Result Selvi

8/13/2019 Result Selvi

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CHAPTER-IV

RESULTS AND DISCUSSION

Kinetics of oxidation in absence of monomer

The Kinetics of oxiation of lactic acid (LA) by Ce(IV) in the absence of

monomer was carried out at the temperature 30oC and 350C. The rate of oxidant

consumption (-d[Ce(IV)]/dt) were proportional to [Ce(IV)] , (Table1,Fig1)

.Variation of rates with substrate concentration (Table2,Fig 2) suggested the

formation of 1:1 complex intermediates prior to oxidation.The plots of

(-d [Ce (IV) ]/dt)-1against [LA]-1were linear(Table3,Fig3), with an intercept the

complex formation between the oxidant and the substrate in the redox pair. Double

reciprocal plots of (-d[Ce (IV) / dt)-1 vs[H+]-1 were also found to be linear

(Table4 ,fig4).

The results of oxidation can be accounted for by the following scheme

where Ce (IV) represents the first species of oxidation .

scheme I

K1

LA + H+ -----------LA - H+ .......................(i)

------

K2

LA - H+ + Ce(IV) - ------- Complex(c) ..........(ii)Kr

C R .+ Ce(III) + H+ ......................(iii)


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K0

R. + Ce(IV) Products ....................(iv)

Where, C represents the complex formation between the substrate and the

oxidant.

The two eqilibrium K1and K

2were treated separately so that,

K1

= ([LA - H+]eq

) / ([LA]eq

[H+]) ...........(1)

and

[LA]T

= [LA - H+]eq

+ [LA]eq

........................(2)

From equation(1),

[LA - H+]eq

= K1[LA]

eq[H+]

Introducing this value in equation (2),We get,

[LA]T

= K1

[LA]eq

[H+] + [LA]eq

= [LA]eq

(1 + K1[H+]) ........................(3)

Where [LA]eq

denotes the equilibrium concentration of LA also,

[Ce (IV)]T

= [Ce(IV)]

eq

+ [C] .........................(4)

From the kinetic step (2)

K2= [C] / ([LA - H+]

eq[Ce (IV)]

eq)


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[C] = K2[LA-H+]

eq[Ce (IV)]eq ..........................(5)

Substituting equation (5) in equation(4),

[Ce(IV)]T= [Ce(IV)]

eq+K

2[LA - H+]

eq[Ce (IV)]

eq

= [Ce (IV)]eq

(1+K2[LA - H+]

eq) ..........................(6)

Where [Ce(IV)]eq

represents the equitibrium concentration of ceric ion.

By applying steady-state approximation to the intermediate(R

), the

following expression can be derived from the kinetic scheme-I ,steps(iii) and (iv):

-d[R

] / dt = K0[Ce (IV)]

eq[R

] - Kr[C] = 0

therefore

K0[Ce (IV) ]

eq[R

] = Kr[C]

[R

] = [Kr[C] ) / (K0[Ce (IV)]eq.................................(7)

The rate law for the oxidation could then be derived as follows.

From the Kinetic steps,

-d [Ce (IV) / dt = Kr[C]+K0[Ce(IV)]eq[R

]

=Kr[C]+K0[Ce(IV)]eqKr[C] / (K0[Ce(IV)]eq

)

= 2Kr[C]

From the equation (5),


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-d[Ce(IV)] / dt = 2Kr.K

2[LA-H+]

eq[Ce(IV)]

eq

By using the equation (1),

-d[Ce(IV)] / dt = 2KrK

1K

2[LA]

eq[H+][Ce(IV)]

eq

Applying the equation (3) and (6)

-d[Ce(IV)/dt=(2KrK

1K

2[LA]

T[Ce(IV)]

T[H+]/1+ K

1[H+])x(1+K

2[LA-H+]

eq)

=R0

The above equation explain the dependence of the rate on Ce(IV)

concentration and also variable with substrate concentration.The observation of

Michelis-Menton kineties, i.e.,the formation of a complex between the reactants

allow the oxidation data to be treated according to the method of Line Wearer and

Burk.

