In some cases it is found that a large number of colliding molecules have energy more than threshold energy but yet the reaction is slow.  Why?

2

(a)

The rate constant for a reaction of zero order in A is 0.0030 mol L^-1 s^-1.  How long will it take for the initial concentration of A to fall from 0.10 M to 0.075 M?

2

(a)

A reaction is second order with respect to a reactant. How is the rate of reaction affected if the concentration of the reactant is
(i) doubled?
(ii) reduced to half?

2

(a)

At 300 K a certain reaction is 50% completed in 20 minutes. At 350 K, the same reaction is 50% completed in 5 minutes. Calculate the activation energy for the reaction.

2

(a)

Derive an expression to calculate time required for completion of zero reaction.

2

(a)

Notric oxide, NO, reacts with Oxygen to produce nitrogen dioxide : 2NO (g) + O₂(g) \(\longrightarrow\) 2NO₂(g). The rate law for this, reaction is : Rate = k [NO]² [O₂].

2

(a)

Discuss any four factors which affect the rate of a chemical reaction.

2

(a)

Explain the term order of reaction. Derive the unit for first order rate constant.

2

(a)

How does a change in temperature affect the rate of a reaction? How can this effect on the rate constant of a reaction be represented quantitatively?

2

(a)

A systematic plot of ln Keq versus 1/T for a reaction has been shown below: Prove that this reaction is exothermic

2

(a)

In the reversible reaction.
Find out the rate of disappearance of NO₂

2

(a)

Why molecularity is applicable only for elementary reactions and order is applicable for elementary as well as complex reactions?

2

(a)