau theo t l no th thu c dung dch c pH = 7.

A. VX /VY = 1 B. VX /VY = 2 C. VX /VY = 1/2 D. VX /VY = 3

Cu 26. Cho cc dung dch trong dung mi l nc, c cng nng 0,1M sau: X1: NH4Cl ; X2: CH3COONa ; X3: Na2CO3 ; X4: NaHSO4 ; X5 : NaCl


Cc dung dch c pH ln hn 7 l:

A. X1, X3, X4, X5 B. X2, X3 C. X1, X4, X5 D. X2, X3, X4

Cu 27. Trn 200 ml dung dch NaOH 1,5M vi 150 ml dung dch H2SO4 aM thu c dung dch X c th ho tan va ht 2,34 gam Al(OH)3 . Tnh a = ? A. 1,5M hoc 1,8M B. 0,9M C. 1,8M D. 1,5M hoc 0,9M Cu 28. Trn 100 ml dung dch (gm Ba(OH)2 0,1M v NaOH 0,1M) vi 400 ml dung dch (gm H2SO4 0,0375M v HCl 0,0125M), thu c dung dch X. Gi tr pH ca dung dch X l

A. 7. B. 2. C. 1. D. 6.

Cu 29. Cho cc dung dch cng nng mol/lt: KHS, NaOH, K2CO3,Ca(OH)2, NaCl. Hy sp xp cc dung dch theo chiu pH ca dung dch tng dn

A. NaCl

V = 2,24 lt A

Cu 16. Mg + H2SO4 MgSO4 + H2 (1) 0,1 0,1 0,1

2 4H SOn d = 0,05 mol

H+ + OH- H2O (2) 0,05.2 OHn d (sau p 2)= 0,2(2.0,3+0,5)-0,05.2 = 0,12 mol Mg2+ + 2OH- Mg(OH)2 bd 0,1 0,12 0,06

2( )Mg OHm = 3,48 g p 0,06 0,12 0,06

Ba2+ + SO42- BaSO4

0,06 0,1 0,06 4BaSO

m = 13,98 m = 17,46 C

Cu 18. Phn ng axit l phn ng trong c s cho v nhn proton H+ Cc phn ng (2) , (4) . (2) 2NaOH + (NH4)2SO4 Na2SO4 + 2NH3 + 2H2O Bazo Axit

(4) 2NH3 + 2H2O + FeSO4 Fe(OH)2 + (NH4)2SO4 Baz Axit

Chn A

Cu 22. 2HNO3 + Ba(HCO3)2 Ba(NO3)2 + CO2 + 2H2O Na2SO4 + Ba(HCO3)2 BaSO4 + 2NaHCO3 Ca(OH)2 + Ba(HCO3)2 BaCO3 + CaCO3 + H2O KHSO4 + Ba(HCO3)2 BaSO4 + 2CO2 + 2H2O Chn B

NaCl + Ba(HCO3)2 Khng phn ng v NaHCO3 , BaCl2 khng kt ta . Mg(NO3)2 + Ba(HCO3)2 Khng phn ng v Mg(HCO3)2 tan , Ba(NO3)2 tan Cu 23. Thm KOH

(d):

Cu2+ + 2OH- Cu(OH)2 ; Zn2+ + 4OH- ZnO22- + 2H2O Fe3+ + 3OH- Fe(OH)3 ; Al3+ + 4OH- AlO2- + 2H2O


s thu c l : Cu(OH)2 ; Fe(OH)3 Thm NH3 d : Cu(OH)2 + 4NH3 Cu(NH3)4(OH)2 Vy cn li l Fe(OH)3 D Cu 27. OH- + H+ H2O (1) +) TH1: p (1) d OH- : OHn d = 0,2.1,5 2.a.0,15 = 0,3 0,3a (mol) OH- + Al(OH)3 AlO2- + 2H2O 0,03 0,03 OHn = 0,03 0,3 0,3a = 0,03 a = 0,9 M

+)TH2: p (1) d H+ : H

n + d = 2a.0,15 0,2.1,5 = 0,3a -0,3

3H+ + Al(OH)3 Al3+ + 3H2O 0,09 0,03

Hn + = 0,09 0,3a 0,3 = 0,09 a = 1,3 M

Vy chn p n D.

