1.The branch of chemistry, which deals with the study of reaction rates and their mechanisms, is called ______________.

Ans:Chemical Kinetics

2.What are the factors that affect the rate of reaction?

Ans: The factors affecting rate of reaction are as follows:

- Concentration
- Temperature
- Pressure
- Presence of Catalyst
- Surface Area
- Radiation

3.Define Rate of Reaction.

Ans: The rate of a reaction can be defined as the change in concentration of a reactant or product in unit time.

4.Define Rate Law.

Ans: The representation of rate of reaction in terms of concentration of the reactants is known as rate law. It is also called a rate equation or rate expression.

5.The rate constant for first order reaction is 60/s. How much time will it take to reduce the concentration of the reaction to 1/10 of its initial value.

Ans:

The first order reaction is :

So the formula will be :

6.The initial concentration of N_{2}O_{5} in the following first order reaction
N_{2}O_{5}(g) → 2NO_{2}(g) + 1/2O_{2}(g) was 1.24 × 10^{–2} mol L^{–1} at 318 K. The
concentration of N_{2}O_{5} after 60 minutes was 0.20 × 10^{–2} mol L^{–1}.
Calculate the rate constant of the reaction at 318 K.

Ans:
The formula is :

After substituting the values we get :

7.
(a) What is the order of reaction whose rate constant has the same unit as the rate of
reaction?

(b) Thermal decomposition of a compound is of first order. 50% decomposes in 120 minutes. How long will it take for 90% to decompose?

Ans:

a) Zero order reaction.

b) The half life reaction to decompose takes 120mins

The formula is