The half-life for a zero-order reaction having 0.02 M initial concentration of reactant is 100 s. The rate constant (in mol L^-1 s^-1) for the reaction is:

1. $1.0\times {10}^{-4}$

2. $2.0\times {10}^{-4}$

3. $2.0\times {10}^{-3}$

4. $1.0\times {10}^{-2}$

The unit of rate constant for a zero-order reaction is:

1. ${\mathrm{s}}^{-1}$

2. $\mathrm{mol}$ ${\mathrm{L}}^{-1}{\mathrm{s}}^{-1}$

3. $\mathrm{L}$ ${\mathrm{mol}}^{-1}{\mathrm{s}}^{-1}$

4. ${\mathrm{L}}^2{\mathrm{mol}}^{-2}{\mathrm{s}}^{-1}$

The half-life of a certain enzyme catalysed reaction is 138 s, that follow the 1st order kinetics. The time required for the concentration of the substance to fall from 1.28 mg L^–1 to 0.04 mg L^–1, is:

1. 276 s 

2. 414 s

3. 552 s 

4. 690 s

The rate of the reaction $2{\mathrm{N}}_2{\mathrm{O}}_5\to 4{\mathrm{NO}}_2+{\mathrm{O}}_2$  can be written in three ways:

$\frac{-d\left[N_2{O}_5\right]}{dt}=k\left[N_2{O}_5\right]$
$\frac{d\left[N{O}_2\right]}{dt}=k\text{'}\left[N_2{O}_5\right]$
$\frac{d\left[O_2\right]}{dt}=k\text{'}\text{'}\left[N_2{O}_5\right]$

The relationship between k and k′ and between
k and k′′ are-

1. k′ = k, k′′= k 

2. k′= 2k; k′′= k

3. k′= 2k, k′′= k/2 

4. k′ = 2k; k′′= 2k

The rate of the reaction

2NO + Cl₂ → 2NOCl is given by the rate equation
rate = k[NO]²[Cl₂]

The value of the rate constant can be increased by: 

1. Increasing the concentration of NO
2. Increasing the concentration of Cl₂
3. Increasing the temperature
4. All of the above

A 300-gram radioactive sample has a half-life of 3 hours. After 18 hours the remaining quantity will be:

1. 4.68 gram

2. 2.34 gram

3. 3.34 gram

4. 9.37 gram

The rate of reaction between two reactants A and B decreases by a factor of 4 if the concentration of reactant B is doubled. The order of this reaction with respect to reactant B is:

1. 2

2. –1

3. 1

4. –2

For a first-order reaction A → B the reaction rate at a reactant concentration of 0.01M is found to be $2.0\times {10}^{-5}\text{ mole }{\mathrm{L}}^{-1}{\mathrm{s}}^{-1}$. The half-life period of the reaction is:
1. 300s
2. 30s
3. 220s
4. 347s

If the concentration of a solution is changed from 0.2 to 0.4, then what will be rate and rate constant. The reaction is of first order and rate constant is $K=1\times {10}^{-6}$: 

1. $2\times {10}^{-7}$ $;$ $1\times {10}^{-6}$

2. $1\times {10}^{-7}$ $;$ $1\times {10}^6$

3. $4\times {10}^{-7}$ $;$ $1\times {10}^{-6}$

4. $2\times {10}^{-3}$ $;$ $1\times {10}^{-3}$

Half-life of a radioactive sample is 4 days. After 16 days what quantity of matter remains undecayed?

1. $\frac{1}{4}$

2. $\frac{1}{8}$

3. $\frac{1}{16}$

4. $\frac{1}{32}$