Cu 28. n Ba(OH)2 = 0,1.0,1 = 0,01 mol , n NaOH = 0,1.0,1 = 0,01 mol , n H2SO4 = 0,4.0,0375 = 0,015 mol , n HCl =0,0125.0,4 = 0,025 mol

Ba(OH)2 Ba2+ + 2OH- ; NaOH Na+ + OH- 0,01 0,02 ; 0,01 0,01

Tng s mol OH- : 0,02 + 0,01 = 0,03 mol

H2SO4 2H+ + SO42- ; HCl H+ + Cl-

0,015 0,03 ; 0,005 0,005

Tng s mol ca H+ : 0,035 mol

Phn ng : H+ + OH- H2O

Ban u 0,035 0,03 Phn ng 0,03 0,03

Kt thc 0,005 0

Sau phn ng d 0,005 mol H+ , Tng th tch l 0,5 lit

[H+] = 0,005/0,05 = 0,01 PH = -Lg[H+] = -lg0,01 = 2 Chn B


KIM TRA S 2 Thi gian 45 pht

Cu 1. Cn bng sau tn ti trong dung dch: CH3COOH CH3COO- + H+

nhit khng i, in li ca CH3COOH s bin i nh th no khi pha long dung dch?

A. tng B. gim C. khng i D. tng sau gim.

Cu 2. Dy cht no di y gm tt c cc mui u b thy phn khi tan trong nc? A. Na3PO4, FeCl2, KNO3 B. Mg(NO3)2, BaCl2, NaNO2 C. AlCl3, Na3PO4, K2SO3 D. K2S, Na2SO4, K3PO4.

Cu 3. Kt qu phn tch cho thy mt dung dch c [OH-] = 10-3 M th mi trng ca dung dch l:

A. Baz B. Lng tnh C. Trung tnh D. Axit

Cu 4 (2007_khi A): nhn bit 3 axit c, ngui: HCl, H2SO4, HNO3 ng ring bit trong 3 l mt nhn, ta dng thuc th l

A. Al. B. Fe. C.CuO. D. Cu.

Cu 5. Cho 4,6 gam Na vo 100 ml dung dch HCl aM thu c dung dch A. Cho dung dch A vo 100 ml dung dch AlCl3 0,8M th thu oc 0,78 gam kt ta. Tnh a

A. 1,1M B. 1,7M C. 2,4M D. 2M.

Cu 6 (2007_khi A): Trn dung dch cha a mol AlCl3 vi dung dch cha bmol NaOH. thu c kt ta th cn c t l

A. a : b =1 : 5. B. a: b > 1 : 4. C. a : b = 1: 4. D. a :b < 1: 4. Cu 7. Cho dung dch cha cc ion: Na+, Ca2+, H+, Cl-, Ba2+, Mg2+. Nu khng a ion l vo dung dch, dng cht no sau y tch nhiu ion nht ra khi dung dch?

A. dung dch Na2SO4 va . B. dung dch NaOH va .

C. dung dch Na2S va . D. dung dch Na2CO3 va .

Cu 8(2007_khi A): Ho tan hon ton 2,81gam hn hp gm Fe2O3, MgO, ZnO trong 500ml axit H2SO4 0,1M (va ). Sau phn ng, hn hp mui sunfat khan thu c khi c cn dung dch c khi lng l

A. 6,81 gam. B. 4,81 gam. C. 3,81 gam. D. 5,81 gam


Cu 9. Tp hp cc ion no sau y th hin tnh cht baz : A. CO32-, S2-, PO43-, CH3COO- B.Fe3+,S2-, SO32-, OH-

C. HSO4-,Br-,CH3COO-,PO43- D.SO42-, HS-,NO-3,OH-

Cu 10. Dung dch thu c khi trn ln 200 ml dung dch NaCl 0,2M v 300 ml dung dch Na2SO4 0,2M c nng [Na+] l A. 0,23M B. 32M C. 0,2M D. 0,1M

Cu 11. Trn dung dch cha Ba2+; OH- 0,06 mol v Na+ 0,02 mol vi dung dch cha HCO-

3 0,04mol ; CO2-3 0,03 mol v Na+ . Hy cho bit khi lng kt ta thu c sau phn ng.