Thus the above equation can be written as follows:

(2KrK1K2 [LA]T[Ce(IV)]T[H+])

-d[Ce(IV)]/dt =

(1+K1[H+])(1+K 2K 1[LA]eq[H

+])

(2KrK1K2[LA]T[Ce(IV)]T[H+])

=(1+K1K2[LA]T[H

+])/(1+K1[H+])

(2KrK1K2[LA]T[Ce(IV)]T[H+])

=

(1+K1[H+]+ K1K2[LA]T[H

+])


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Taking reciprocal rate in given by,

(-d[Ce(IV)]/dt)-1=1/(2KrK1

K2[LA]

T[Ce(IV)]

T[H+])+1/(2K

rK

2[LA]

T[Ce(IV)]

T)

+ 1/(2Kr[Ce(IV)]

T) ................................(8)

This equation explains the linear plot of(-d[Ce(IV)]/dt)-1 vs[H+]-1,

(-d[Ce(IV)]/dt)-1 vs[LA]-1

Equation (8) explain the dependence of rate on[Ce(IV)].

Thus Kr could be evaluated from the plots of (-d[Ce(IV)]/dt)-1 vs [LA]-1

from the intercepts of the plots of(-d[Ce(IV)]/dt)-1vs[H+])-1, K2could be evaluated

The value of K1can be determined from the slope of the plots of (-d[Ce(IV)]/dt)-1

vs [H+]-1by knowing the values of krand k

2. The calculated data are listed in Table

5. The thermodynamic parameters calculated for the reaction are also listed in the

same table.


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Table 1

[LA] = 0.2 mol.dm-3

= 1.1 mol.dm-3

[H2SO4] = 5 mol. dm-3

Temperature = 300C & 35

0C.

[Ce(IV)] mol. dm-3

10

-7

[-d [Ce(IV)]/dt] mol. dm-3

. sec-1

300C 350C

0.00314 6.9079 5.3289

0.00418 7.6974 7.5

0.00523 8.2895 8.8816

0.00627 8.8816 10.8553

0.00732 10.0658 12.2368

0.00783 10.8553 12.3434

Table 2

[Ce(IV)] = 0.0209 mol.dm-3

= 1.1 mol.dm-3

[H2SO4] = 5 mol. dm-3


0C.

[LA] mol. dm-310- [-d [Ce(IV)]/dt] mol. dm- . Sec-

30 C 35 C

0.02 14.013 14.605

0.03 15.395 15.395

0.04 15.987 16.9740.05 16.579 17.961

0.055 17.566 19.145

0.06 17.961 20.132


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[Ce(IV)] mol. dm-3

Fig.1 Variation of Oxidant

[LA] mol. dm-3

Fig.2 Variation of Reductant

0

2

4

6

8

10

12

14

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

0

5

10

15

20

25

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

10-7[-d[Ce(IV)]/dt]mol.dm-3.S

ec-1

35oC

30oC

10-7

[-d[Ce(IV)]/dt]

mol.dm

-3.

Sec

-1

35oC

30oC


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Table 3

[Ce(IV)] = 0.0209 mol.dm-3

= 1.1 mol.dm-3

[H2SO4] = 5 mol. dm-3


0C.

[LA]-1(mol. dm-3)-1 10 [-d [Ce(IV)]/dt]

-

mol. dm

-

. Sec

-

30

0C 35

0C

50 0.7136 0.6847

33.33 0.6496 0.6496

25 0.6255 0.5891

20 0.6032 0.5568

16.67 0.5693 0.5223

14.29 0.5568 0.4967

Table 4

[Ce(IV)] = 0.0209 mol.dm-3 = 1.1 mol.dm-3

[LA] = 0.2 mol. dm-3


0C.

[H2SO4]-1

(mol. dm-3

)-1

106[-d [Ce(IV)]/dt]-1mol. dm-3. Sec-1

30 C 35 C

20 1.2992 1.1783

3.33 1.1259 1.1014

1.818 1.034 1.0555

1.25 0.9559 0.9744

0.952 0.8587 0.9212

0.769 0.7795 0.8587


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[LA]-1(mol. dm-3)-1


[H2SO4]-1(mol. dm-3)-1

Fig.4 Variation of H2SO4

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 10 20 30 40 50 60

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 5 10 15 20 25

35oC

30oC

35oC

30oC

10

6[

-d[Ce(IV)]/dt]-1mol.

dm

-3.

10

6[

-d[Ce(IV)]/dt]-1

mol.dm

-3.


