Jee 2014 Booklet5 Hwt Chemical Kinetics

Vidyamandir Classes DATE :

TIME : 30 Minutes

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TEST CODE : CHK [1]

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 This test contains a total of 10 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking. Choose the correct alternative. Only one choice is correct. 1.

2.

3.

For the reaction : 2N 2O5   4NO 2  O 2 , the rate of reaction in terms of O 2 is d O 2  / dt. In terms of

(A)

d[Br2 ] d[Br  ] (B)  dt dt

d[Br2 ] 3 d[Br  ]  dt 5 dt

N 2O5 , it will be:

(C)

d[Br2 ] 3 d[Br  ] (D)  dt 5 dt

d[Br2 ] 5 d[Br  ]  dt 3 dt

(A)

d[N 2O5 / dt

(C)

1 d N 2O5   2 dt

(D)

d N 2O5 / dt 2

7.

d N 2O5  dt

In the reaction A  B   Products, keeping [A] constant if [B] is doubled ; the rate becomes double and keeping [B] constant if [A] is doubled ; the rate becomes four times. The order of reaction is : (A) 1 (B) 2 (C) 3 (D) 4

8.

very slow fast (D)

9.

(B) slow Moderate in speed

6.

In a reaction A   B ; the rate of reaction increase

mole L1s 1

(B)

mole 1Ls 1

(C)

s 1

(D)

mole 2 L2s 1

 2NOCl  g  , when For a reaction 2NO  g   Cl2  g  

For the reaction : N 2  3H 2   2NH3 ;

NH3   2  104 mol L1s 1 , t

H  the value of   2  would be : t

The conversion of A   B follows second order kinetics. Doubling the concentration of A will increase the rate of formation of B by a factor of : (A) 1/4 (B) 2 (C) 1/2 (D) 4

10.

(A)

1  104 mol L1s 1

(B)

3  104 mol L1s 1

(C)

4  104 mol L1s 1

(D)

6  104 mol L1s 1

The

rate

constant

for

the

2N 2O5   4NO 2  O 2 is 3.0  10

In the following reaction, how is the rate of appearance of the underlined product related to the rate of disappearance of the underlined reactant?

5

reaction,

1

sec . If the rate

is 2.40  105 mollitre1 sec1, then the concentration of N2O5 (in mol liter–1) is : (A) 1.4 (C) 0.04

BrO3 (aq)  5Br  (aq)  6H    3Br 2 ()  3H 2 O()

VMC/Chemical Kinetics

(A)

if

two times on increasing the concentration of the reactant four times, then order of reaction is: (A) 0 (B) 2 (C) 1/2 (D) 4 5.

Unit of rate constant for zero order reaction is :

concentration of Cl2 is doubled, the rate becomes four times. What is the order of reaction? (A) 1 (B) 2 (C) 3 (D) 4

The reaction H   OH    H 2O is : (A) (C)

4.

(B)

22

(B) (D)

1.2 0.8

HWT/Chemistry

Vidyamandir Classes DATE :

TIME : 30 Minutes

MARKS : [ ___ /10]

TEST CODE : CHK [2]

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END TIME :

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 This test contains a total of 10 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking. Choose the correct alternative. Only one choice is correct. 1.

2.

The role of catalyst in a chemical reaction is to change : (A) Heat of reaction (C) Activation energy

(B) (D)

Decomposition of NH3 on the surface of tungsten is a reaction of : (A) zero order (B) first order (C)

Products of reaction Equilibrium constant

second order

(D)

fractional order.

3.

The ionic reactions are usually very fast because : (A) The energy of interaction between charged ions is greater than between neutral molecules (B) it does not involve bond breaking (C) the number of collisions between ions per unit volume per second are very large (D) these reactions are highly exothermic

4.

Which of the following explains the fact that the reactions of high molecularity are rare? (A) The more the number of colliding particles, the more is their weight and difficult it becomes to cross the barrier (B) The activation energy for many-body collisions becomes very large (C) Many-body collisions have low probability (D) Many body collisions are not energetically favoured

5.

