# Chemical Kinetics Test 3

Total Questions:50 Total Time: 75 Min

Remaining:

## Questions 1 of 50

Question:Time required for completion of ionic reactions in comparison to molecular reactions is

Maximum

Minimum

Equal

None

## Questions 2 of 50

Question:For reaction $$2A + B \to$$ products, the active mass of B is kept constant and that of A is doubled. The rate of reaction will then

Increase 2 times

Increase 4 times

Decrease 2 times

Decrease 4 times

## Questions 3 of 50

Question:In a reaction $$2A + B \to {A_2}B$$, the reactant A will disappear at

Half the rate that B will decrease

The same rate that B will decrease

Twice the rate that B will decrease

The same rate that $${A_2}B$$ will form

## Questions 4 of 50

Question:An increase in temperature by $${10^o}C$$, generally increases the rate of a reaction by

5 times

10 times

9 times

100 times

## Questions 5 of 50

Question:The temperature coefficient for reaction in which food deteriorates is 2. Then food deteriorates ...... times as rapidly at $${25^o}C$$ as it does at $${5^o}C$$

Two

Four

Six

Twenty

## Questions 6 of 50

Question:The rate of a reaction is doubled for every $${10^o}$$ rise in temperature. The increase in reaction rate as a result of temperature rise from $${10^o}$$ to $${100^o}$$ is

112

512

400

614

## Questions 7 of 50

Question:Which of these does not influence the rate of reaction

Nature of the reactants

Concentration of the reactants

Temperature of the reaction

Molecularity of the reaction

## Questions 8 of 50

Question:The rate law for reaction $$A + 2B = C + 2D$$ will be

Rate $$= K[A]\,[B]$$

Rate $$= K[A]\,[2B]$$

Rate $$= K[A]\,{[B]^2}$$

Rate $$= K\frac{{[C]{{[D]}^2}}}{{[A]{{[B]}^2}}}$$

## Questions 9 of 50

Question:In the reaction $$2{N_2}{O_5} \to 4N{O_2} + {O_2}$$, initial pressure is $$500\,atm$$and rate constant $$K$$is $$3.38 \times {10^{ - 5}}{\sec ^{ - 1}}$$. After 10 minutes the final pressure of $${N_2}{O_5}$$ is

490 atm

250 atm

480 atm

420 atm

## Questions 10 of 50

Question:The rate of reaction is determined by slow step reaction. The step is called

Reaction rate

Activation step

Rate determining step

None of the above

## Questions 11 of 50

Question:The rate of the reaction $$CC{l_3}CHO + NO \to CHC{l_3} + NO + CO$$is given by Rate $$= K\,[CC{l_3}CHO]\,[NO]$$. If concentration is expressed in moles/litre, the units of K are

$$litr{e^2}\,mol{e^{ - 2}}\,{\sec ^{ - 1}}$$

$$mole\,litr{e^{ - 1}}{\sec ^{ - 1}}$$

$$litre\,mol{e^{ - 1}}{\sec ^{ - 1}}$$

$${\sec ^{ - 1}}$$

## Questions 12 of 50

Question:Rate constant for a reaction $${H_2} + {I_2} \to 2HI$$ is 49, then rate constant for reaction $$2HI \to {H_2} + {I_2}$$ is

7

1/49

49

21

63

## Questions 13 of 50

Question:A zero order reaction is one whose rate is independent of

Temperature of the reaction

The concentrations of the reactants

The concentration of the products

The material of the vessel in which the reaction is carried out

## Questions 14 of 50

Question:The unit of rate constant for a zero order reaction is

litre $${\sec ^{ - 1}}$$

litre $$mol{e^{ - 1}}\,{\sec ^{ - 1}}$$

mole $$litr{e^{ - 1}}{\sec ^{ - 1}}$$

mole $${\sec ^{ - 1}}$$

## Questions 15 of 50

Question:Which of the following rate laws has an overall order of 0.5 for reaction involving substances $$x$$, $$y$$ and $$z$$

