AP Chemistry - Oak Park Independent  · Web viewNaCl BaCl2• 2 H2O CaCO3 CuSO4• 5 H2O Al(NO3)3• 9 H2O BaSO4 Ni(NO3)2• 6 H2O Use the results of the following observations or

AP Chemistry

AP Chemistry 11: EquilibriumSalts and Complex IonsName _________________________

A.Ionic Compounds (2.7 to 2.8, 4.2)

1.name and formula

a.cations

1.named the same as metal (Na+ = sodium)

2.polyatomic cations with ium ending

NH4+ (ammonium), H3O+ (hydronium)

3.charge based on periodic table position

4.assume all transition metals are 2+

a.use Roman numeral for multiple cations per atom: (Fe2+ -iron(II), Fe3+ -iron(III))

b.important exceptions: Cr3+, Ag+

b.anions

1.ide ending

a.monatomic: Cl- (chloride)

b.binary: OH- (hydroxide), CN- (cyanide)

2.oxyanion (ate and ite ending)

C2H3O2-

acetate

MnO4-

permanganate

CO32-

carbonate

NO3-

nitrate

CrO42-

chromate

PO43-

phosphate

Cr2O72-

dichromate

SO42-

sulfate

a.use "bi" prefix when H is added to anion:

HCO3- (bicarbonate). HSO4- (bisulfate)

b.use "ite" suffix when one O is removed:

SO32- (sulfite), NO2- (nitrite)

c.when non-oxygen atom is a halogen:

ClO4-

ClO3-

ClO2-

ClO-

perchlorate

chlorate

chlorite

hypochorite

c.empirical formula (criss-cross method)

1.charges become opposite's subscript

2.Al3+ and SO42- Al2(SO4)3

2.predicting solubility

a.solubility guidelines for predicting MX(s) (memorize)

Cations

(M)

Anions (X)

NO3-

Cl-, Br-, I-

SO42-

OH-, S2-

Others

Alkali Metal

S

S

S

S

S

NH4+

S

S

S

S

S

Sr2+,Ba2+

S

S

I

S

I

Ag+

S

I

S

I

I

Hg22+, Pb2+

S

I

I

I

I

Others

S

S

S

I

I

b.precipitation reaction (ion exchange)

1.MX(aq) + M'X'(aq) MX'(s) + M'X(aq)

2.net ionic: M+ + X'- MX'(s)

B.Solubility Equilibrium (17.4-17.5)

1.ionic compound (salt) equilibrium with its ions

a.MmXn(s) m Mn+(aq) + n Xm-(aq)

b.Ksp = [Mn+]m[Xm-]n (Ksp or mass action expression)

1.subscripts become exponents

2.MmXn(s) is not included [ ] doesn't change

2.solubility equilibrium problems

a.determine one [ ]E, given the other [ ]E and Ksp

Write a Ksp expression from formula

fill in Ksp and [ ] (Don't multiple [ ] by subscript)

solve for missing concentration

b.determine solubility (mol/L) s, given Ksp

set up "ICE Box" (shaded boxes are given)

[ ]

MmXn m Mn+ + n Xm-

I

0

0

C

+ms

+ns

E

ms

ns

solve for s, Ksp = (ms)m(ns)n

general solutions

MX, then Ksp = (s)(s) = s2

MX2 or M2X, then Ksp = (s)(2s)2 = 4s3

MX3 or M3X, then Ksp = (s)(3s)3 = 27s4

c.determine solubility s, given Ksp and [Xm-]o or [Mn+]o

set up "ICE Box" (shaded boxes are given)

[ ]

MmXn m Mn+ + n Xm-

I

0

[Xm-]o

C

+ms

+ns

E

ms

[Xm-]o

solve for s, (Ksp = (ms)m[Xm-]on)

d.determine Ksp, given solubility (s)

set up "ICE Box" (shaded boxes are given)

[ ]