On increasing the temperature by 10K, the rate of reaction becomes double. Which of the following is the most appropriate reason? (A) With increase of temperature, velocities increase and hence the number of collisions are appreciably increased. (B) The activation energy decreases with increase of temperature. (C) The bonds between the atoms of the reacting molecules become weak at higher temperatures. (D) The higher the temperature, large is the fraction of colliding particles which can cross the energy barrier

6.

In the presence of a catalyst, the heat evolved or absorbed during reaction : (A) decreases (B) increases (C) remains unaffected (D)

7.

may increase or decrease

If k1  rate constant at temperature T1 and k2 = rate constant at temperature T2 for a first order reaction, then which the following relations is correct? (Ea : activation energy)

8.

(A)

k 2.303 E a  T2  T1  log 1    k2 R  T1T2 

(B)

k E a  T2  T1  log 2    k1 2.303R  T1T2 

(C)

k E a  T1T2  log 2    k1 2.303R  T2  T1 

(D)

k E a  T1T2  log 1    k 2 2.303R  T2  T1 

A catalyst : (A) increases the average kinetic energy of the reacting molecules (B) decreases the value of enthalpy change in the reaction (C) reduces the time required for reaching the equilibrium state in the reaction (D) decreases the rate of reverse reaction

VMC/Chemical Kinetics

23

HWT/Chemistry

Vidyamandir Classes 9.

Diazonium salt decomposes as : C6 H 5 N 2 Cl   C6 H 5Cl  N 2 At 0oC, the evolution of N2 becomes two times faster when the initial concentration of the salt is doubled. Therefore, it is (A) a first order reaction (B) a second order reaction (C) independent of the initial concentration of the salt (D) a zero order reaction

10.

Which of the following statement is not correct for order of a reaction? (A) Order of a reaction can be determined experimentally (B) It is the sum of the powers of concentration terms in the rate law expression. (C) It does not necessarily depend on the stoichiometric coefficients. (D) Order of a reaction cannot be fractional

VMC/Chemical Kinetics

24

HWT/Chemistry

Vidyamandir Classes DATE :

TIME : 30 Minutes

MARKS : [ ___ /10]

TEST CODE : CHK [3]

START TIME :

END TIME :

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 This test contains a total of 10 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking. Choose the correct alternative. Only one choice is correct. 1.

For a given reaction of first order, it takes 20 minutes for the concentration to drop from 1.0M lit–1 to 0.6 M lit–1. The time required for the concentration to drop from 0.6 M lit–1 to 0.36 M lit–1 will be: (A) more than 20 minutes (B) less than 20 minutes (C) equal to 20 minutes (D) infinity

2.

75% of the first order reaction was completed in 32 min. 50% of the reaction was completed in : (A) 24 min. (B) 8 min. (C) 16 min. (D) 4 min.

3.

When ethyl acetate was hydrolysed in presence of 0.1 N HCl, the rate constant was found to be

6.

The rate of a gaseous reaction is given by the expression k [A][B]. If the volume of the reaction vessel is suddenly reduced to 1/4th of the initial volume, the reaction rate relating to original rate will be : (A) 1/10 (B) 1/8 (C) 8 (D) 16.

7.

For an endothermic reaction, where H represents the enthalpy of the reaction in kJ/mol, the minimum value for the energy of activation will be : (A) less than H (B) zero (C) more than H (D) equal to H

8.

In the first order reaction, 75% of the reactant disappeared in 1.388h. Calculate the rate constant of the reaction :

5.40  10s 1. But when 0.1 N H 2SO 4 was used for the hydrolysis, the rate constant was found to be 6.20  10s 1. From these values we can say that : (A) H 2SO 4 is stronger than HCl

4.

(B)

H 2SO 4 is weaker than HCl

(C) (D)

Both the acids have equal strength The data is insufficient to compare the strengths of HCl and H 2SO 4 .

9.

