The rate constant of a first-order reaction is\(4 \times 10^{-3} \mathrm{sec}^{-1}.\) At a reactant concentration of \(0.02~\mathrm{M},\) the rate of reaction would be:
| 1. | \(8 \times 10^{-5} \mathrm{M} ~\mathrm{sec}^{-1} \) | 2. | \(4 \times 10^{-3} \mathrm{M} ~\mathrm{sec}^{-1} \) |
| 3. | \(2 \times 10^{-1} \mathrm{M}~ \mathrm{sec}^{-1} \) | 4. | \(4 \times 10^{-1} \mathrm{M}~ \mathrm{sec}^{-1}\) |
For a reaction of the type 2A + B 2C, the rate of the reaction is given by . When the volume of the reaction vessel is reduced to th of the original volume, the rate of reaction changes by a factor of:
1. 0.25
2. 16
3. 64
4. 4
For the elementary reaction M N, the rate of disappearance of M increases by a factor of 8 upon doubling the concentration of M. The order of the reaction with respect to M will be:
1. 4
2. 3
3. 2
4. 1
The rate of a reaction increases 4-fold when concentration of reactant is increased 16 times.
If the rate of reaction is 4 × 10-6 mol L-1s-1 when concentration of the reactant is 4 × 10-4 mol L-1, the rate constant of the reaction will be :
1. 2 × 10-4 m1/2 L-1/2 s-1
2. 1 × 10-2 s-1
3. 4 × 10-4 mol-1/2 L-1/2 s-1
4. 25 mol-1L min-1
If ‘a’ is the initial concentration of a substance which reacts according to zero-order kinetics and k is the rate constant, the time for the reaction to go to completion will be:
| 1. | a/k | 2. | 2/ka |
| 3. | k/a | 4. | Infinite |
For a general reaction A → B, the plot of concentration of A vs time is given below:
The unit of the rate constant would be:
| 1. | \(\mathrm{mol}^{-1} \mathrm{~L}^{-1} \mathrm{~s}^{-1} \) | 2. | \(s^{-1} \) |
| 3. | \(\mathrm{mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1} \) | 4. | None of the above |
Half-life is independent of the concentration of a reactant. After 10 minutes, the volume of N2 gas is 10 L and after complete reaction, it is 50 L. Hence, the rate constant is:
1. log 5 min-1
2. log 1.25 min-1
3. log 2 min-1
4. log 4 min-1
A first-order reaction is 15 % completed in 20 minutes. The amount of time required to complete 60 % of the reaction is:
| 1. | 112.8 min | 2. | 120.7 min |
| 3. | 100.4 min | 4. | 140.7 min |
Consider the first-order gas-phase decomposition reaction given below.
A(g) → B(g) + C(g)
The initial pressure of the system before the decomposition of A was . After the lapse of time t, the total pressure of the system increased by X units and became . The rate constant k for the reaction is:
| 1. | 2. | ||
| 3. | 4. |