# Chemical Kinetics Test 2

Total Questions:50 Total Time: 75 Min

Remaining:

## Questions 1 of 50

Question:When a reaction is progressing

The rate of the reaction goes on increasing

The concentration of the products goes on decreasing

The concentration of the reactants goes on decreasing

The reaction rate always remains constant

## Questions 2 of 50

Question:In a catalytic conversion of $${N_2}$$ to $$N{H_3}$$ by Haber's process, the rate of reaction was expressed as change in the concentration of ammonia per time is $$40 \times {10^{ - 3}}\,mol\,litr{e^{ - 1}}{s^{ - 1}}$$. If there are no side reaction, the rate of the reaction as expressed in terms of hydrogen is (in mol $$litr{e^{ - 1}}{s^{ - 1}}$$)

$$60 \times {10^{ - 3}}$$

$$20 \times {10^{ - 3}}$$

1.2

$$10.3 \times {10^{ - 3}}$$

## Questions 3 of 50

Question:If the concentration of the reactants is increased, the rate of reaction

Remains unaffected

Increases

Decreases

May increase or decrease

## Questions 4 of 50

Question:The rate of disappearance of $$S{O_2}$$ in the reaction $$2S{O_2} + {O_2} \to 2S{O_3}$$ is $$1.28 \times {10^{ - 3}}g/sec$$ then the rate of formation of $$S{O_3}$$ is

$$0.64 \times {10^{ - 3}}g/sec$$

$$0.80 \times {10^{ - 3}}g/sec$$

$$1.28 \times {10^{ - 3}}g/sec$$

$$1.60 \times {10^{ - 3}}g/sec$$

## Questions 5 of 50

Question:When the concentration of A in the reaction $$A + B$$$$\leftrightarrow$$$$AB$$ is doubled, the rate of reaction will be

Doubled

Decreased by half

Unchanged

Increased by four times

## Questions 6 of 50

Question:The velocity of the chemical reaction doubles every $${10^o}C$$ rise of temperature. If the temperature is raised by $${50^o}C$$, the velocity of the reaction increases to about

32 times

16 times

20 times

50 times

## Questions 7 of 50

Question:In which of the following cases, does the reaction go farthest to completion

$$K = {10^3}$$

$$K = {10^{ - 2}}$$

$$K = 10$$

$$K = 1$$

## Questions 8 of 50

Question:Rate of reaction

Decreases with increase in temperature

Increases with increase in temperature

May increase or decrease with increase in temperature

Does not depend on temperature

## Questions 9 of 50

Question:For the reaction $$2{N_2}{O_{5(g)}} \to 4N{O_{2(g)}} + {O_{2(g)}}$$, if concentration of $$N{O_2}$$ in 100 seconds is increased by $$5.2 \times {10^{ - 3}}m$$. Then rate of reaction will be

$$1.3 \times {10^{ - 5}}m{s^{ - 1}}$$

$$5 \times {10^{ - 4}}m{s^{ - 1}}$$

$$7.6 \times {10^{ - 4}}m{s^{ - 1}}$$

$$2 \times {10^{ - 3}}m{s^{ - 1}}$$

$$2.5 \times {10^{ - 5}}m{s^{ - 1}}$$

## Questions 10 of 50

Question:A first order reaction complete its 10% in 20 minutes then time required to complete its 19% is

30 minutes

40 minutes

50 minutes

38 minutes

45 minutes

## Questions 11 of 50

Question:For a reaction $$A \to B$$ the rate of reaction quadrupled when the concentration of A is doubled. The rate expression of the reaction is $$r = K{(A)^n}$$. when the value of $$n$$ is

1

0

3

2

## Questions 12 of 50

Question:The velocity constant of a reaction is K. Which of the following statements is not true regarding K

K is a constant for a reaction at a given temperature

The value of K changes when the temperature changes

K is the velocity of the reaction at unit concentrations of the reactant

K is a constant for all reactions

## Questions 13 of 50

Question:For the following reaction scheme (homogeneous), the rate constant has units : $$A + B \to C$$

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

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

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

sec

## Questions 14 of 50

Question:Which of the following oxides of nitrogen will be the most stable one

$$2N{O_2}(g)$$$$\leftrightarrow$$$${N_2}(g) + 2{O_2}(g);K = 6.7 \times {10^{16}}mol\,{l^{ - 1}}$$

$$2NO(g)$$$$\leftrightarrow$$ $${N_2}(g) + {O_2}(g);\,K = 2.2 \times {10^{30}}mol\,{l^{ - 1}}$$

$$2{N_2}{O_5}(g)$$$$\leftrightarrow$$$$2{N_2}(g) + 5{O_2}(g);\,K = 1.2 \times {10^{34}}\,mol\,{l^{ - 5}}$$

$$2{N_2}O(g)$$$$\leftrightarrow$$$$2{N_2}(g) + {O_2}(g);\,K = 3.5 \times {10^{33}}\,mol\,litr{e^{ - 1}}$$