The amount of 53 I128 ( t1/ 2  25 minutes) left after 50 minutes will be : (A) 1/4 (B) 1/2 (C) 1/3 (D) None of these

(B)

2.8  10 4 s 1

(C)

17.2  103 s 1

(D)

1.8  103 s 1 k

1  In the reversible reaction : 2NO 2  N 2O 4 ; the

k2

(A)

2k1 2 NO 2  k2 

(B)

2k1[NO 2 ]2  2k 2 [N 2 O 4 ]

(C)

2k1  NO 2   k 2  N 2O 4 

(D)

The half life of a first order reaction is 10 minutes. If initial amount is 0.08 mole/litre and concentration at some instant is 0.01 mol/litre, then the value of t is : (A) 10 min. (B) 30 min. (C) 20 min. (D) 40 min.

VMC/Chemical Kinetics

3.6  10 3 s 1

rate of disappearance of NO 2 is equal to :

10. 5.

(A)

2

 2k1  k 2 NO2 

The rate constant, the activation energy and the Arrhenius parameter of a chemical reaction at 25oC are and 3.0  104 s 1, 104.4 kJ mol1, 6.0  1014 s 1 respectively. The value of the rate constant as

T    is:

25

(A)

2.0  1018 s 1

(B)

6.0  1014 s 1

(C)

Infinity

(D)

3.6  1030 s 1

HWT/Chemistry

Vidyamandir Classes DATE :

TIME : 30 Minutes

MARKS : [ ___ /10]

TEST CODE : CHK [4]

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 This test contains a total of 10 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking. Choose the correct alternative. Only one choice is correct. 1.

For the first order reaction with rate constant k, which expression gives the half-life period? (initial concentration = a) (A)

2.

6.

T

(B)

Z

(C)

E

(D)

p

1 and 3

(B)

2 and 3

(C)

1 and 4

(D)

2 and 4

first order reaction (B)

second order reaction (C)

third order reaction (D)

None of these

plotting substrate-time graph

(B)

plotting rate-time graph

calculating rate constants at two different temperatures

(D)

none of these

Rate constant depends on : temperature

(B)

time

(C)

initial concentration (D)

none

If the half-life for a reaction is 4 min, then the time after which the reaction is 99.9% completed is : 16 min

(B)

8 min.

(C)

32 min

(D)

40 min.

If `I’ is the intensity of absorbed light and `C’ is the concentration of AB for the photochemical process AB  hv  AB*, the rate of formation of AB* is directly proportional to : C

(B)

I

(C)

I2

(D)

C.I.

For the reaction A  B   C  D, doubling the concentration of both the reactants increases the reaction rate by 8 times and doubling the concentration of only B simply doubles the reaction rate. The rate law is given as : (A)

10.

3/2 ka2

(C)

(A) 9.

(D)

(A)

(A) 8.

0.693/ka

Activation energy of a reaction is determined by :

(A) 7.

(C)

The reaction 2FeCl3  SnCl2   2FeCl2  SnCl4 is an example of : (A)

5.

1/ka

The temperature coefficient of most of the reactions lies between : (A)

4.

(B)

The rate constant is given by the equation k  p.Ze  E / RT . Which factor should register a decrease for the reaction to proceed more rapidly? (A)

3.

ln 2/k

1/ 2

r  k A 

1/ 2

B

(B)

2

2

r  k A  B

(C)

r  k A  B

(D)

r  k A  B

ln A

(C)

ln K

(D)

log10a

In Arrhenius plot, intercept is equal to : (A)

Ea / R

VMC/Chemical Kinetics

(B)

26

HWT/Chemistry

Vidyamandir Classes DATE :

TIME : 30 Minutes

MARKS : [ ___ /10]

TEST CODE : CHK [5]

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 This test contains a total of 10 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking. Choose the correct alternative. Only one choice is correct. 1.

2.

When a biochemical reaction is carried out in laboratory from outside of human body in absence of enzyme then the rate of reaction obtained is 10–6 times, then activation energy of reaction in presence of enzyme is : (A) 6/RT (B) P is required (C) different from Ea obtained in the laboratory (D) cannot say anything 3A  2B, rate of reaction 

(A) (C) 3.

4.

5.

6.

3 d A  2 dt 1 d A  3

dt

d B dt

7.

(D)

2 d A  3 dt d A  2   dt



8.