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Table 5

Rate and thermodynamic parameters for the oxiation of lactic acid in the

absence of monomer

Temperature Kr K

1 K

2 K

a H S

K s-1 dm3.mol-1 dm3.mol-1 KJ.mol-1 KJ.mol-1 J.mol-1k-1

303

308

Oxidation in the presence of monomer

Where the oxidation of lactic acid by Ce(IV) was carried out in dilute

sulphuric acid medium in the presence of monomer it was observed that the rates

of disapperance of ceric ion were directly proportional to [Ce(IV)]. The plots of

rate versus ceric ion concentration were linear (Table6, Fig5). The rate were

variable with substrate conentration (Table7, Fig6). The order with respect to

monomer concentration was found to be unity as sum from the linear plots of rates

versus monomer concentration (Table8, Fig7) which means that, under the present

experimental conditions ceric ions were involved in a M+ Ce(IV)- type initiation

reaction. The plots of (-d[Ce(IV)]/dt)1against [LA]-1were linear with intercept on

the ordinate as shown in the (Table9, Fig8) The plots of(-d[Ce(IV)/dt) -1 vs [H+]

were linear with respect on the rate axis (Table10, Fig 9).

For methyl methacrylate the intercepts of the lines on the y-axis,may arise

due to an one of the following reasons.


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(a)A side reaction involving oxidation of the monomer by ceric ion.

(b) A side reaction involving oxidation of the impurities in the monomer by

ceric ion.The possibility of oxidation of the impurities in the monomer by ceric ion

receives some support from the evidences in the literature , where impurities

present in the polymerization system have been shown to affect the determination

of reaction rates.We therefore conclude that the initiation takes place by a direct

reaction between the monomer and ceric ion.This may probably involves an

electron transfer from the ceric ion to the monmer, producing a radical ion of the

type CH2=CHX,which in similar to the one proposed by bawn and sharp4 in theoxidation of olefins by cobaltic ion. The direct dependence of the rate on monomer

concentration has also been observed in the studies with ceric-reducing agent redox

system..

The above results of oxidation in the presence of monomer can be

accounted for the following scheme.

scheme-II

KCe (IV) + LA complex c ............................(i)

Kr

C R. +Ce(III) + H+ ........................(ii)

R. + Ce(IV) products ........................(iii)

Ki

Ce (IV) +M M

+ Ce(III) .......................(iv)Applying steady state approximation to the intermediate R., the following

expression can be derived for the oxidation in the presence of monomer.

-d[Ce(IV)]/dt=Kr[C]+K

0[Ce(IV)]

eq[R]+K

i[M][Ce(IV)]

eq............(9)


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substituting the value of[R

] from equation (7) in to equation(9),

-d[Ce(IV)]/dt=K

r[C]+K

0[Ce(IV)]

eq

(Kr[C]]/K0[Ce(IV)]

eq

)+Ki[M][Ce(IV)]

eq

=2Kr[C]+K

i[M][Ce(IV)]

eq

Introducing the value of[C] from equation(5)

-d[Ce(IV)]/dt=2KrK

2[LA - H+]

eq[Ce(IV)]

eq+K

i[M][Ce(IV)]

eq...........(10)

substituting the value of[LA-H+]eq

and [Ce(IV)]eq

from equation (1) and

(6) into equation (10),

-d[Ce(IV)]/dt=(2KrK

2[Ce(IV)]

TK

1[LA]

eq[H+]/(1+K

2[LA-H+]

eq)

+Ki[M][Ce(IV)]

T)/(1+K

2[LA - H+]

eq)

=R0+(K

i[M][Ce(IV)]

T)/(1+K

2[LA - H+]

eq)

Where R0 is the rate expression for the oxidation in the absence ofmonomer.

In any case the line weaver-Burk treatment would be still valid for the

oxidation data.

The values of the rate and equlibrium constants can be computed.These are

in Table 13.


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Table 6

[LA] = 0.2 mol.dm-3

= 1.1 mol.dm-3

[H2SO4] = 5 mol. dm-3

Temperature = 300c & 35

0c.