MmXn m Mn+ + n Xm-

I

0

0

C

+ms

+ns

E

ms

ns

solve for Ksp = (ms)m(ns)n

e.determine if a precipitate will form, given [ ]o

write Ksp expression, set equal to Q

substitute [ ]o of each ion into the expression

if Q > Ksp, then a precipitate forms

if Q < Ksp, then no precipitate forms

C.Factors that Affect Solubility (17.5)

1.common ion effect

a.salts are less soluble in solution with common ion

b.Le Chatelier's principle: MX(s) M+ + X-

(higher [ ] of a product ion shifts equilibrium left)

2.addition of acid (H+)

a.salt are more soluble in solution with H+

b.Le Chatelier's principle: MX(s) + H+ M+ + HX(aq)

(higher [ ] of reactant shifts equilibrium right)

CaCO3(s) + 2 H+ Ca2+ + H2CO3(aq) CO2(g) + H2O

Mg(OH)2(s) + 2 H+ Mg2+ + 2 H2O

CuS(s) + 2 H+ Cu2+ + H2S(g)

c.salts with Cl-, Br-, I-, SO42- are unaffected by H+

3.formation of complex ions

a.polar molecules or anions are strongly attracted to transition metal cation forming a complex ion

1.polar molecule or anion is called ligand

a.molecules: H2O, NH3

b.anions: Cl-, CN-, SCN-, OH-

2.number of ligands (coordination number) is usually 2, 4 or 6 (often 2 x cation charge)

3.[Cu(NH3)4]SO4tetraaminecopper(II) sulfate

a.complex ion is placed in brackets

b.counter ion is outside brackets

c.compound is electrically neutral

b.formation constant, Kf

Cu2+ + 4 CN- Cu(CN)42-

Kf = [Cu(CN)42-]/[Cu2+][CN-]4

(note: compared to Ksp, Kf is backward and complex is included)

4.determine equilibrium position

example: Will AgCl dissolve in concentrated NH3?

AgCl(s) Ag+ + Cl- Ksp = 1.8 x 10-10

Ag+ + 2 NH3(aq) Ag(NH3)2+Kf = 1.7 x 107

AgCl(s) + 2 NH3(aq) Ag(NH3)2+ + Cl-K = 3.1 x 10-3

answer: K < 1 AgCl is only soluble if [NH3] is high enough to shift equilibrium toward products.

5.amphoterism: some metal oxides and hydroxides are soluble in both strong acid and strong base

example Al(OH)3(s)

1.acid: Al(OH)3 Al3+ + 3 OH-Ksp = 2 x 10-31

3 H+ + 3 OH- 3 H2OKw-3 = 1 x 1042

Al(OH)3 + 3 H+ Al3+ + 3 H2OK = 2 x 1011

answer: K > 1 soluble in strong acid (H+)

2.base: Al(OH)3 Al3+ + 3 OH-Ksp = 2 x 10-31

Al3+ + 4 OH- Al(OH)4-Kf = 1 x 1033

Al(OH)3 + OH- Al(OH)4-K = 2 x 102

answer: K > 1 soluble in strong base (OH-)

Experiments

1.Solubility LabMix cations and anions together to determine solubility and compare results to solubility table.

a.Fill in the formula of any expected precipitate.

NO3-

I-

SO42-

S2-

OH-

PO43-

Na+

NH4+

Ba2+

Ag+

Pb2+

Al3+

Add 1 drop of each cation (nitrate salt) along a row.Add 1 drop of each anion (sodium salt) along a column. Write the color for any precipitate that forms.

b.Fill in the color of any precipitate that forms.

NO3-

I-

SO42-

S2-

OH-

PO43-

Na+

NH4+

Ba2+

Ag+

Pb2+

Al3+

c.Are there any precipitates that you expected to form that didn't or that didn't form when you expected them to?

2.Solubility Product Constant LabDetermine the [CrO42-] of saturated AgCrO4 solution by spectrophotometry, calculate Ksp for AgCrO4 and compare it to the expected value.