The time taken for 90% of a first order reaction to complete is approximately : (A) 1.1 times that of half-life (B) 2.2 times that of half-life (C) 3.3 times that of half-life (D) 4.4 times that of half-life Consider

the

chemical

(B)

Rate = – d [N2]/dt = –3 d [H2]/dt = 2 d [NH3]/dt

(C)

Rate = – d [N2]/dt = 1/3 d [H2]/dt = 1/2 d [NH3]/dt

(D)

Rate = – d [N2]/dt = – d [H2]/dt = d [NH3]/dt

In a first order reaction, the concentration of the reactant

(A)

2  104

(B)

3.45  105

(C)

1.386  10 4

(D)

2  10 4

The potential diagram for reaction R  P is given below: H of the reaction corresponds to the energy

A chemical reaction was carried out at 300 K and 280 K. The rate constants were found to be K1 and K2 respectively. Then : (A) K2 = 4K1 (B) K2 = 2K1 (C) K2 = 0.25K1 (D) K2 = 0.5K1 Collision Theory is applicable to : (A) First order reactions (B) Zero order reactions (C) Bimolecular reactions (D) Intramolecular reactions

Rate = – d [d2]/dt = – 1/3 d [H2]/dt = 1/2 d [NH3]/dt

decreases from 800 mol/dm3 to 50 mol/dm3 in 2  104 sec. The rate constant of the reaction in sec–1 is :

is equal to :

(B)

(A)

b (A)

ca

(B)

b

(C)

bc

(D)

cb

c

R a P

9.

The reaction A  B follows first order kinetics. The time taken for 0.8 mole of A to produce 0.6 mole of B is 1 hour. What is the time taken for conversion of 0.9 mole of A to produce 0.67 mole of B? (A) 1 hour (B) 0.5 hour (C) 0.25 hour (D) 2 hours

10.

DDT on exposure to water decomposes. Half-life = 10 years. How much time will it take for its 90% decomposition? (A) 50 years (B) 70 years (C) 500 years (D) 700 years

reaction,

N 2  g   3H 2  g    2NH3  g  . The rate of this reaction can be expressed in terms of time derivate of concentration of N 2  g  ,H 2  g  or NH3  g  , Identify the correct relationship amongst the rate expressions :

VMC/Chemical Kinetics

27

HWT/Chemistry

Vidyamandir Classes DATE :

TIME : 30 Minutes

MARKS : [ ___ /10]

TEST CODE : CHK [6]

START TIME :

END TIME :

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 This test contains a total of 10 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking. Choose the correct alternative. Only one choice is correct. 1.

2.

3.

6.

The half-life of a reaction is halved as the initial concentration of the reactant is doubled. The order of reaction is : (A) 0.5 (B) 1 (C) 2 (D) 0 The rate constant of the reaction at temperature 200 K is 10 times less than the rate constant at 400 K. What is the activation energy of the reaction? (A) 1842.4 R (B) 921.2R (C) 460.6 R (D) 230.3 R

7.

In the reaction 2A  B  A 2B, if the concentration of 8.

The rate constant k, for the reaction 1 N 2O5  g    2NO 2  g   O 2  g  is 2.3  10 2 s 1. 2 Which equation given below describes the change of N 2O5  with time? N 2O5 0 and N 2O5  t correspond

5.

N 2O5 0  N 2O5 t ekt

(C)

log N 2O5 t  log N 2O5 0  kt

(D)

ln

The

rate 2

N 2O5 0 N 2O5 t

of 1

a

1.5  10 mol L min

first 1

order

reaction

1.73  104 M / min (B)

3.47  105 M / min

(C)

3.47  104 M / min (D)

1.73  105 M / min

The

reaction

 2SO3  g  2SO 2  g   O 2  g  

is

 C is The rate equation for the reaction 2A  B  found to be : rate = k [A][B]. The correct statement in relation to this reaction is : (A)

unit of k must be s 1

(B)

t1 / 2 is constant

(C)

rate of formation of C is twice the rate of disappearance of A value of k is independent of the initial concentration of A and B

(D)

to the concentration of N2O5 initially and at time t ? (A) N 2O5 t  N 2O5 0  kt (B)

(A)

carried out in 1 dm3 vessel and 2 dm3 vessel separately. The ratio of the reaction velocities will be : (A) 1:8 (B) 1:4 (C) 4:1 (D) 8:1

A is doubled and that of B is halved, then the rate of reaction will: (A) increase by 4 times (B) decrease by 2 times (C) increase by 2 times (D) remain the same 4.