[M] = 0.02 mol.dm

-3

[Ce(IV)] mol. dm-310- [-d [Ce(IV)]/dt] mol. dm- . Sec-

30 C 35 C

0.00314 3.1578 4.9342

0.00418 6.1184 8.6842

0.00523 6.5131 9.0789

0.00627 9.0789 11.6447

0.00732 10.0657 12.6315

0.00784 10.6578 13.0263

Table 7

[Ce(IV)] = 0.0209 mol.dm-3 = 1.1 mol.dm-3

[H2SO4] = 5 mol. dm-3


0C.

[M] = 0.02 mol.dm-3

[LA] mol. dm-3

10

-3[-d [Ce(IV)]/dt] mol. dm

-3. Sec

-1

300C 35

0C

0.02 1.1644 1.6578

0.03 1.3223 1.6973

0.04 1.3618 1.7763

0.05 1.3815 1.8552

0.055 1.4802 1.89470.06 1.5789 1.9539


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[Ce(IV)] mol. dm-3


[LA] mol. dm-3


0

2

4

6

8

10

12

14

16

0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009

0

0.5

1

1.5

2

2.5

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

35oC

30oC

35oC

30oC

10-4

[-d[Ce(IV)]/dt]mol.

dm

-3.

10-3

[-d[Ce(IV)]/dt]mol.

dm

-3.


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Table 8

[Ce(IV)] = 0.0209 mol.dm-3

= 1.1 mol.dm-3

[H2SO4] = 5 mol. dm-3


0C.

[LA] = 0.02 mol.dm

-3

[M] mol. dm-310- [-d [Ce(IV)]/dt] mol. dm- . Sec-

30 C 35 C

0.0004 4.9342 3.9473

0.0005 5.3289 4.3421

0.0006 6.1184 4.7368

0.0007 3.9473 5.1315

0.0008 5.9210 6.1184

0.0009 7.3026 6.9078

Table 9

[Ce(IV)] = 0.0209 mol.dm-3 = 1.1 mol.dm-3

[H2SO4] = 5 mol. dm-3


0C.

[M] = 0.02 mol.dm-3

[LA]-1(mol. dm-3)-1103[-d [Ce(IV)]/dt]-1mol. dm-3. sec-1)-1

300C 350C

50 0.8588 0.6032

30.33 0.7562 0.5892

25 0.7343 0.5629

20 0.7238 0.539018.18 0.6756 0.5278

16.66 0.6333 0.5118


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[M] mol. dm-3

Fig.7 Variation of Monomer

[LA]-1(mol. dm-3)-1


0

1

2

3

4

5

6

7

8

0 0.0002 0.0004 0.0006 0.0008 0.001

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 10 20 30 40 50 60

35oC

30oC

35oC

30oC

10-4

[-d[Ce(IV)]/dt]m

ol.dm

-3.

10

3[

-d[Ce(IV)]/dt]

-1m

ol.dm

-3.


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Table 10

[Ce(IV)] = 0.0209 mol.dm-3

= 1.1 mol.dm-3

[LA] = 0.2 mol. dm-3


0C.

[M] = 0.02 mol.dm

-3

[H2SO4]-1

(mol. dm-3

)-1

10 [-d [Ce(IV)]/dt]

-(mol. dm

-. Sec

-)

-

30 C 35 C

20 0.7562 0.7238

3.333 0.7451 0.7451

1.8181 0.7343 0.7136

1.25 0.7037 0.7037

0.9523 0.6667 0.6496

0.7692 0.6414 0.6255

Table 11

[Ce(IV)] = 0.0209 mol.dm-3

= 1.1 mol.dm-3

[H2SO4] = 5 mol. dm-3


0C.

[M] = 0.02 mol.dm-3

[LA]-1

(mol. dm-3

)-1

10

7[-d [M]/dt]

-1(mol. dm

-3. Sec

-1)-1

300C 35

0C

50 9.2311 0.8541

33.33 4.6153 0.7224

25 3.7509 0.670720 0.8889 0.5522

18.18 0.6956 0.5217

16.66 0.6476 0.4580


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[H2SO4]-1

(mol. dm-3

)-1


[LA]-1

(mol. dm-3

)-1


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 5 10 15 20 25

-2

0

2

4

6

8

10

0 1 2 3 4 5 6 7

35oC

30oC

35oC

30oC

10

3[

-d[Ce(IV)]/dt]-1

(mo

l.dm

-3.