A. 3,94 gam B. 5,91 gam C. 7,88 gam D. 9,85gam. Cu 12. Cc cht no va tc dng vi dung dch HCl va tc dng vi dung dch NaOH?

A. Pb(OH)2, ZnO, Fe2O3 B. Al(OH)3, Al2O3, Na2CO3 C. Na2SO4, HNO3, Al2O3 D. Na2HPO4, ZnO, Zn(OH)2

Cu 13(H,2009-A). X l dung dch AlCl3, Y l dung dch NaOH 2M. Thm 250 ml dung dch Y vo cc cha 100 ml dd X, khuy u th trong cc to ra 10,92 gam kt ta. Cc phn ng u xy ra hon ton. Hy xc nh nng mol ca dung dch X.

A. 1,4M B. 1,6M C. 1,8M D. 1,5M Cu 14. Cho dy cc cht: KHCO3, Pb(OH)2, NH4NO3, CH3COONa, (NH4)2CO3, AlCl3, ZnO, Al(OH)3. S cht trong dy c tnh cht lng tnh l A. 5 B.6 C.7 D.4 Cu 15 (2009- Khi B). Trn 100 ml dung dch hn hp gm H2SO4 0,05M v HCl 0,1M vi 100 ml dung dch hn hp gm NaOH 0,2M v Ba(OH)2 0,1M, thu c dung dch X. Dung dch X c pH l

A. 13,0. B. 1,2 C. 1,0. D. 12,8.

Cu 16. Dung dch A cha a mol NH4+ , b mol Na+, c mol SO42-, d mol HCO3- v e mol CO32- khng k cc ion H+ v OH- ca nc). Thm (c+d+e) mol Ba(OH)2 vo dung dch A, un nng thu c kt ta B, dung dch X v kh Y duy nht c mi khai. S mol mi cht trong kt ta B l:

A. c mol BaSO4, (e+d) mol BaCO3. B. (e+d) mol BaCO3. C. (c+d) mol BaSO4. D. e mol BaSO4, (c+d) mol BaCO3.


Cu 17 (H, C Khi A2004). Cho 40ml dung dch HCl 0,75M vo 160ml dung dch cha ng thi Ba(OH)2 0,08M v KOH 0,04M. (cho bit [H+].[OH-] = 10-14). Gi tr pH ca dung dch thu c l:

A. 10. B. 11. C. 12. D. 13.

Cu 18 (H SPHN-2001). Th tch dung dch Ba(OH)2 0,025M cn cho vo 100ml dung dch gm HNO3 v HCl c pH = 1,0 pH ca hn hp thu c bng 2,0 l:

A. 110 ml. B. 150 ml. C. 250 ml. D. 200 ml. Cu 19. Nhng mu giy qu tm vo dung dch CH3COOH long, qu chuyn mu hng. Mu hng ca qu m dn ln trong trng hp no sau y?

A. un nng B. Thm Na2CO3

C. Thm NH4Cl D. Thm NaCl

Cu 20(H,2007-B) Trong cc dung dch: HNO3, NaCl, Na2SO4, Ca(OH)2, KHSO4, Mg(NO3)2, dy gm cc cht u tc dng c vi dung dch Ba(HCO3)2 l: A. HNO3, NaCl, Na2SO4. B. HNO3, Ca(OH)2, KHSO4, Na2SO4. C. NaCl, Na2SO4, Ca(OH)2. D. HNO3, Ca(OH)2, KHSO4, Mg(NO3)2. Cu 21. C bn l mt nhn ng bn dung dch: HCl, H2SO4, Na2CO3, BaCl2. Thuc th no sau y c th nhn bit c c bn dung dch trn:

A. Dung dch NH3. B. Qu tm. C. Dung dch NaCl. D. Dung dch NaOH.

Cu 22(H,2009-A). Cho 3,68 gam hn hp gm Al v Zn tc dng vi mt lng va dung dch H2SO4 10%, thu c 2,24 lt kh H2 ( ktc). Khi lng dung dch thu c sau phn ng l

A. 101,48 gam. B. 101,68 gam. C. 88,20 gam. D. 97,80 gam. Cu 23. Cn trn dung dch X cha HCl 0,1M v H2SO4 0,1M vi dung dch Y cha NaOH 0,3M v Ba(OH)2 0,1M theo t l th tch nh th no thu c dung dch c pH = 13? A. VX/VY = 1/1 B. VX/VY = 1/2 C. VX/VY = 1/3 D. VX/VY = 3/1