The reaction X  product follows first order kinetics. In 40 minutes, the concentration of X changes from 0.1 M to 0.025 M, then the rate of reaction when concentration of X is 0.01 M is :

is

at 0.5 M concentration of the

9.

The half-lives of two samples are 0.1 and 0.4 second. Their respective concentrations are 200 and 50 respectively. What is the order of the reaction? (A) 0 (B) 2 (C) 1 (D) 4

10.

The activation energy for most of the reactions is approximately 50 kJ mol–1. The value of temperature coefficient for such reactions is : (A) approx 2 (B) approx 3 (C) 4

reactant. The half-life of the action is : (A) 0.383 min (B) 23.1 min (C) 8.73 min (D) 7.53 min

VMC/Chemical Kinetics

28

HWT/Chemistry

Vidyamandir Classes DATE :

TIME : 30 Minutes

MARKS : [ ___ /10]

TEST CODE : CHK [7]

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END TIME :

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 This test contains a total of 10 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking. Choose the correct alternative. Only one choice is correct. 1.

For the reaction : 2A  B   C  D, measurement of the rate of the reaction at varying concentrations are given below: Trial No. [A] [B] Rate (m mol L–1s–1) 1 0.010 0.010 2.5 2 0.010 0.020 5.0 3 0.030 0.020 45.0

2.

A substance undergoes first order decomposition. The decomposition follows two parallel first order reactions as : 4 1

; k 2  3.8  10 s The percentage distribution of B and C are : (A) 75% B and 25% C (C) 60% B and 40% C

A C

k2 (B) (D)

80% B and 20% C 76.83% B and 23.17% C

For reaction a A   xP , when [A] = 2.2 mM, the rate was found to be 2.4 mMs–1. On reducing the concentration of A to half, the rate changes to 0.6 mMs–1. The order of reaction with respect to A is : (A) 1.5 (B) 2.0 (C)

4.

B

5 1

k1  1.26  10 s

3.

k1

2.5

(D)

3.0

t1/ 4 can be taken as the time taken for the concentration of a reactant to drop to 3/4 of its initial value. If the rate constant for a

first order reaction is K, then t1/ 4 can be written as : (A) 5.

6.

7. 8.

9.

(B)

0.29/K

(C)

0.69/K

(D)

0.75/K

The rate of reaction between two reactants A and B decreases by a factor of 4 if the concentration of reactant B is doubled. The order of this reaction with respect to the reactant B is : (A) 2 (B) –1 (C) 1 (D) –2 For a first order reaction A   B , the reaction rate at reactant concentration of 0.01 M is found to be 2.0  105 mol L1s 1. The half-life of the reaction is : (A) 300 s (B) 30 s (C) 220 s (D) 347 s The rate constant of a chemical reaction has units L mol–1s–1. Order of the reaction will be : (A) 0 (B) 1 (C) 2

(D)

3

Which of the following reactions ends in finite time? (A) 0 order (B) 1st order

(D)

3rd order

(C)

2nd order

d A  d B A  2B   C  D. If     5  104 mol L1s 1, then    is : dt dt (A)

10.

0.10/K

2.5  104 mol L1s 1 (B)

5.0  104 mol L1s 1

(C)

2.5  103 mol L1s 1 (D)

1.0  103 mol L1s 1

The rate law for a reaction between the substances A and B is given by : Rate = k [A]n[B]m On doubling the concentration of A and halving the concentration of B, the ratio of the new rate to the earlier rate of the reaction will be: (A)

m+n

VMC/Chemical Kinetics

(B)

(n – m)

(C)

29

2(n – m)

(D)

1

mn  2

HWT/Chemistry

Vidyamandir Classes DATE :

TIME : 30 Minutes

MARKS : [ ___ /10]

TEST CODE : CHK [8]

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 This test contains a total of 10 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking. Choose the correct alternative. Only one choice is correct. 1.