Fill three cuvette tubes with the K2CrO4 standards. Set the spectrophotometer to 375 nm and measure absorbance.

a.Calculate the CrO42- concentration for each standard and record its absorbance.

Volume (mL)

[CrO42-]

(mol/L)

Absorbance

1.0 x 10-3 M K2CrO4

Total

0

20

0

0

1.0

20.

2.0

20.

3.0

20.

b.Graph the absorbance vs. [CrO42-].

Absorbance

0.50

0.40

0.30

0.20

0.10

0

0.50

1.0

1.5

Concentration ( x 10-4 mol/L)

c.Determine the slope of the line, which equals a in Beer's law. A (Absorbance) = a (absorptivity) b (cuvette width1 cm) c (concentration).

To a clean test tube, add 5 mL distilled water, 5 drops of 0.1 M AgNO3 and 15 drops of 0.1 M K2CrO4. Stopper the tube and shake periodically for 10 minutes. Centrifuge for 3 minutes (be sure a test tube with similar amount of liquid is in the slot opposite your tube). Pour off the liquid, called the supernatant, while leaving the precipitate in the test tube (decant). Add 5 mL of 0.1 M NaNO3 to the test tube. Repeat the stopper, shake, centrifuge, decant and wash cycle. Centrifuge. Pipet the clear, pale yellow supernatant to a cuvette (be careful not to include any precipitate). Measure the absorbance of the solution.

d.Record the absorbance, use Beer's law to calculate [CrO42-], which is the solubility, and then calculate Ksp.

Absorbance

[CrO42-]

Ksp

e.The actual Ksp for Ag2CrO4 is 1.1 x 10-12. Use this value and work backward through the calculations to determine what the absorbance should have been.

f.Will the following produce an experimental result that is greater than expected or less? Explain you answer.

(1)Dirt or fingerprints on the cuvette.

(2)The original chromate was not completely washed from the Ag2CrO4 precipitate.

(3)Some precipitated Ag2CrO4 was included with the supernatant.

(4)The concentration of K2CrO4 used for the chromate standards was greater than 1.0 x 10-3 M.

(5)The concentration of K2CrO4 used for the chromate standards was less than 1.0 x 10-3 M.

3.Qualitative Analysis LabPerform a series of procedures to isolate and test for the presence of one or more of the "group 1" cations (Ag+, Pb2+ and Hg22+) in an unknown.

Step 1: Add 2 drops of 6 M HCl to 20 drops of the known solution in a small test tube. Place in a boiling water bath (250 mL beaker half filled with tap water) for 2 minutes and stir occasionally with a glass rod. Centrifuge the hot solution and quickly decant. Save the supernatant for step 2 and the precipitate for step 3.

Step 2: Add 1 drop of 6 M HC2H3O2 and 2 drops of 0.1 M K2CrO4 to the supernatant from step 1. A yellow precipitate confirms the presence of Pb2+.

Step 3: Add 10 drops of 6 M NH3 to the precipitate from step 1 and stir thoroughly. Centrifuge and decant. Save the supernatant for step 4. A gray or black precipitate confirms the presence of Hg22+.

Step 4: Add 6 M HNO3 to the supernatant from step 3 until it is acidic toward litmus paper (dip the stirring rod into the supernatant then place it on blue litmus paperturns red in acid). A white precipitate confirms the presence of Ag+.

Repeat steps 1-4 with the unknown and record your results.

a.What do Ag+, Pb2+ and Hg2+ have in common?

b.How is Pb2+ separated from AgCl(s) and Hg2Cl2(s)?

c.How is the presence of Pb2+ confirmed?

d.Ag+ separated from Hg2Cl2(s)?

e.How is the presence of Hg22+ confirmed?

f.How is the presence of Ag+ confirmed?

g.Which ions are present in your unknown?

Pb2+

Ag+

Hg22+

Practice Problems

A.Ionic Compounds

1.Fill in the charge of each cation and anion, and then complete the formula and name of the ionic compound.

