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
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 + 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 |
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.
The rate constant for a chemical reaction that takes place at 500 K is expressed as K = A e-1000. The activation energy of the reaction will be:
1. 100 cal/mol
2. 1000 kcal/mol
3. 104 kcal/mol
4. 106 kcal/mol
For the reaction,
N2O5(g) → 2NO2(g) + \(\frac{1}{2}\)O2(g)
the value of the rate of disappearance of is given as . The rate of formation of is given respectively as:
1. 6.25 x 10-3 mol L-1s-1 and 6.25 x 10-3 mol L-1s-1
2. 1.25 x 10-2 mol L-1s-1 and 3.125 x 10-3 mol L-1s-1
3. 6.25 x 10-3 mol L-1s-1 and 3.125 x 10-3 mol L-1s-1
4. 1.25 x 10-2 mol L-1s-1 and 6.25 x 10-3 mol L-1s-1
When the temperature of a reaction increases from 27 oC to 37 oC, the rate increases by 2.5 times. The activation energy in the temperature range will be:
1. 53.6 kJ
2. 12.61 kJ
3. 7.08 kJ
4. 70.8 kJ
The graph that represents a first-order reaction is:
1. | 2. | ||
3. | 4. |
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 |