 4NO 2  O 2 . For the above reaction which of the following is not correct about rates of reaction? 2N 2O5  (A) (C)

2.

d N 2O5 

d O 2  2   dt dt d NO 2  d O 2  4 dt dt

(B) (D)

2d N 2O5  dt

d O 2  2   dt

2d[N 2O5 ] d[NO 2 ] d[O 2 ]   dt dt dt

For the reaction, Cl2  2I    I 2  2Cl , the initial concentration of I  was 0.20 mol L1 . Then the rate of formation of

I 2 in mol L1 would be: (A) 3.

(B)

5  104

(C)

d(B) is equal to : dt 2 d[A] (C)  3 dt

1  103

(D)

5  103

2d[A] dt

(D)



In the reaction 3A   2B , rate of reaction  (A)

4.

1  104



1 d[A] 3 dt

(B)



3 d[A] 2 dt

 2NH3 For the reaction, N 2  3H 2 

The rate of change of concentration for hydrogen is 0.3  104 Ms 1 . The rate of change of concentration of ammonia is : (A) 5.

0.2  104

0.2  104

(C)

0.1  104

(D)

0.3  104

 2SO3 (g) is carried out in a 1dm3 vessel and 2dm3 vessel separately. The ratio of the The reaction, 2SO 2 (g)  O 2 (g)  reaction velocities will be : (A) 1 :8

6.

(B)

For the reaction,

(B)

1:4

(C)

4 :1

(D)

8:1

2N 2O5 (g)   4NO 2 (g)  O 2 (g)

If the concentration of NO2 increases by 5.2  103 M in 100s then the rate of the reaction is : (A) 7.

1.3  105 Ms 1

(B)

0.5  104 Ms 1

(C)

7.6  104 Ms 1

2  104 Ms 1

Observe the following reaction, 2A  B  C The rate of formation of C is 2.2  103 Mol1 min 1 . What is the value of 

2.2  103

d[A] (in mol L1 min 1) ? dt

1.1  103

(C)

4.4  103

The rate of chemical reaction : (A) increases as the reaction proceeds (C) may increase or decrease during reaction

(B) (D)

decreases as the reaction proceeds remains constant as the reaction proceeds

(A) 8.

(D)

VMC/Chemical Kinetics

(B)

30

(D)

5.5  103

HWT/Chemistry

Vidyamandir Classes 9.

The following data were obtained during the first order decomposition of 2A(g)   B(g)  C(s) at a constant volume and at a particular temperature. S. No.

Time

Total pressure in Pascal

1

At the end of 10 min

300

2

After completion

200

The rate constant in min–1 is: (A) 10.

0.0693

(B)

69.3

(C)

The time required for 100% completion of a zero order reaction is : a (A) (B) (C) ak 2k

VMC/Chemical Kinetics

31

6.93

(D)

6.93  104

a k

(D)

2k a

HWT/Chemistry

Vidyamandir Classes DATE :

TIME : 30 Minutes

MARKS : [ ___ /10]

TEST CODE : CHK [9]

START TIME :

END TIME :

TIME TAKEN:

PARENT’S SIGNATURE :

 This test contains a total of 10 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking. Choose the correct alternative. Only one choice is correct. 1.

For a first order reaction, the concentration changes from 0.8 to 0.4 in 15 min. The time taken for the concentration to change from 0.1 M to 0.025 M is: (A) 30 min (B) 15 min (C) 7.5 min (D) 60 min

2.

CH3COOC2H5  H 2O   CH3COOH  C2H5OH is an example of .................order. (A) zero (B) second (C) third (D)

H

pseudo first order

3.

For a reaction between gaseous compounds, 2A  B   C  D ; the reaction rate law is as : rate  k[A][B] . If the volume of the container is made 1/4 of the initial, then what will be the rate of reaction as compared to the initial rate? 1 1 (A) 16 times (B) 4 times (C) times (D) times 8 16

4.

The half - life period of a first order chemical reaction is 6.93 min. The time required for the completion of 99% of the chemical reaction will be : (log 2 = 0.301) (A) 230.3 min (B) 23.03 min (C) 46.06 min (D) 460.6 min

5.

The unit of rate constant of a second order reaction is : (A)

6.