Cu 24(H,2007-B). Cho 200 ml dung dch AlCl3 1,5M tc dng vi V lt dung dch NaOH 0,5M, lng kt ta thu c l 15,6 gam. Gi tr ln nht ca V l

A. 1,2. B. 1,8. C. 2,4. D. 2.

Cu 25. Cho cc dung dch Ba(NO3)2; Al2(SO4)3; ZnCl2; Mg(NO3)2; CuSO4; FeCl3. nhn bit c cc dung dch trn c th dng thuc th l dung dch


A. Ca(OH)2. B. KOH. C. H2S. D. NH3. Cu 26. Ch s dng mt ho cht no sau y c th phn bit c cc dung dch mt nhn sau bng phng php ho hc: NaCl ; AlCl3 ; NaAlO2 ; Na2CO3; Na2S?

A. H2O. B. qu tm.

C. Dung dch HCl. D. Dung dch NaOH.

Cu 27. Mui trung ho l A. Mui khng cn hiro c kh nng thay th bi kim loi.

B. Mui m dung dch c pH = 7

C. Mui khng cn c hiro trong phn t

D. Mui khng c kh nng phn ng vi axit v baz.

Cu 28(H,2009-A). Dy gm cc cht u tc dng c vi dung dch HCl long l: A. AgNO3, (NH4)2CO3, CuS. B. FeS, BaSO4, KOH. C. Mg(HCO3)2, HCOONa, CuO. D. KNO3, CaCO3, Fe(OH)3.

Cu 29(H,2009-A). Cho bn hn hp, mi hn hp gm hai cht rn c s mol bng nhau: Na2O v Al2O3; Cu v FeCl3; BaCl2 v CuSO4; Ba v NaHCO3. S hn hp c th tan hon ton trong nc (d) ch to ra dung dch l A. 1. B. 3. C. 2. D. 4.

Cu 30. Nng OH- ca dung dch NH4OH 0,1M c 1% baz b phn li l: A. 10-2M B. 10-3 M C. 10-4 M D. 10-1 M.

p n v hng dn gii

1.A 2.C 3.A 4.D 5.B 6.B 7.D 8.A 9.A 10.D

11.D 12.D 13.B 14.A 15.C 16.A 17.C 18.B 19.C 20.B

21.B 22.A 23.A 24.D 25.D 26.C 27.A 28.C 29.A 30.B

Cu 6. AlCl3 + 3NaOH Al(OH)3 + 3NaCl (1) a 3a a

NaOH + Al(OH)3 NaAlO2 + 2H2O (2) a a


NaOHn = 4a = b. thu c th NaOHn

Cu 22. 2H+ H2

0,2 0,1 H

n + = 0,2 2 4H SOn = 0,1 m = 9,8(g)

mdd =98(g); mdd = mkloai +mH2SO4- 2Hm = 3,68 + 98 -0,1.2 =101,48 chn A.

Cu 24. n AlCl3 = 0,2.1,5 = 0,3 mol , S mol kt ta n Al(OH)3 = 15,6/78 = 0,2 mol * Trng hp 1 : Ch c 1 phn ng sau (sau phn ng (1) NaOH ht ) : AlCl3 + 3NaOH Al(OH)3 + 3NaCl Ban u 0,3 mol 0,6

Phn ng 0,2 0,6 0,2 Kt thc 0,1 0 0,2

n AlCl3 phn ng = 0,2 AlCl3 d = 0,3 0,2 = 0,1 mol

n NaOH phn ng = 0,6 mol V NaOH = 0,6/0,5 = 1,2 lt

* Trng hp 2 : C c hai phn ng (trong phn ng (1) NaOH d , AlCl3 ht ) : AlCl3 + 3NaOH Al(OH)3 + 3NaCl (1); Al(OH)3 + NaOH NaAlO2 + H2O (2) 0,3 0,9 0,3 ; x x

Sau (1) , (2) thu c 0,2 mol cht kt ta 0,3 x = 0,2 x = 0,1 mol tng s mol NaOH tham gia phn ng l : 0,9 + 0,1 = 1 mol V = 1/0,5 = 2 lt Chn D.