Rate $$= K({C_x})\,({C_y})\,({C_z})$$

Rate $$= K{({C_x})^{0.5}}\,{({C_y})^{0.5}}\,{({C_z})^{0.5}}$$

Rate $$= K{({C_x})^{1.5}}\,{({C_y})^{ - 1}}{({C_z})^0}$$

Rate $$= K({C_x})\,{({C_z})^n}/{({C_y})^2}$$

## Questions 16 of 50

Question:Catalyst decomposition of hydrogen peroxide is a ........ order reaction

First

Second

Third

Zero

## Questions 17 of 50

Question:The half life of a first order reaction is

Independent of the initial concentration of the reactant

Directly proportional to the initial concentration of the reactants

Inversely proportional to the initial concentration of the reactant

Directly proportional to the square of the initial concentration of the reactant

## Questions 18 of 50

Question:The decomposition of $${N_2}{O_5}$$ is a first order reaction represented by $${N_2}{O_5} \to {N_2}{O_4} + \frac{1}{2}{O_2}$$. After 15 minutes the volume of $${O_2}$$ produced is $$9\,ml$$ and at the end of the reaction $$35\,ml$$. The rate constant is equal to

$$\frac{1}{{15}}\,\ln \,\frac{{35}}{{44}}$$

$$\frac{1}{{15}}\,\ln \,\frac{{44}}{{26}}$$

$$\frac{1}{{15}}\,\ln \,\frac{{44}}{{35}}$$

$$\frac{1}{{15}}\,\ln \,\frac{{35}}{{26}}$$

## Questions 19 of 50

Question:The unit of specific reaction rate constant for a first order (if the concentration expressed in molarity) would be

mole $$litr{e^{ - 1}}{s^{ - 1}}$$

mole $$litr{e^{ - 1}}$$

mole $${s^{ - 1}}$$

$${s^{ - 1}}$$

## Questions 20 of 50

Question:The time of half change of a first order reaction in ....... initial concentration

Proportional to

Inversely proportional to

Independent of

Equal to

## Questions 21 of 50

Question:Half life period of a first order reaction is 138.6 minutes. The velocity constant of the reaction is

$$0.05\,{\min ^{ - 1}}$$

$$0.00005\,{\min ^{ - 1}}$$

$$0.005\,{\min ^{ - 1}}$$

$$200\,{\min ^{ - 1}}$$

## Questions 22 of 50

Question:An example of a pseudo-unimolecular reaction is

Dissociation of hydrogen iodide

Hydrolysis of methyl acetate in dilute solution

Dissociation of phosphorus pentachloride

Decomposition of hydrogen peroxide

## Questions 23 of 50

Question:About half life period of a first order reaction, which one of the following statements is generally false

It is independent of initial concentration

It is independent of temperature

It decreases with the introduction of a catalyst

It increases with increase of temperature

## Questions 24 of 50

Question:The unit of the velocity constant in case of zero order reaction is

$$Conc. \times tim{e^{ - 1}}$$

$$Conc{.^{ - 1}} \times time$$

$$Conc{.^{ - 1}} \times tim{e^{ - 1}}$$

$$Conc. \times {(time)^2}$$

## Questions 25 of 50

Question:For the reaction $${H_2}(g) + B{r_2}(g) \to 2HBr(g)$$, the experimental data suggest, rate $$= K[{H_2}]{[B{r_2}]^{1/2}}$$. The molecularity and order of the reaction are respectively

$$2,\,\frac{3}{2}$$

$$\frac{3}{2},\,\frac{3}{2}$$

1, 1

$$1,\,\frac{1}{2}$$

## Questions 26 of 50

Question:Which of the following statements regarding the molecularity of a reaction is wrong

It is the number of molecules of the reactants taking part in a single step chemical reaction

It is calculated from the reaction mechanism

It may be either a whole number or fractional

It depends on the rate determining step in the reaction

## Questions 27 of 50

Question:Diazonium salt decomposes as $${C_6}{H_5}N_2^ + C{l^ - } \to {C_6}{H_5}Cl + {N_2}$$. At $${0^o}C$$, the evolution of $${N_2}$$ becomes two times faster when the initial concentration of the salt is doubled. Therefore, it is

