H₂ gas is absorbed on the metal surface like tungsten. This follows ________ order reaction:

1. Third 

2. Second 

3. Zero 

4. First 

The elementary step of the reaction, $2 \mathrm{Na}+\mathrm{Cl}_{2}=2 \mathrm{NaCl}$  is found to follow 3^rd order kinetics. Its molecularity is:

1. 1

2. 2

3. 3

4. 4

The time for the half-life period of a certain reaction A → Products is 1 hour. When the initial concentration of the reactant 'A' is 2.0 mol L^-1, the time taken for its concentration to come from 0.50 to 0.25 mol L^-1 ,if it is a zero-order reaction, is-

1. 1h

2. 4 h

3. 0.5 h

4. 0.25 h

Consider the reaction, 2A + B → Products.
When concentration of B alone was doubled, the half-life did not change. When the concentration of A alone was doubled, the rate increased by two times. The unit of rate constant for this reaction is:

1. L mol^–1 s^–1

2. no unit

3. mol L^–1s^–1

4. s^–1

For the non – stoichiometry reaction 2A + B → C + D, the following kinetic data were obtained in three separate experiments (all at 298 K).

The rate law for the formation of C is:

1. $\frac{\mathrm{dc}}{\mathrm{dt}}=\mathrm{k}\left[\mathrm{A}{]}^2\right[\mathrm{B}]$

2. $\frac{\mathrm{dc}}{\mathrm{dt}}=\mathrm{k}\left[\mathrm{A}\right][\mathrm{B}{]}^2$

3. $\frac{\mathrm{dc}}{\mathrm{dt}}=\mathrm{k}\left[\mathrm{A}\right]$

4. $\frac{\mathrm{dc}}{\mathrm{dt}}=\mathrm{k}\left[\mathrm{A}\right]\left[\mathrm{B}\right]$