Cu 28. Chn p n C Mg(HCO3)2 + 2HCl MgCl2 + 2H2O + 2CO2. HCOONa + HCl HCOOH + NaCl

CuO + 2HCl CuCl2 + H2O

Cu 29. 1) Na2O + H2O 2NaOH; 2NaOH + Al2O3 2NaAlO2 + H2O. 2) Cu + 2FeCl3 CuCl2 + 2FeCl2 d Cu loi 3) BaCl2 + CuSO4 loi 4) Ba + 2H2O Ba(OH)2 + H2 ; Ba(OH)2 + 2NaHCO3 BaCO3 + Na2CO3 + 2H2O loi Vy c 1 hn hp tha mn Chn p n A


CHNG 2. NHM NIT 1. NIT V HP CHT CA NIT A. Hng dn t n tp l thuyt I. KHI QUT V NHM NIT

Nhm nit gm cc nguyn t N, P, As, Sb, Bi. Chng u thuc nguyn t p v nhm VA.

I.1. S bin i tnh cht ca cc n cht Trong iu kin thng, nit l cht kh, cc n cht cn li l cht rn.

Trong cc hp cht cc nguyn t nhm nit c s oxi ho cao nht l +5, ngoi ra cn c cc s oxi ho +3 v 3. Ring N cn c thm cc s oxi ho +1, +2, +4.

Cc nguyn t nhm nit c th th hin c tnh oxi ho v tnh kh v kh nng oxi ho gim dn t nit n bitmut.

I.2. S bin i tnh cht ca cc hp cht Hirua ca cc nguyn t nhm nit c cng thc chung RH3 vi bn nhit gim

dn t NH3 n BiH3. Dung dch ca nhng cht ny trong nc c tnh baz.

T nit n bitmut, tnh axit ca cc oxit v hiroxit tng ng gim dn ng thi tnh baz tng dn.

II. NIT V HP CHT CA NIT II.1. Nit

Tnh cht: C cng thc cu to N N. Do phn t c lin kt 3 nn iu kin thng kh tr v mt ho hc (ch tc dng vi Li). nhit cao n hot ng hn do N c m in kh ln v th hin tnh oxi ho tri hn tnh kh.

+ Tnh oxi ho: N2 + 3H2 2NH3 N2 + 6Li 2Li3N

+ Tnh kh: N2 + O2 2NO

Ngay iu kin thng, NO kt hp vi O2 (khng kh) NO2 mu nu iu ch:

+ Trong phng th nghim: NH4NO2 0t

N2 + 2H2O

+ Trong cng nghip: Chng ct phn on khng kh lng.

xt, 400oC

3000oC


II.2. Amoniac v mui amoni a. Amoniac

Tnh cht l ho: l cht kh khng mu, mi khai v xc, tan nhiu trong nc. + Tnh baz yu: NH3 + H2O NH4+ + OH Kb = 1,8.105

Do NH3 lm xanh giy qu m

NH3 + H+ NH4+

Al3+ + 3NH3 + 3H2O Al(OH)3 + 3NH4+ + Kh nng to phc: Cu(OH)2 + 4 NH3 [Cu(NH3)4](OH)2 AgCl + 2 NH3 [Ag(NH3)2]Cl + Tnh kh: 4NH3 + 3O2 2N2 + 6H2O

4NH3 + 5O2 (kk) 0850 C,Pt

4NO + 6H2O

2NH3 + 3Cl2 N2 + 6HCl

(sn phm sinh ra khi trng l do kh HCl va to thnh ho hp vi NH3) 3CuO + 2NH3

0t 3Cu + N2 + 3H2O

iu ch:

+ Trong phng th nghim: 2NH4Cl + Ca(OH)2 2 NH3 + CaCl2 + 2H2O + Trong cng nghip: N2 + 3H2 2NH3 b. Mui amoni: Tt c cc mui amoni u tan trong nc v khi tan in li hon ton

thnh cc ion.