L2 / mol2s

(D)

per second

(C)

(D)

0.5 mol1dm 3

(B)

1.0mol dm 3

3

(B)

2

(C)

1.5mol dm 3

(D)

2.0 mol1dm3

d[C]  k[A][B] . Hence, the order of the reaction is : dt (C) 1 (D) 0

The rate law for a reaction between the substances A and B is given by rate =k [A]n[B]m. On doubling the concentration of A and halving the concentration of B, the ratio of the new rate to the earlier rate of the reaction will be as: (A)

10.

(B)

For a reaction, A  2B   C , rate is given by  (A)

9.

L2 / mol2s

Under the same reaction conditions, initial concentration of 1.386 mol dm 3 of a substance becomes half in 40 s and 20 s through k  first order and zero order kinetics respectively. Ratio  1  of the rate constants for first order (k1) and zero order (k0) of the  k0  reaction will be: (A)

8.

(C)

L / mol s

The plot between concentration versus time for a zero order reaction in represented by :

(A)

7.

(B)

1 2m n

(B)

(m  n)

(C)

(n  m)

(D)

2(n  m)

For the reaction system : 2NO(g)  O 2 (g)   2NO 2 (g) The volume is suddenly reduced to half its value by increasing the pressure on it. If the reaction is of first order with respect to O 2 and second order with respect to NO, the rate of reaction will: (A) diminish to one-fourth of its initial value (B) diminish to one - eighth of its initial value (C) increase to eight times of its initial value (D) increase to four times of its initial value

VMC/Chemical Kinetics

32

HWT/Chemistry

Vidyamandir Classes DATE :

TIME : 30 Minutes

MARKS : [ ___ /10]

TEST CODE : CHK [10]

START TIME :

END TIME :

TIME TAKEN:

PARENT’S SIGNATURE :

 This test contains a total of 10 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking. Choose the correct alternative. Only one choice is correct. 1.

For a first order reaction with rate constant 'k' and initial concentration 'a', the half-life period is given by: (A)

2.

ln 2 k

6.

(B)

mol1L1Ls 1

(B)

None of these

200 s

(C)

300 s

(D)

400 s

s 1

(C)

s

(D)

s 1mol L1

(D)

16.04  1011s

What is the two third life of a first order reaction having k  5.48  1014 s 1 ?

2.01  1011s

(B)

~ 2.01  1013 s

8.08  1013 s

(C)

A first order reaction is 75% complete after 32 min. When was 50% of the reaction completed? (A) 16 min (B) 8 min (C) 4 min (D)

32 min

In the reaction : 2N 2O5   4NO 2  O 2 , the initial pressure is 500 atm and rate constant k is 3.38  105 s 1 . After 10 min the final pressure of N 2O5 is : (A) 490 atm (B)

7.

(D)

2k . a 2

For the following homogeneous reaction, the unit of rate constant is : A  B  C

(A) 5.

3

(C)

k

(A) 4.

l ka

The rate constant of a first order reaction is 6.9  103 s 1 . How much time will it take to reduce the initial concentration to its 1/8th value? (A) 100 s

3.

(B)

250 atm

(C)

The activation energy of exothermic reaction A   B 80kJ mol

480 atm 1

(D)

420 atm

. The heat of reaction is 200 kJ mol1 . The activation energy

for the reaction B   A (in kJ mol1) will be : (A) 8.

80

(B)

120

10.

40

(D)

280

(D)

1500 K

For the two gaseous reactions, following data are given

A   B k1  1010 e 20,000 / T ;

9.

(C)

C   D k 2  1012 e 24,606 / T

the temperature at which k1 becomes equal to k2 is: (A) 400 K (B) 10000 K

(C)

800 K

Which increases on increase of temperature ? (A) Energy of activation (Ea) (C) Rate constant (k)

(B) (D)

Collision frequency (Z) Both (B) and (C)

The rate constant of a first order reaction at 27C is 103 min 1 . The temperature coefficient of this reaction is 2. What is the rate constant ( in min 1 ) at 17C for this reaction? (A)

103

VMC/Chemical Kinetics

(B)

5  104

(C)

33

2  103

(D)

102

HWT/Chemistry