10

7[

-d[M]/dt]-1

(mol.d

m-3

.sec

-


19/27

Table 12

[Ce(IV)] = 0.0209 mol.dm-3

= 1.1 mol.dm-3

[LA] = 0.2 mol. dm-3


0C.

[M] = 0.02 mol.dm

-3

[H2SO4]-1(mol. dm-3)-1

10 [-d [M]/dt]- (mol. dm- . sec- )-

30 C 35 C

20 0.7224 0.9884

3.333 0.4472 0.8163

1.8181 0.3683 0.7224

1.25 0.3354 0.6956

1.9523 0.3183 0.6956

0.7692 0.2981 0.6030

[H2SO4]-1(mol. dm-3)-1


0

0.2

0.4

0.6

0.8

1

1.2

0 5 10 15 20 25

35oC

30oC

10

7[

-d[M]/dt]-1

(mo

l.dm

-3.sec

-


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Rate and thermodynamic parameters for the oxidation of lactic acid in the

presence of monomer

Temperature Kr K1

K2

Ka H S

K S-1 dm3.mol-1 dm3.mol-1 KJ.mol-1 KJ.mol-1 J.mol-1k-1

303

308

Kinetics of polymerization

The polymerization of methyl methacrylate using redox couple Ce

(IV) - lactic acid was carried out at the temperature 300C and 350C under nitrogen

atmosphere. The polymerization was found to takes place without an induction

period, and the steady state rate was attained with in a short time. The rates of

polymerization and also varied with [LA] (Table16, Fig14),but tend to become

independent of substrate at high subtrate concentration. The rate of polymerization

were proportional to [M] being linear passing through the origin (Table14, Fig12)

furnishing strong, evidence, for the mutual termination of the growing chain. The

rates were decreased by [H+]showing 0.5 order in [H+](Table15, Fig13).

The initial rate was increased with increase in monomer concentration at

fixed [Ce(IV)], [LA]and [H2SO

4]. It was found that the greater the monomer the

greater the possibility of initiation by primary radicals.

All the above data of polymerization can be accounted for by the following

scheme.

scheme-III


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K

Ce (IV) + LA ----- complex C ................(i)

KrC -------- R

+ Ce(III) + H+ ..............(ii)

Ko

R.+ Ce(IV) ------- products ..............(iii)

Ki

R

+ M -------- R - M

............(iv)

Kp

R - M

+ M ------- R - M2

etc

Kt

2R Mn

-------- polymer

The mutual termination assumed here does not distinguished betweenthe combination and disproportionation modes.

The steady state concentration of radical intermediates will be given by the

following equation

d[R

]/dt=Kr[C]-K

o[R

][Ce(IV)]eq

-Ki[R

][M]=0

[R

]=K1[C] / K0[Ce (IV)]eq+Ki[M]) .............................(ii)

substituting the value of [C] from the equation (5),

[R.]=(K

rK

2[LA- H+]

eq[Ce(IV)]

eq) / K

0[Ce(IV)]

eq+K

i[M]) .........(12)


22/27

then,

d[R Mn

] / dt = Ki[R

][M] - Kt[R Mn

]2=0

Ki[R

.][M] = K

t[R-M

.n]2

[R- Mn.] = (K

i/K

t)[R

.][M]1/2 ..........................(13)

By appling the value of [R.]from equation (12)

(KrK

2[LA - H+]

eq[Ce[(IV)

]eq) 1/2

[R- Mn

] = ((Ki/K

t)[M]1/2 .(14)

K0[Ce(IV)

eq+K

i[M]

The rate of polymerization can be writen as

-d[M] / dt =Kp[M][R-Mn

] .............................(15)

Combining equation(14) and (15) the following expression can be derived

(KiK

rK

2[LA - H+]

eq[Ce(IV)]

eq1/2

--d[M]/dt = Kp/Kt1/2[M]3/2 .......(16)(K

0[Ce(IV)]

eq+ K

i[M]

Introducing the equation (3) and (6) in to (16)


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Kp/Kt1/2[M]3/2 (K

iK

rK

2(Ce(IV)

T/ 1+K

2[LA - H+]

eqK

i[H] + [LA]

-d[M]/dt =

1+K1

[H+] / K0Ce(IV)]

T/ (1+K2[LA -H

+]eq

) + Ki[M

.])1/2

Rearranging the above equation

-d[M]/dt = [M]3/2[Ce(IV)]t1/2[LA]1/2

T[H+]1/2.Kp/K

t1/2][K

iK

rK

1K

2/K

0]1/2 x

(a constant) ....................................(17)

The data of polymerization statisfy the requirments of the above equation.