Cation

Anion

Formula

Name

Fe(II)2+

O2-

Ca2+

H-

Al3+

Br-

Ag+

S2-

Zn2+

I-

Pb(IV)4+

PO43-

Cu(II)2+

SO42-

Cr3+

NO3-

Co(III)3+

Cl-

Sn(IV)4+

MnO4-

Hg2(I)2+

CO32-

Na+

Cr2O72-

Mg2+

C2H3O2-

Ni2+

CrO42-

K+

CO32-

2.Write formulas for the cation, anion and compound named.

Name

Cation

Anion

Formula

Ammonium carbonate

Aluminum acetate

Silver sulfate

Lead(IV) chlorite

Copper(II) nitrite

Sodium cyanide

Copper(I) fluoride

Manganese(IV) oxide

Iron(III) sulfite

Magnesium dichromate

Mercury(II) hydroxide

Potassium phosphate

Sodium bicarbonate

Tin(II) oxalate

3.Write the formula for the oxyanions of iodine.

IO4-

IO3-

IO2-

IO-

4.For each pair of salts, cross out the spectator ions and then write a net ionic equation for the precipitation reaction.

sodium carbonate +

barium nitrate

mercury(I) sulfate + ammonium chloride

magnesium nitrate + sodium hydroxide

lead(II) nitrate + potassium bromide

B.Solubility Equilibrium

5.A saturated solution of Ba3(PO4)2 (Ksp = 6 x 10-39) has a [Ba2+] = 5 x 10-4 M. Calculate [PO43-].

6.A saturated solution of PbSO4 (Ksp = 1.8 x 10-8) has a [SO42-] = 2 x 10-4 M. Calculate [Pb2+].

7.A solution contains [Ba2+] = 0.0040 M and [Pb2+] = 0.0060 M. What concentration of F- will just precipitate one of the ions? Which one will precipitate first?

(BaF2 Ksp = 1.8 x 10-7, PbF2 Ksp = 7.1 x 10-7)

8.Consider Ag3PO4 (Ksp = 1.0 x 10-16).

a.What is the solubility in pure water?

[ ]

I

C

E

b.What is the solubility in 0.0010 M Na3PO4?

[ ]

I

C

E

9.Consider Ag2CrO4 (Ksp = 1 x 10-12).

a.What is the solubility in pure water?

[ ]

I

C

E

b.How many grams are dissolved in water to make one liter of solution?

c. How many grams dissolve in 0.100 M K2CrO4 to make 100 mL of solution?

[ ]

I

C

E

10.The solubility of AgCl is 1.3 x 10-5 M. What is Ksp?

11.The solubility of LaF3 is 9.3 x 10-6 M. What is Ksp?

12.500. mL of a saturated solution contains 0.0651 g of MgF2 at 25oC.

a.What is the solubility in mol/L?

b.What is Ksp?

13.The solubility of BaC2O4 is 22 mg/L.

a.What is the solubility in mol/L?

b.What is Ksp?

14.Will the precipitate, Al(OH)3 (Ksp = 2 x 10-31), form when 200. mL of 1 x 10-6 M of Al(NO3)3 is mixed with 300. mL of 5 x 10-6 M of Ba(OH)2? Determine

[Al3+]

[OH-]

Q

ppt?

15.Will the precipitate, Ca3(PO4)2 (Ksp = 1 x 10-33), form when 250 mL of 0.40 M of ammonium phosphate is mixed with 450 mL of 0.125 M of calcium chloride?

[Ca2+]

[PO43-]

Q

ppt?

16.The initial concentrations are [Mg2+] = [Sr2+] = 0.02 M and [CO32-] = 2 x 10-7 M. Will a precipitate form, and if so what is it? (MgCO3 Ksp = 7 x 10-6, SrCO3 Ksp = 6 x 10-10)

SrCO3

MgCO3

C.Factors that Affect Solubility

17.What does the difference between the two answers from questions (8.a) and (8.b) illustrate?

18.Explain the observations using chemical equations.

a.Statues made of marble (CaCO3) that are displayed in polluted (acidic air) cities lose their definition over time.

b.Milk of Magnesia is a medication that absorbs excess stomach acid contains Mg(OH)2.