+ Phn ng trao i ion:

NH4Cl + NaOH NaCl + NH3 + H2O (phn ng nhn bit mui amoni) Hay: NH4+ + OH NH3 + H2O + Phn ng nhit phn: NH4Cl NH3 + HCl ; NH4NO3 N2O + 2H2O

II.3. Axit nitric v mui nitrat a. Axit nitric

Tnh cht vt l: l cht lng, bc khi mnh trong khng kh, khi un nng n b phn hu mt phn theo phng trnh: 4HNO3 4NO2 + O2 + 2H2O

- Tnh cht ha hc

to

Fe, to

to


+ Tnh axit mnh: Mang y tnh cht chung ca mt axit.

Lu : HNO3 tc dng vi kim loi khng gii phng H2. + Tnh oxi ho mnh: Tu thuc vo nng axit v v bn cht ca cht kh m HNO3

c th b kh n mt s sn phm khc nhau ca nit nh:

+ Dung dch HNO3 c c th oxi ho hu ht kim loi (tr Pt, Au) nhit thng, hoc Fe, Al, Cr nhit cao, trong N+5 chuyn thnh N+4 (NO2).

+ Vi kim loi yu th HNO3 c to thnh NO2, cn long cho sn phm NO.

+ Vi kim loi mnh HNO3 long c th b kh n N+, N0 hoc N3.

+ Dung dch HNO3 c, ngui lm th ng ho mt s kim loi nh Al, Fe, Cr...Ngoi ra dung dch HNO3 c cn oxi ho c mt s phi kim nh C, S v nhiu hp cht v c v hu c khc.

+ Dung dch HNO3 c khng bn, nhit cao hoc khi c nh sng, mt phn axit HNO3 b phn hu to thnh NO2, O2 v nc.

4HNO3 c 4NO2 + O2 + 2H2O

iu ch:

+ Trong PTN: NaNO3 tinh th + H2SO4 c NaHSO4 + HNO3 + Trong cng nghip: 4NH3 + 5O2 (kk) 4NO + 6H2O; NO + O2 NO2

4NO2 + O2 + 2H2O 4HNO3

b. Mui nitrat: Tt c cc mui nitrat u tan nhiu trong nc v l cht in li mnh. Chng km bn vi nhit v d b phn hu khi nung nng.

Mui nitrat ca kim loi mnh phn hu thnh mui nitrit v oxi:

2KNO3 0t

2KNO2 + O2 Mui nitrat ca a s kim loi nh Mg, Zn, Fe, Cu... phn hu thnh oxit + nit ioxit

v oxi: 2Cu(NO3)2 0t 2CuO + 4NO2 + O2 Lu : 4Fe(NO3)2 0t 2Fe2O3 + 8NO2 + O2 B. Cc dng bi tp v phng php gii

Dng 1: Bi tp v N2 v NH3

-3 0 +1 +2 +4 +5 NH4, NH3 N2 N2O NO NO2


* Cch thit lp cng thc phn t Ax By Cz Dt (x,y,z,t l cc s nguyn dng)

x:y:z:t = A

mA :B

mB :C

mC :D

mD hoc x:y:z:t =

AA%

:BB%

:CC%

:DD%

* Tnh hiu sut:

+ Biu din s mol cc cht ( cho v cn tm) theo phng trnh phn ng + Xc nh tng s mol cc cht ban u v sau phn ng

+ Hiu sut phn ng: H = )()(

lithuyetmolthuctemol

.100%

+ Hiu sut ca c qu trnh: A = %1 aH B = %2 bH C = %3 cH D = %4 dH E

H = H1. H2. H3. H4 = a%.b%.c%.d%.

V d 1: Mt oxit A ca nit c cha 30,43% v khi lng nit. T khi ca A vi khng kh l 1,59. Tm cng thc phn t ca A. Li gii:

t A l NxOy. Theo u bi: %N = 30,43%; %O = 69,57%

x: y = 16

57,69:

1443,30

=1:2 A c cng thc (NO2)n

MA = 46.n = 46 n = 1. Vy cng thc phn t ca A l NO2.

V d 2. Trong mt bnh kn dung tch 56 lit cha N2 v H2 theo t l th tch 1:4, 00C v 200 atm v mt t cht xc tc (th tch cht xc tc khng ng k). Nung nng bnh mt thi gian sau a nhit v 00C thy p sut trong bnh gim 10% so vi so vi p sut ban u. Tnh hiu sut phn ng iu ch NH3.