By applying the value of [Ce(IV)]eq in the equation (16) the equation

becomes,

-d[M]/dt = (Kp

/Kt1/2) [M] 3/2[Ce(IV)]

T1/2/ (1+K

2[LA-H+]

eq)

[LA - H+]eq

1/2 + Kt1/21+K

2[LA-H+]

eqK

iK

rK

2(K

0[Ce(IV)]

eq+K

i[M]))1/2............(18)

Under conditions such that

K0[Ce(IV)]

eq


24/27

presence of monomer. The value of Kp and Ktwhich refer to the reactivity of the

growing radicals (R - M.) towards the monomer and towards themselves

respectively depend not on nature of the monomer but on the medium and

temperature.

Effect of organic substrate

On increasing the concentration of lactic acid the rate of polymerization

was increased the plots of versus [LA] were linear and passed through the origin.

Effect of [H]+

The increase in concentration of acid leads to a decrease in the rate Rp (obs) at

constant ionic strength. But Rp (obs) was independent of [H+]. This may be

attributed to formation of less active Ce(IV) species given by the following

eqilibrium.

Ce(IV) + H2SO

4 ---> CeSO

4 (III) + H+

At constant [H2SO

4], the increase in [H+] will lead to a decrease in the ratio

Ce[SO4] (III) / Ce(IV). Hence with lower [H+] the reactivity of CeSO

4(III)

predominates where as at higher [H+] the effect was reveserd.

Effect of Ce(IV)

It was observed that Rp (obs) increase with increasing Ce(IV) concentration. This

can be explained by an increase number of Ce(IV) in the stern layer of SDS

micelles due to electrostatic attraction.The plot of Rp (obs) Vs Ce(IV) shows a

straight line passing through the origin.


25/27

Table 14

[Ce(IV)] = 0.0209 mol.dm-3

= 1.1 mol.dm-3

[LA] = 0.2 mol. dm

-3

Temperature = 30

0

C & 35

0

C.[H2SO4] = 5 mol.dm

-3

[M] mol. dm-3Rpx 10

-7

30 C 35 C

0.0004 1.8655 1.5112

0.0005 2.3488 2.0239

0.0006 2.8537 2.6232

0.0007 3.3288 3.1013

0.0008 3.8259 3.6859

0.0009 4.4411 4.2285

Table 15

[LA] = 0.2 mol.dm-3

= 1.1 mol.dm-3

[H2SO4] = 5 mol. dm-3 Temperature = 300C & 350C.

[M] = 0.02 mol.dm-3

[Ce(IV)] mol. dm-3

Rpx 10

-7

300C 350C

0.00314 2.9076 2.6588

0.00418 2.9243 2.8360

0.00523 2.9423 2.9068

0.00627 3.0297 2.9423

0.00732 3.0658 2.9778

0.00784 3.1017 3.0133


26/27

[M] mol. dm-3

Fig.12 Variation of Monomer

[Ce(IV)] mol. dm-3


0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 0.0002 0.0004 0.0006 0.0008 0.001

2.6

2.65

2.7

2.75

2.8

2.85

2.9

2.95

3

3.05

3.1

3.15

0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009

35oC

30oC

35oC

30oC

Rp

x10-7

Rp

x10-7


27/27

Table 14

[Ce(IV)] = 0.0209 mol.dm-3 = 1.1 mol.dm-3

[H2SO4] = 5 mol. dm

-3

Temperature = 30

0

C & 35

0

C.[M] = 0.02 mol.dm

-3

[LA] mol. dm-3

Rpx 10

-

30 C 35 C

0.02 0.3607 3.8981

0.03 0.7214 4.6083

0.04 0.8878 4.9634

0.05 3.7455 6.0288

0.055 4.7859 6.3806

0.06 5.1327 7.2663

[LA] mol. dm-3


-1

0

1

2

3

4

5

6

7

8

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

35

o

C

30oC

Rp

x10-8

Result Selvi

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