19.Correct the formulas of the complex compounds.

Name

Formula

Corrected

hexammineiron(II) sulfate

[Fe(NH3)4](SO4)2

potassium tetracyanonickelate(II)

[Ni(CN)4]K4

20.Complete the complex ion synthesis reactions and write a Kf expression.

Ag+ + 2 NH3

Cu2+ + 4 Cl-

Al3+ + 4 OH-

Fe3+ + SCN-

21.Explain the observations using chemical equations.

a.AgCl is soluble in concentrated ammonia solution.

b.Ammonia added to a solution of Cu(NO3)2 turns the solution from light blue to dark blue.

22. Given the following equilibriums with their constants.

BaF2(s) Ba2+ + 2 F-Ksp = 1.8 x 10-7

Cr3+ + 4 OH- Cr(OH)4-Kf = 8.0 x 1029

Cr(OH)3(s) Cr3+ + 3 OH-Ksp = 1.6 x 10-30

Cu2+ + 4 NH3(aq) Cu(NH3)42+Kf = 5.0 x 1012

Cu(OH)2(s) Cu2+ + 2 OH-Ksp = 4.8 x 10-20

HF(aq) H+ + F-Ka = 6.8 x 10-4

H2O(l) H+ + OH-Kw = 1.0 x 10-14

H2S(aq) 2 H+ + S2-K = 1.0 x 10-20

MnS(s) Mn2+ + S2-Ksp = 2.5 x 10-13

Calculate K for the equilibriums below.

a.MnS(s) + 2 H+ Mn2+ + H2S(aq)

b.Cu(OH)2(s) + 4 NH3(aq) Cu(NH3)42+ + 2 OH-.

c.BaF2(s) + 2 H+ Ba2+ + 2 HF(l)

d.Cr(OH)3(s) + 3 H+ Cr3+ + 3 H2O(l)

e.Cr(OH)3(s) + OH- Cr(OH)4-

f.What property of Cr(OH)3 is illustrated by the answers from parts (d) and (e)?

Practice Multiple Choice

Briefly explain why the answer is correct in the space provided.

1.What is the correct formula for hypochlorite?

(A)ClO-(B)ClO2-(C)ClO3-(D)ClO4-

2.What is the correct formula for copper(II) sulfate?

(A)CuS(B)Cu2S(C)CuSO3(D)CuSO4

3. Which of the following is the correct name for the compound with formula Ca3P2?

(A)Calcium phosphite(B)Tricalcium diphosphorus

(C)Calcium phosphate (D)Calcium phosphide

4.Which is the net ionic equation for the precipitation reaction between Lead(II) nitrate and sodium phosphate?

(A)Na+ + NO3- NaNO3(s)

(B)3 Pb(NO3)2(aq) + 2 Na3PO4(aq)

6 NaNO3(s) + Pb3(PO4)2(aq)

(C)3 Pb2+ + 2 PO43- Pb3(PO4)2(s)

(D)3 Pb(NO3)2(aq) + 2 Na3PO4(aq)

Pb3(PO4)2(s) + 6 NaNO3(aq)

5.0.20-L of 0.20 M K2CO3 is added to 0.30-L of 0.40 M Ba(NO3)2. Barium carbonate precipitates. The concentration of barium ion, Ba2+, remaining in solution is

(A) 0.15 M(B) 0.16 M(C) 0.20 M(D) 0.24 M

6.

Na3PO4(aq) + 3 AgNO3(aq) Ag3PO4(s) + 3 NaNO3(aq)

100 mL of 1.0 M Na3PO4 is mixed with 100 mL of 1.0 M AgNO3. Which is the order of increasing concentration of the ions remaining in solution?

(A)[PO43-] < [NO3-] < [Na+]

(B)[PO43-] < [Na+] < [NO3-]

(C)[NO3-] < [PO43-] < [Na+]

(D)[Na+] < [NO3-] < [PO43-]

7.An aqueous solution contains Pb2+, Fe2+, and Cu2+ ions. Which will separate Pb2+ from the other ions at 25oC?

