Collision Theory and Activation Energy

State the postulates of collision theory. Explain the effect of temperature, concentration and catalyst on the rate of reaction.

An increase in pressure increases the rate of reaction due to the increase in the number of collisions amongst the molecules.

Threshold energy$=$Energy of normal molecules $+$ Activation energy.

Though the kinetic energy of electrons decreases with an increase in the distance from the nucleus, the potential energy of the electron increases. How do you account for this?

Explain the effect of a catalyst on the rate of reaction on the basis of collision theory.

How do you explain the effect of concentration on the rate of reaction on the basis of collision theory? 

What are effective collisions?

From the following data ${\mathrm{H}}_{2 }+ {\mathrm{I}}_2 \to 2\mathrm{HI}$

Which of the following is the appropriate ${\mathrm{E}}_{\mathrm{a}}$ of the reaction?

The rate constant for the reaction: ${\mathrm{CH}}_3\mathrm{CHO}\left(\mathrm{g}\right) \to {\mathrm{CH}}_4\left(\mathrm{g}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)$ are $0.035 {\mathrm{M}}^2{\mathrm{S}}^{-1} \mathrm{at} 730\mathrm{K} \mathrm{and} 0.343 {\mathrm{M}}^2 \mathrm{at} 790\mathrm{K}$

Calculate activation energy of the reaction.($\mathrm{R}=8.314{\mathrm{Jk}}^{-1}{\mathrm{mol}}^{-1}$)

The rate constants of a reaction at $400 \mathrm{K} \mathrm{and} 600 \mathrm{K}$ are $5 \mathrm{x} {10}^{-3} \mathrm{s}{ }^{–1} \mathrm{and} 8 \mathrm{x} {10}^{-3} \mathrm{s}{ }^{–1}$ respectively. What extra piece of information is needed to calculate the value of $\mathrm{A}$ (frequency factor)?

(According to the Arrhenius equation, rate constant is given by, $\mathrm{k} = {\mathrm{Ae}}^{-\mathrm{E}{ }_{\mathrm{a} }/\mathrm{RT}}.$)

Why do colliding molecules have activation energy?

Write a short note on 'collision theory of reaction rates'.

What is activation energy ? How is the rate constant of a reaction related to its activation energy?

Define energy of activation. Draw diagram of energy profile to show the influence of a positive catalyst on the energy of activation of a reaction.

Define the term activation energy. Why different reactions proceed at different speeds?

What are the two necessary conditions for a collision between two molecules to be effective collision?

Define activation energy of a reaction.

Given that the enthalpy change of a reaction at $325 \mathrm{K}$ is $0.12 \mathrm{kcal}$ and energy of activation for the backward reaction is $0.02$ kcal, calculate the percentage of the reactant molecules, crossing over the energy barrier.