# Chemical Kinetics Test 1

Total Questions:50 Total Time: 75 Min

Remaining:

## Questions 1 of 50

Question:The rate of a chemical reaction

Increases as the reaction proceeds

Decreases as the reaction proceeds

May increase or decrease during the reaction

Remains constant as the reaction proceeds

## Questions 2 of 50

Question:The rate of a reaction that not involve gases is not dependent on

Pressure

Temperature

Concentration

Catalyst

## Questions 3 of 50

Question:The rate at which a substance reacts depends on its

Atomic weight

Equivalent weight

Molecular weight

Active mass

## Questions 4 of 50

Question:The rate law for the reaction $$RCl + NaOH(aq) \to ROH + NaCl$$ is given by Rate $$= {K_1}[RCl]$$ . The rate of the reaction will be

Doubled on doubling the concentration of sodium hydroxide

Halved on reducing the concentration of alkyl halide to one half

Decreased on increasing the temperature of the reaction

Unaffected by increasing the temperature of the reaction

## Questions 5 of 50

Question:In the reaction $$2A + B \to {A_2}B$$, if the concentration of $$A$$ is doubled and of $$B$$ is halved, then the rate of the reaction will

Increase by four times

Decrease by two times

Increase by two times

Remain the same

## Questions 6 of 50

Question:The term $$\left( { - \frac{{dc}}{{dt}}} \right)$$ in a rate equation refers to the

Concentration of the reactant

Decrease in concentration of the reactant with time

Increase in concentration of the reactant with time

Velocity constant of the reaction

## Questions 7 of 50

Question:The rate of a reaction depends upon the

Volume

Force

Pressure

Concentration of reactant

## Questions 8 of 50

Question:For a given reaction $$3A + B \to C + D$$ the rate of reaction can be represented by

$$- \frac{1}{3}\frac{{d[A]}}{{dt}} = \frac{{ - d[B]}}{{dt}} = \frac{{ + d[C]}}{{dt}} = \frac{{ + d[D]}}{{dt}}$$

$$- \frac{1}{3}\frac{{d[A]}}{{dt}} = \frac{{d[C]}}{{dt}} = K{[A]^m}{[B]^n}$$

$$+ \frac{1}{3}\frac{{d[A]}}{{dt}} = \frac{{ - d[C]}}{{dt}} = K{[A]^n}{[B]^m}$$

None of these

## Questions 9 of 50

Question:The main function of a catalyst in speeding up a reaction is

To increase the rate of the forward reaction

To change the reaction path so as to decrease the energy of activation for the reaction

To reduce the temperature at which the reaction can occur

To increase the energy of the molecules of the reactants

## Questions 10 of 50

Question:The rate of a reaction

Increases with increase in temperature

Decreases with increase in temperature

Does not depend on temperature

Does not depend on concentration

## Questions 11 of 50

Question:Which of the following statements is false in relation to enzyme

pH affects their functioning

Temperature affects their functioning

They always increase activation energy

Their reactions are specific

## Questions 12 of 50

Question:For a reaction $$2A + B \to$$Products, doubling the initial concentration of both the reactants increases the rate by a factor of 8, and doubling the concentration of B alone doubles the rate. The rate law for the reaction is

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

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

$$\gamma = k[A][B]$$

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

## Questions 13 of 50

Question:For a reactions $$A + B \to$$product, it was found that rate of reaction increases four times if concentration of 'A' is doubled, but the rate of reaction remains unaffected. If concentration of 'B' is doubled. Hence, the rate law for the reaction is

$${\rm{rate}} = k[A][B]$$

$${\rm{rate}} = k{[A]^2}$$

$${\rm{rate}} = k{[A]^2}{[B]^1}$$

$${\rm{rate}} = k{[A]^2}{[B]^2}$$

## Questions 14 of 50

Question:Velocity constant K of a reaction is affected by

Change in the concentration of the reactant

Change of temperature

Change in the concentration of the product

None of the above

## Questions 15 of 50

Question:For the reaction $$2{N_2}{O_5} \to 4N{O_2} + {O_2}$$rate of reaction and rate constant are $$1.02 \times {10^{ - 4}}$$and $$3.4 \times {10^{ - 5}}{\sec ^{ - 1}}$$ respectively. The concentration of $${N_2}{O_5}$$ at that time will be