(A)Adding dilute Na2S solution

(B)Adding dilute HCI solution

(C)Adding dilute NaOH solution

(D)Adding dilute NH3 solution

8. Which is LEAST soluble in water?

(A)(NH4)2SO4 (B)KMnO4

(C)BaCO3 (D)Zn(NO3)2

9. Which compound is NOT appreciably soluble in water but is soluble in dilute hydrochloric acid?

(A)Mg(OH)2

(B)K2CO3

(C)CuSO4

(D)(NH4)2SO4

Questions 10-12 refer to the following solid compounds.

(A)PbSO4 (B)CuSO4 (C)KMnO4 (D)KCl

10. Is purple in aqueous solution

11. Is blue and very soluble in water

12. Is white and insoluble in water

13. Which occurs when NH3 is mixed with 0.1 M Cu(NO3)2?

(A)A dark red precipitate forms and settles out.

(B)Separate layers of immiscible liquids form.

(C)The color turns from light blue to dark blue.

(D)Bubbles of ammonia gas form.

14.The formula for hexaamineiron(II) sulfate is

(A)[Fe(NH3)6]SO4(B)SO4[Fe(CN)6]

(C)[Fe(NH3)4]SO4(D)[Fe(NH3)6]2(SO4)3

15. Cl-, OH- and SO42- are added to three samples of a colorless, 0.10 M solution, respectively. Which cation could be present in the solution if no change is observed in any sample?

(A)Ni2+ (B)Ag+(C)Ba2+ (D)Na+

Questions 16-20 Answer the following questions that relate to the solubility of Al(OH)3 (Ksp is 2 x 10-31 at 25oC).

16.The [Al3+] at 25oC when [OH-] = 1 x 10-4 M is

(A)(2 x 10-31)/(1 x 10-12) (B)(2 x 10-31)/3(1 x 10-4)

(C)[(2 x 10-31)/(1 x 10-4)]3(D)(1 x 10-12)/(2 x 10-31)

17.The solubility at 25oC is

(A)27(2 x 10-31)4(B)4(2 x 10-31)3

(C)27(2 x 10-31)(D)[(2 x 10-31)/27]

18.Ksp at 50oC when the solubility is 1.0 x 10-6 M is

(A)5.3 x 10-19(B)2.7 x 10-19

(C)2.7 x 10-23(D)2.0 x 10-14

19.Which is true of a mixture where the initial concentrations of [OH-] and [Al3+] are 1 x 10-8 M at 25oC?

(A)Q = 1 x 10-8 Al(OH)3 will precipitate

(B)Q = 27 x 10-8 Al(OH)3 will precipitate

(C)Q = 1 x 10-32 Al(OH)3 will NOT precipitate

(D)Q = 27 x 10-32 Al(OH)3 will NOT precipitate

20.What is the equilibrium constant for the following reaction: Al(OH)3 + OH- Al(OH)4-? (Kf = 1.0 x 1033 for Al(OH)4-)

(A)2.0 x 10-2(B)2.0 x 102

(C)2.0 x 104(D)8.0 x 106

21.

MnS(s) + 2 H+ Mn2+ + H2S(g)

Ksp, for MnS in 5 x 10-15 and K for the dissociation of H2S is 1 x 10-20. What is the equilibrium constant for the reaction?

(A)5 x 10-15(B)5 x 10-8

(C) 2 x 10-6(D) 5 x 105

22.The solubility of CuI is 2 x 10-6 M. What is the solubility product constant, Ksp, for CuI?