A first order reaction

A second order reaction

Independent of the initial concentration of the salt

A zero order reaction

## Questions 28 of 50

Question:The rate constant of a first order reaction whose half-life is 480 seconds, is

$$2.88 \times {10^{ - 3}}{\sec ^{ - 1}}$$

$$1.44 \times {10^{ - 3}}{\sec ^{ - 1}}$$

$$1.44\,{\sec ^{ - 1}}$$

$$0.72 \times {10^{ - 3}}{\sec ^{ - 1}}$$

## Questions 29 of 50

Question:The conversion of $$A \to B$$ follows second order kinetics. Doubling the concentration of $$A$$ will increase the rate of formation of $$B$$ by a factor

$$1/4$$

2

$$1/2$$

4

## Questions 30 of 50

Question:The reaction $$2FeC{l_3} + SnC{l_2} \to 2FeC{l_2} + SnC{l_4}$$ is an example of

First order reaction

Second order reaction

Third order reaction

None of these

## Questions 31 of 50

Question:If reaction between $$A$$ and $$B$$ to give $$C$$ shows first order kinetics in $$A$$ and second order in $$B$$ , the rate equation can be written as

Rate $$= k\,[A]\,{[B]^{1/2}}$$

Rate $$= k{[A]^{1/2}}[B]$$

Rate $$= k\,[A]\,{[B]^2}$$

Rate $$= k{[A]^2}[B]$$

## Questions 32 of 50

Question:The rate law of the reaction $$A + 2B \to$$ Product is given by $$\frac{{d[dB]}}{{dt}} = k[{B^2}]$$. If A is taken in excess, the order of the reaction will be

1

2

3

0

## Questions 33 of 50

Question:For a first order reaction $$A \to$$ product, the rate of reaction at $$[A] = 0.2\,\,mol\,\,{l^{ - 1}}$$ is $$1.0 \times {10^{ - 2}}mol\,\,{l^{ - 1}}\, {\min ^{ - 1}}$$. The half life period for the reaction is

832 s

440 s

416 s

13.86 s

## Questions 34 of 50

Question:For the reaction $$A + B \to$$ products, doubling the concentration of A the rate of the reaction is doubled, but on doubling the concentration of B rate remains unaltered. The over all order of the reaction is

1

0

2

3

## Questions 35 of 50

Question:Which among the following is a false statement

Half life of a third order reaction is inversely proportional to the square of initial concentration of the reactant.

Molecularity of a reaction may be zero or fractional

For a first order reaction $${t_{1/2}} = \frac{{0.693}}{K}$$

Rate of zero order reaction is independent of initial concentration of reactant

## Questions 36 of 50

Question:Order of a reaction is decided by

Pressure

Temperature

Molecularity

Relative concentration of reactants

## Questions 37 of 50

Question:From the following which is a second order reaction

$$K = 5.47 \times {10^{ - 4}}{\sec ^{ - 1}}$$

$$K = 3.9 \times {10^{ - 3}}{\rm{mole}}\,\,{\rm{lit}}\,\,{\sec ^{ - 1}}$$

$$K = 3.94 \times {10^{ - 4}}{\rm{lit}}\,\,{\rm{mol}}{{\rm{e}}^{{\rm{ - 1}}}}\,\,{\sec ^{ - 1}}$$

$$K = 3.98 \times {10^{ - 5}}{\rm{lit}}\,\,{\rm{mol}}{{\rm{e}}^{{\rm{ - 2}}}}\,\,{\sec ^{ - 1}}$$

## Questions 38 of 50

Question:For the reaction $$A + 2B \to C,$$ rate is given by R $$= [A]{[B]^2}$$ then the order of the reaction is