## Questions 15 of 50

Question:The specific rate constant of a first order reaction depends on the

Concentration of the reactants

Concentration of the products

Time of reaction

Temperature of reaction

## Questions 16 of 50

Question:If the concentration is expressed in moles per litre, the unit of the rate constant for a first order reaction is

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

mole litre$$^{ - 1}$$

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

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

## Questions 17 of 50

Question:The dimension of rate constant of a second order reaction involves

Neither time nor concentration

Only time

Time and concentration

Time and square of concentration

## Questions 18 of 50

Question:The unit of rate constant of second order reaction is usually expressed as

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

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

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

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

## Questions 19 of 50

Question:The reaction $$2{N_2}{O_5}$$$$\leftrightarrow$$$$2N{O_2} + {O_2}$$ follows first order kinetics. Hence, the molecularity of the reaction is

Unimolecular

Pseudo–unimolecular

Bimolecular

None of the above

## Questions 20 of 50

Question:A reaction involving two different reactants

Can never be a second order reaction

Can never be a unimolecular reaction

Can never be a bimolecular reaction

Can never be a first order reaction

## Questions 21 of 50

Question:By "the overall order of a reaction", we mean

The number of concentration terms in the equation for the reaction

The sum of powers to which the concentration terms are raised in the velocity equation

The least number of molecules of the reactants needed for the reaction

The number of reactants which take part in the reaction

## Questions 22 of 50

Question:For a zero order reaction

The concentration of the reactant does not change during the reaction

The concentration change only when the temperature changes

The rate remains constant throughout

The rate of the reaction is proportional to the concentration

## Questions 23 of 50

Question:If 'a' is the initial concentration and 'n' is the order of the reaction and the half life period is 'T', then

$$T \propto {a^{n - 1}}$$

$$T \propto {a^n}$$

$$T \propto \frac{1}{{{a^n}}}$$

$$T \propto \frac{1}{{{a^{n - 1}}}}$$

## Questions 24 of 50

Question:In presence of $$HCl$$, sucrose gets hydrolysed into glucose and fructose. The concentration of sucrose was found to reduce form 0.4 M to 0.2 M in 1 hour and 0.1 M in 2 hours. The order of the reaction is

Zero

One

Two

None of these

## Questions 25 of 50

Question:Molecularity of reaction of inversion of sugar is

3

2

1

0

## Questions 26 of 50

Question:For any reaction, if we plot a graph between time 't' and $$\log (a - x)$$, a simple line is obtained. The order of reaction is

Zero

One

Two

Three

## Questions 27 of 50

Question:Value of velocity constant for first order reaction is $$3.46 \times {10^{ - 3}}{\min ^{ - 1}}$$, the time for half change is

100 minutes

400 minutes

200 minutes

346 minutes

## Questions 28 of 50

Question:If the rate expression for a chemical reaction is given by Rate $$= k{[A]^m}{[B]^n}$$

The order of the reaction is $$m$$

The order of the reaction is $$n$$

The order of the reaction is $$m + n$$

The order of the reaction is $$m - n$$

## Questions 29 of 50

Question:The half-life period of a first order reaction is 100 sec. The rate constant of the reaction is

$$6.93 \times {10^{ - 3}}{\sec ^{ - 1}}$$

$$6.93 \times {10^{ - 4}}{\sec ^{ - 1}}$$

$$0.693\,{\sec ^{ - 1}}$$

$$69.3\,{\sec ^{ - 1}}$$

## Questions 30 of 50

Question:For the first order reaction with rate constant $$k$$ , which expression gives the half-life period ? (Initial concentration $$= a$$ )

$$\frac{{{1^2}}}{k}$$

$$\frac{1}{{ka}}$$

$$\frac{{0.693}}{k}$$

$$\frac{3}{{2k{a^2}}}$$

## Questions 31 of 50

Question:The rate constant of a reaction is $$0.69 \times {10^{ - 1}}{\min ^{ - 1}}$$ and the initial concentration is $$0.2mol\,{l^{ - 1}}.$$ The half-life period is

400 sec

600 sec

800 sec

1200 sec

## Questions 32 of 50

Question:The rate constant of a first order reaction is $$3 \times {10^{ - 6}}$$per second. If the initial concentration is 0.10 m, the initial rate of reaction is

$$3 \times {10^{ - 5}}m{s^{ - 1}}$$

$$3 \times {10^{ - 6}}m{s^{ - 1}}$$

$$3 \times {10^{ - 8}}m{s^{ - 1}}$$

$$3 \times {10^{ - 7}}m{s^{ - 1}}$$

## Questions 33 of 50

Question:Certain bimolecular reactions which follow the first order kinetics are called