$$1.732$$

3

$$1.02 \times {10^{ - 4}}$$

$$3.4 \times {10^5}$$

## Questions 16 of 50

Question:The rate law of the reaction $$2{N_2}{O_5} \to 4N{O_2} + {O_2}$$ is

$$r = K[{N_2}{O_5}]$$

$$r = K{[{N_2}{O_5}]^2}$$

$$r = K{[{N_2}{O_5}]^0}$$

$$r = K{[N{O_2}]^4}[{O_2}]$$

## Questions 17 of 50

Question:If $$R = K{[NO]^2}[{O_2}],$$ rate constant may be increased by

Increasing temperature

Decreasing temperature

Increasing concentration of $${O_2}$$

Increasing concentration of $$NO$$

## Questions 18 of 50

Question:Which of the following is a first order reaction

$$N{H_4}N{O_2} \to {N_2} + 2{H_2}O$$

$$2HI$$$$\to$$$${H_2} + {I_2}$$

$$2N{O_2} \to 2NO + {O_2}$$

$$2NO + {O_2} \to 2N{O_2}$$

## Questions 19 of 50

Question:The inversion of cane sugar is represented by $${C_{12}}{H_{22}}{O_{11}} + {H_2}O \to {C_6}{H_{12}}{O_6} + {C_6}{H_{12}}{O_6}$$ It is a reaction of

Second order

Unimolecular

Pseudo unimolecular

None of the three

## Questions 20 of 50

Question:Which one of the following formula represents a first order reaction

$$K = \frac{x}{t}$$

$$K = \frac{1}{{2t}}\left[ {\frac{1}{{{{(a - x)}^2}}} - \frac{1}{{{a^2}}}} \right]$$

$$K = \frac{{2.303}}{t}{\log _{10}}\frac{a}{{(a - x)}}$$

$$K = \frac{1}{t}\,\frac{x}{{a(a - x)}}$$

## Questions 21 of 50

Question:The order of a reaction is said to be 2 with respect to a reactant X, when

The rate of the reaction is proportional to [X]

The rate of the reaction is proportional $${[X]^2}$$

Two molecules of X are present in the stoichiometric equation

The reaction occurs in two steps

## Questions 22 of 50

Question:Decay constant of a reaction is $$1.1 \times {10^{ - 9}}/\sec$$, then the half life of the reaction is

$$1.2 \times {10^8}$$

$$6.3 \times {10^8}$$

$$3.3 \times {10^8}$$

$$2.1 \times {10^8}$$

## Questions 23 of 50

Question:If the half life period of a reaction is inversely proportional to the initial concentration, the order of the reaction is

Zero

One

Two

Three

## Questions 24 of 50

Question:For the reaction $$2HI$$ $$\leftrightarrow$$$${H_2} + {I_2}$$, the rate of the reaction is proportional to $${[HI]^2}$$ . This means that the reaction is

Unimolecular

Bimolecular

Of first order

Of second order

## Questions 25 of 50

Question:Inversion of sucrose is

Zero order reaction

First order reaction

Second order reaction

Third order reaction

## Questions 26 of 50

Question:The one which is unimolecular reaction is

$$2HI \to {H_2} + {I_2}$$

$${N_2}{O_5} \to {N_2}{O_4} + \frac{1}{2}{O_2}$$

$${H_2} + C{l_2} \to 2HCl$$

$$PC{l_3} + C{l_2} \to PC{l_5}$$

## Questions 27 of 50

Question:The half life of a first order reaction is 10 minutes. If initial amount is $$0.08\,mol/litre$$ and concentration at some instant is $$0.01\,mol/litre$$, then $$t =$$

10 minutes

30 minutes

20 minutes

40 minutes

## Questions 28 of 50

Question:Half life period of second order reaction is

Proportional to the initial concentration of reactants

Independent of the initial concentration of reactants

Inversely proportional to initial concentration of reactants

Inversely proportional to square of initial concentration of reactants

## Questions 29 of 50

Question:The reaction $$2{H_2}{O_2} \to 2{H_2}O + {O_2}$$ is a

Zero order reaction

First order reaction

Second order reaction

Third order reaction

## Questions 30 of 50

Question:For the reaction $$A \to B$$ , the rate law expression is : Rate $$= \,k\,[A]$$ Which of the following statements is incorrect

The reaction is said to follow first order kinetics

The half life of the reaction will depend on the initial concentration of the reactant

$$k$$is constant for the reaction at a constant temperature

The rate law provides a simple way of predicting the concentration of reactants and products at any time after the start of the reaction

## Questions 31 of 50

Question:If initial concentration is reduced to its 1/4th in a zero order reaction, the time taken for half of the reaction to complete

Remains same

Becomes 4 times

Becomes one-fourth

Doubles

## Questions 32 of 50

Question:For a reaction whose rate expression is : Rate $$= k{[A]^{1/2}}{[B]^{3/2}}$$ , the order would be