3

6

5

7

## Questions 39 of 50

Question:The reaction $$A \to B$$ 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 0.675 mole of B

hours

1 hour

0.5 hour

0.25 hour

## Questions 40 of 50

Question:The unit of velocity constant in case of zero order reaction is

Concentration$$\times {\rm{Tim}}{{\rm{e}}^{ - 1}}$$

$${\rm{Concentratio}}{{\rm{n}}^{{\rm{ - 1}}}} \times {\rm{Tim}}{{\rm{e}}^{{\rm{ - 1}}}}$$

$${\rm{Concentration}} \times {\rm{Tim}}{{\rm{e}}^{\rm{2}}}$$

$${\rm{Concentratio}}{{\rm{n}}^{{\rm{ - 1}}}} \times {\rm{Time}}$$

## Questions 41 of 50

Question:Which one of the following is wrongly matched

Saponification of$$C{H_3}COO{C_2}{H_5}$$Second order reaction

Hydrolysis of $$C{H_3}COOC{H_3}$$Pseudo uni-molecular reaction

Decomposition of $${H_2}{O_2}$$First order reaction

Combination of $${H_2}$$and $$B{r_2}$$to give $$HBr$$Zero order reaction

## Questions 42 of 50

Question:For a first order reaction

The degree of dissociation is equal to $$(1 - {e^{ - kt}})$$

A plot of reciprocal concentration of the reactant vs time gives a straight line

The time taken for the completion of 75% reaction is thrice the $${t_{1/2}}$$of the reaction

The pre-exponential factor in the Arrhenius equation has the dimension of time $${T^{ - 1}}$$

1 and 4 are correct

## Questions 43 of 50

Question:For reaction a $$A \to x\;P$$, when $$[A] = 2.2\;mM$$, the rate was found to be $$2.4\;mM\;{s^{ - 1}}$$. On reducing concentration of A to half, the rate changes to $$0.6\;mM\;{s^{ - 1}}$$. The order of reaction with respect to A is

1.5

2

2.5

3

## Questions 44 of 50

Question:Which one of the following statement for order of reaction is not correct

Order can be determined experimentally.

Order of reaction is equal to sum of the powers of concentration terms in differential rate law.

It is not affected with the stoichiometric coefficient of the reactants.

Order cannot be fractional.

## Questions 45 of 50

Question:The number of collisions depend upon

Pressure

Concentration

Temperature

All the above

## Questions 46 of 50

Question:If $${E_f}$$ and $${E_r}$$ are the activation energies of forward and reverse reactions and the reaction is known to be exothermic, then

$${E_f} > {E_r}$$

$${E_f} < {E_r}$$

$${E_f} = {E_r}$$

No relation can be given between $${E_f}$$and $${E_r}$$as data are not sufficient

## Questions 47 of 50

Question:According to Arrhenius theory, the activation energy is

The energy it should possess so that it can enter into an effective collision

The energy which the molecule should possess in order to undergo reaction

The energy it has to acquire further so that it can enter into a effective collision

The energy gained by the molecules on colliding with another molecule

## Questions 48 of 50

Question:For a reaction, activation energy $$({E_a}) = 0$$ and rate constant $$(K) = 3.2 \times {10^6}{s^{ - 1}}$$at 300 K. What is the value of the rate constant at 310 K

$$3.2 \times {10^{ - 12}}{s^{ - 1}}$$

$$3.2 \times {10^6}{s^{ - 1}}$$

$$6.4 \times {10^{12}}{s^{ - 1}}$$

$$6.4 \times {10^6}{s^{ - 1}}$$

## Questions 49 of 50

Question:Activation energy is given by the formula

$$\log \frac{{{K_2}}}{{{K_1}}} = \frac{{{E_a}}}{{2.303R}}\left[ {\frac{{{T_2} - {T_1}}}{{{T_1}{T_2}}}} \right]$$

$$\log \frac{{{K_1}}}{{{K_2}}} = - \frac{{{E_a}}}{{2.303R}}\left[ {\frac{{{T_2} - {T_1}}}{{{T_1}{T_2}}}} \right]$$

$$\log \frac{{{K_1}}}{{{K_2}}} = - \frac{{{E_a}}}{{2.303R}}\left[ {\frac{{{T_1} - {T_2}}}{{{T_1}{T_2}}}} \right]$$

None of these

## Questions 50 of 50

Question:A reaction having equal activation energies for forward and reverse reaction has

$$\Delta H = 0$$
$$\Delta S = 0$$