Li gii

Phng trnh: N2 + 3H2 2NH3

Ban u 100 400 0 (mol) Phn ng x 3x 2x (mol) Cn bng sau p/: 100-x 400-3x 2x (mol) S mol hn hp kh sau phn ng: ns = 100 - x + 400- 3x + 2x (mol) (1)

Tng s mol (N2 v H2) kh ban u : tPV 200.56

n 500mol22, 4RT

.273273

= = =


Trong : = =2H

500.4n 400mol

5 v = =

2N500.1

n 100mol5

p sut trong bnh sau phn ng Ps = 500.4 180atm5

=

cng iu kin nhit p sut p sut t l thun vi s mol kh cha trong bnh:

= = =t t ss s

n p 500.180n 450

n p 200 mol (2)

T (1) v (2) ta c: ns = 100 - x + 400- 3x + 2x = 450 x = 25 mol.

Vy H = = =2pu

2bd

N

N

n25

.100% 25%n 100

V d 3. Hn hp A gm ba kh NH3, N2 v H2. Dn A vo bnh c nhit cao. Sau phn ng phn hu NH3 (coi nh hon ton) thu c hn hp B c th tch tng 25% so vi A. Dn B i qua ng ng CuO nung nng sau loi nc th ch cn li mt cht kh c th tch gim 75% so vi B. Tnh thnh phn % theo th tch ca cc kh trong hn hp A.

Li gii

Gi x, y v z l thnh phn % theo th tch ca ba kh NH3, H2 v N2 trong hn hp A. Ta c: x + y + z = 1 (1) Phng trnh phn ng phn hu NH3: 2 NH3 N2 + 3 H2

x x

2

3x

2

Sau phn ng hn hp B gm (y + 1,5x) hiro v (z + 0,5x) nit. B c th tch tng 25% so vi A tc l VB = 1,25VA = 1,25. do :

( ) ( ) (2)25,1100

125zyx2x5,0zx5,1y ==++=+++

T (1) v (2), rt ra : x = 0,25 Khi B i qua ng ng CuO nung nng th H2 b oxi ho : CuO + H2 Cu + H2O

Loi nc th cht kh cn li l N2. Th tch gim 75% so vi B tc l cn bng 25% ca B, do :


3125,016

5

100

125.

100

25x5,0z ===+

Rt ra: z = 0,3125 - (0,5 . 0,25) = 0,1875 Thay cc gi tr ca x v z vo (1), ta c: 0,25 + y + 0,1875 = 1, rt ra y = 0,5625 Thnh phn % theo th tch ca cc kh trong hn hp A:

%VNH3 = 25% ; %VN2 = 18,75% ; %VH2 = 56,25%

Dng 2: Bi tp s dng nh lut bo ton s mol electron Phng php gii

+ Vit phng trnh cho, nhn electron.

Lu : 2N+5 + 10e N2 ; 2N+5 + 8.e N2O; N+5 + 8.e N-3 (NH4NO3) + Tnh tng s mol electron cho v nhn. p dng LBTT. + S mol HNO3 phn ng =

3NOn

+ 5Nn + (to kh) ;

+ Cho mui M(NO3)x ; nM = 3( )xM NOn ; 3NOn = x. 3( )xM NOn = x. nM ( mol)

V d 1 (H 2002-A). Cho 18,5 gam hn hp X gm Fe, Fe3O4 tc dng vi 200 mL dung dch HNO3 long, un nng v khuy u. Sau khi phn ng xy ra hon ton thu c 2,24 lt kh NO duy nht ktc, dung dch Y v cn li 1,46 gam kim loi.

1. Tnh nng mol/l ca dung dch HNO3 .

2. Tnh khi lng mui trong dung dch Y.

Li gii:

V phn ng xy ra hon ton m cn d kim loi (Fe) HNO3 ht v mui thu c ch c Fe(NO3)2. p dng LBT nguyn t vi N :

23 3 2 3 2HNO Fe(NO ) NO Fe(NO ) Fen 2n n n n 0, 27 mol+= + = =

p dng LBT electron : Gi a, b l s mol Fe v Fe3O4 phn ng. Cc qu trnh nhng, nhn electron :

+2 +8/3 +2 +5 +2Fe Fe 2e ; 3Fe 2e 3Fe ; N 3e N2a 2b 0,3 (1)

a a 2a 3b 2b 3b 0,3 0,1

+ =

LBT e + + +


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