For A + B C + D, H = -20 kJ mol-1 , the activation energy of the forward reaction is 85 kJ mol-1. The activation energy for the backward reaction is…. kJ mol-1.
1. | 105 | 2. | 85 |
3. | 40 | 4. | 65 |
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
A reaction A2 + B2 2AB occurs by the following mechanism:
A2 A + A .....(slow)
A + B2 AB + B .....(fast)
A + B AB .....(fast)
Its order would be:
1. 3/2
2. 1
3. 0
4. 2
For a given reaction, the presence of a catalyst reduces the energy of activation by 2 kcal at 27 oC. The rate of reaction will be increased by:
1. 20 times
2. 14 times
3. 28 times
4. 2 times
The following mechanism has been proposed for the reaction of NO with Br2 to form NOBr:
NO(g) + Br2(g) NOBr2(g)
NOBr2(g) + NO(g) 2NOBr(g)
If the second step is the rate determining step, the order of the reaction with respect to NO(g) will be:
1. 1
2. 0
3. 3
4. 2
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 first-order reaction A Products, the rate of reaction at [A] = 0.2 M is 1.0 x 10-2 mol litre-1 min-1. The half-life period for the reaction will be:
1. | 832 sec | 2. | 440 sec |
3. | 416 sec | 4. | 14 sec |
In the Arrhenius equation K = Ae-Ea/RT, the quantity e-Ea/kT is referred as:
1. Boltzmann factor.
2. Frequency factor.
3. Activation factor.
4. None of the above.
In the following reaction: xA → yB
where the -ve sign indicates the rate of disappearance of the reactant. Then, x : y equals:
1. | 1:2 | 2. | 2:1 |
3. | 3:1 | 4. | 3:10 |
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