(A) 1.4 x 10-3

(B) 2 x 10-6

(C) 4 x 10-12

(D) 2 x 10-12

23. What is the solubility of Ag2CrO4 (Ksp = 8 x 10-12)?

(A)8 x 10-12 M (B)2 x 10-12 M

(C)(4 x 10-12) M(D)(2 x 10-12) M

24.How many moles of NaF must be dissolved in 1 L of a saturated solution of PbF2 at 25oC to reduce the [Pb2+] to

1 x 10-6 M? (Ksp PbF2 at 25oC = 4 x 10-8)

(A) 0.02(B) 0.04(C) 0.1(D) 0.2

25. A solution containing cations was treated with 0.1 M HCl. The white precipitate formed was filtered and washed with hot water. A few drops of 0.1 M K2CrO4 were added to the hot water filtrate and a bright yellow precipitate was produced. The white precipitate remaining on the filter paper was readily soluble in ammonia solution. What two ions could have been present in the unknown?

(A)Ag+ and Hg22+ (B)Ag+ and Pb2+

(C)Ba2+ and Ag+ (D)Ba2+ and Hg22+

Practice Free Response

1.For each reaction, in part (1) write a net ionic balanced equation and in part (2) answer the question about the reaction. Assume that solutions are aqueous unless otherwise indicated.

a.A solution of sodium hydroxide is added to a solution of lead(II) nitrate.

(1)Balanced equation:

(2)If 1.0 L volumes of 1.0 M solutions of sodium hydroxide and lead(II) nitrate are mixed together, how many moles of product(s) will be produced?

b.Excess nitric acid is added to solid calcium carbonate.

(1)Balanced equation:

(2)Briefly explain why statues made of marble (calcium carbonate) displayed outdoors in urban areas are deteriorating.

2.The identity of an unknown solid is to be determined. The compound is one of the seven salts in the following table.

NaCl

BaCl2 2 H2O

CaCO3

CuSO4 5 H2O

Al(NO3)3 9 H2O

BaSO4

Ni(NO3)2 6 H2O

Use the results of the following observations or laboratory tests to explain how each compound may be eliminated or confirmed. The tests are done in sequence from (a) through (e). Explain your reasoning.

a.The unknown solid is white. Which two compounds can be eliminated because they have color?

b.The unknown is soluble in water. Which other two compounds can be eliminated because they are insoluble in water.

c.The unknown forms a white precipitate when AgNO3(aq) is added. Which other compound can be eliminated because it is soluble in AgNO3(aq)?

d.The unknown loses mass when carefully heated. Which other compound can be eliminated because it does not lose mass when carefully heated.

e.Describe a test that can be used to confirm the identity of the remaining unknown compound. Limit your confirmation test to a reaction between an aqueous solution of the unknown compound and an aqueous solution of one of the other soluble salts listed in the table. Describe the expected results of the test; include the formula of the product.

3.Answer the questions that relate to Ca(OH)2 Ksp is 1.8 x 10-11.

a.A saturated solution has a [OH-] = 2.0 x 10-4 M. Calculate [Ca2+].

b.Calculate the solubility.

c,Calculate the mass of Ca(OH)2 that can be dissolved in water to make 1.50 L of solution?

d.Calculate the solubility of Ca(OH)2 in 1.0 x 10-3 M NaOH.

e.How many grams of Ca(OH)2 can you dissolve in 100 mL of 1.0 x 10-3 M NaOH?

f.At a different temperature, the solubility of Ca(OH)2 is 0.15 g/L. What is the Ksp?

g.Will Ca(OH)2 precipitate when 250 mL of 0.0040 M of sodium hydroxide is mixed with 450 mL of 0.0125 M of calcium chloride? Justify your answer.

h.A solution contains [Ca2+] = 4.0 x 10-3 M and [Mg2+] = 1.0 x 10-4 M. What concentration of OH- will just precipitate one of the ions? Which one will precipitate first? Justify your answer. (Mg(OH)2 Ksp = 6.0 x 10-12)

i.Calculate K for: Ca(OH)2(s) + 2 H+ Ca2+ + 2 H2O.

(H2O H+ + OH- Kw = 1.0 x 10-14)

j.Is Ca(OH)2 soluble in HF? Justify your answer.

(HF(aq) H+ + F- Ka = 6.8 x 10-4)