Consider the given plot of enthalpy of the following reaction between A and B . A + B → C + D . Identify the incorrect statement.

Activation enthalpy to form C is 5 k J m o l - 1 less than that to form D .

Formation of A and B from C has highest enthalpy of activation.

D is kinetically stable product.

C is the thermodynamically stable product.

HARD

Earn 100

Consider the following reaction that goes from $A$ to $B$ in three steps as shown below:

Choose the correct option

Number of
Intermediates Number of
Activated
Complexes Rate
determining
step

$(1)$ $2$ $3$ $I$

$(2)$ $2$ $3$ $III$

$(3)$ $2$ $3$ $II$

$(4)$ $3$ $2$ $II$

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Important Questions on Chemical Kinetics

EASY

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

An endothermic reaction

AB

has an activation energy as

x kJ / mol .

If the energy change of reaction is

y kJ,

the activation energy of the reverse reaction is

HARD

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

The highest peak in energy profile diagram for mechanism of alkaline hydrolysis of tertiary butyl bromide represents

EASY

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

The unit of activation energy is

EASY

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

For the equilibrium,

A (g) ⇌ B (g), ∆ H is - 40 kJ / mol

. If the ratio of the activation energies of the forward

(E_{f})

and reverse

(E_{b})

reactions is

\frac{2}{3}

then:

HARD

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

For the following reactions

A \overset{700 K}{\to} Product

A \overset{500 K}{\underset{catalyst}{\to}} Product

It was found that the

E_{a}

is decreased by

30 K J / m o l

in the presence of catalyst. If the rate remains unchanged, the activation energy for catalysed reaction is (Assume pre-exponential factor is same)

MEDIUM

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

Which of the following statements are not correct regarding rate of catalyst in a chemical reaction?
i. Changes the

ΔH

of the reaction
ii. Decrease the activation energy for the forward and backward reaction equally
iii. Provides a new path of higher activation energy
iv. Increases the average kinetic energy of reacting molecules

HARD

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

If the first order rate constants for the decomposition of ethyl iodide at

600 K

and

700 K

are

2.0 \times 10^{- 5} s^{- 1}

and

2.0 \times 10^{- 4} s^{- 1}

respectively, the activation energy for this reaction in

{kJmol}^{- 1}

EASY

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

In the presence of a catalyst, the heat evolved or absorbed during the reaction _____

MEDIUM

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

An endothermic reaction

A \to B

has an activation energy of

13 kJ {mol}^{- 1}

and the enthalpy change for the reaction is

2 kJ {mol}^{- 1}

. The activation energy of the reaction

B \to A

MEDIUM

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

For an endothermic reaction, where

ΔH

represent the enthalpy of reaction in

kJ {mol}^{- 1}

, the minimum value for energy of activation (for forward reaction) will be

EASY

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

The role of catalyst is to change

EASY

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

The enthalpy

(H)

of an elementary exothermic reaction

A ⇌ B

is schematically plotted against the reaction coordinate. The plots in the presence and absence of a catalyst are shown in dashed and solid lines, respectively. Identify the correct plot for the reaction.

EASY

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

In a chemical reaction, the effect of catalyst is to change

MEDIUM

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

For a reaction

A \to B,

enthalpy of reaction is

- 4.2 kJ {mol}^{- 1}

and enthalpy of activation is

9.6 kJ {mol}^{- 1} .

The correct potential energy profile for the reaction is shown in the option.

EASY

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

For an endothermic reaction

A \to B

, the possible potential energy versus progress of the reaction profiles are shown in the following options. The solid line represents potential energy in the absence of the catalyst, and dashed line represents potential energy in the presence of the catalyst. Which of the following options represents the CORRECT reaction profile?

MEDIUM

Chemistry>Physical Chemistry>Chemical Kinetics>Temperature Dependence of the Rate of a Reaction

According to the following figure, the magnitude of the enthalpy change of the reaction