1.5

2

3

1

## Questions 33 of 50

Question:For a reaction $$2NO(g) + C{l_2}(g)$$ $$\leftrightarrow$$$$\,2NOCl(g)$$ . When concentration of $$C{l_2}$$ is doubled, the rate of reaction becomes two times of the original. When the concentration of NO is doubled the rate becomes four times. What is the order of the reaction

1

2

3

4

## Questions 34 of 50

Question:The rate constant for a second order reaction is $$8 \times {10^{ - 5}}{M^{ - 1}}mi{n^{ - 1}}$$ . How long will it take a 1M solution to be reduced to 0.5 M

$$8 \times {10^{ - 5}}$$min

$$8.665 \times {10^3}$$min

$$4 \times {10^{ - 5}}$$min

$$1.25 \times {10^4}$$min

## Questions 35 of 50

Question:The rate for a first order reaction is $$0.6932 \times {10^{ - 2}}mol\,{l^{ - 1}}mi{n^{ - 1}}$$ and the initial concentration of the reactants is 1M, $${T_{1/2}}$$ is equal to

$$6.932$$min

100 min

$$0.6932 \times {10^{ - 3}}$$min

$$0.6932 \times {10^{ - 2}}$$min

## Questions 36 of 50

Question:If the order of the reaction $$x + y \to x\,y$$ is zero, it means that the rate of

Reaction is independent of temperature

Formation of activated complex is zero

Reaction is independent of the concentration of reacting species

Decomposition of activated complex is zero

## Questions 37 of 50

Question:For a first order reaction velocity constant, $$K = {10^{ - 3}}{s^{ - 1}}$$ . Two third life for it would be

1100 s

2200 s

3300 s

4400 s

## Questions 38 of 50

Question:In a reaction, the concentration of reactant is increased two times and three times then the increases in rate of reaction were four times and nine times respectively, order of reaction is

Zero

1

2

3

## Questions 39 of 50

Question:For a reaction, $$X(g) \to Y(g) + Z(g)$$ the half life period is 10 min. In What period of time would the concentration of X be reduced to 10% of original concentration

20 min

33 min

15 min

25 min

## Questions 40 of 50

Question:A first order reaction with respect to the reactant A has a rate constant of $$6\;{\sec ^{ - 1}}$$ . If we start with [A] = 0.5 mol/litre, then in what time the concentration of A becomes 0.05 mol/litre

0.384 sec

0.214 sec

3.84 sec

0.402 sec

## Questions 41 of 50

Question:Order of radioactive disintegration reaction is

Zero

First

Second

Third

## Questions 42 of 50

Question:The half-life of a first order reaction having rate constant K = 1.7 x 10$$^{ - 5}$$ s$$^{ - {\rm{1}}}$$ is

12.1 h

9.7 h

11.3 h

1.8 h

## Questions 43 of 50

Question:For the reaction $$A + B \to C$$, it is found that doubling the concentration of A increases the rate by 4 times, and doubling the concentration of B doubles the reaction rate. What is the overal order of the reaction.

4

3/2

3

1

## Questions 44 of 50

Question:Which of the following reactions end in finite time

0 order

1st order

2nd order

3rd order

## Questions 45 of 50

Question:The minimum energy a molecule should possess in order to enter into a fruitful collision is known as

Reaction energy

Collision energy

Activation energy

Threshold energy

## Questions 46 of 50

Question:Activation energy is

The amount of energy to be added to the actual energy of a molecule so that the threshold energy is reached

The amount of energy the molecule must contain so that it reacts

The energy which a molecule should have in order to enter into an effective collision

The average kinetic energy of the molecule

## Questions 47 of 50

Question:The reason for almost doubling the rate of reaction on increasing the temperature of the reaction system by $${10^{oC}}$$ is

The value of threshold energy increases

Collision frequency increases

The fraction of the molecule having energy equal to threshold energy or more increases

Activation energy decreases

## Questions 48 of 50

Question:The activation energy of a reaction is zero. The rate constant of this reaction

Increases with increase of temperature

Decreases with an increase of temperature

Decreases with decrease of temperature

Is independent of temperature

## Questions 49 of 50

Question:The rate constant is given by the equation $$k = pz{e^{ - E/RT}}$$. Which factor should register a decrease for the reaction to proceed more rapidly

$$T$$

$$Z$$

$$E$$

$$p$$

## Questions 50 of 50

Question:Consider an endothermic reaction $$X \to Y$$ with the activation energies $${E_b}$$ and $${E_f}$$ for the backward and forward reactions, respectively, in general

$${E_b} < {E_f}$$
$${E_b} > {E_f}$$
$${E_b} = {E_f}$$
There is no definite relation between $${E_b}$$and $${E_f}$$