First order reactions

Unimolecular reactions

Bimolecular reactions

Pseudounimolecular reactions

## Questions 34 of 50

Question:A substance 'A' decomposes by a first order reaction starting initially with [A] =2.00m and after 200 min [A] = 0.15m. For this reaction what is the value of k

$$1.29 \times {10^{ - 2}}$$ min$$^{ - 1}$$

$$2.29 \times {10^{ - 2}}$$ min$$^{ - 1}$$

$$3.29 \times {10^{ - 2}}$$ min$$^{ - 1}$$

$$4.40 \times {10^{ - 2}}$$ min$$^{ - 1}$$

## Questions 35 of 50

Question:Which of the following statements about zero order reaction is not true

Its unit is $$se{c^{ - 1}}$$

The graph between log (reactant) versus rate of reaction is a straight line

The rate of reaction increases with the decrease in concentration of reactants

Rate of reaction is independent of concentration of reactants

1 and 3 are correct

## Questions 36 of 50

Question:The given reaction $$2NO + {O_2} \to 2N{O_2}$$ is an example of

First order reaction

Second order reaction

Third order reaction

None of these

## Questions 37 of 50

Question:Which equation is correct for first order reactions

$${t_{1/2}} \propto {C^{ - 1}}$$

$${t_{1/2}} \propto C$$

$${t_{1/2}} \propto {C^0}$$

$${t_{1/2}} \propto {C^{1/2}}$$

## Questions 38 of 50

Question:For the reaction system $$2NO(g) + {O_2}(g) \to 2N{O_2}(g)$$ volume is suddenly produced 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

Diminish to one fourth of its initial value

Diminish to one eighth of its initial value

Increase to eight times of its initial value

Increase to four times of its initial value

## Questions 39 of 50

Question:If the rate of the reaction is equal to the rate constant, the order of the reaction is

3

0

1

2

## Questions 40 of 50

Question:Decay of $$_{92}{U^{235}}$$ is .....order reaction

Zero

First

Second

Third

## Questions 41 of 50

Question:The half-life of 2 sample are 0.1 and 0.4 seconds. Their respective concentration are 200 and 50 respectively. What is the order of the reaction

0

2

1

4

## Questions 42 of 50

Question:The following statements(s) is(are) correct

A plot of $$\log \,{K_p}$$versus $$1/T$$is linear

A plot of $$\log \,[X]$$versus time is linear for a first order reaction $$X \to P$$

A plot of $$\log P$$versus $$1/T$$is linear at constant volume

A plot of $$P$$versus $$1/V$$is linear at constant temperature

1,2 and 4 are correct

## Questions 43 of 50

Question:According to the collision theory of reaction rates, rate of reaction increases with temperature due to

Greater number of collisions

Greater velocity of the reacting molecules

Greater number of molecules have activation energy

None of the above

## Questions 44 of 50

Question:The reaction rate at a given temperature becomes slower, then

The free energy of activation is higher

The free energy of activation is lower

The entropy changes

The initial concentration of the reactants remains constant

## Questions 45 of 50

Question:A rise in temperature increases the velocity of a reaction. It is because it results in

An increased number of molecular collisions

An increased momentum of colliding molecules

An increase in the activation energy

A decrease in the activation energy

## Questions 46 of 50

Question:Relation between rate constant and temperature by Arrhenius equation is

$${\log _e}A = {\log _e}K + \frac{{{E_a}}}{{RT}}$$

$$\log \,K = A\,\frac{{{E_a}}}{{RT}}$$

$${\log _e}K = {\log _e}A - \frac{{{E_a}}}{{R{T^2}}}$$

$$\log A = RT\,\ln \,{E_a} - \ln \,K$$

## Questions 47 of 50

Question:An endothermic reaction $$A \to B$$ has an activation energy $$15\,kcal/mole$$ and energy of reaction $$5\,kcal/mole$$. The activation energy of the reaction $$B \to A$$ is

20 kcal/mole

15 kcal/mole

10 kcal/mole

None of these

## Questions 48 of 50

Question:The Arrhenius equation expressing the effect of temperature on the rate constant of a reaction is

$$k = {e^{ - {E_a}/RT}}$$

$$k = {E_a}/RT$$

$$k = {\log _e}\,\frac{{{E_a}}}{{RT}}$$

$$k = A{e^{ - {E_a}/RT}}$$

## Questions 49 of 50

Question:The law of photochemical equivalence was given by

Drapper

Grauths

Einstein

Labbert

## Questions 50 of 50

Question:If 'I' is the intensity of absorbed light and C is the concentration of AB for the photochemical process $$AB + hv \to AB*,$$ the rate of formation of AB* is directly proportional to

$${I^2}$$