If 'a' is the initial concentration of a substance that reacts according to zero-order kinetics and k is the rate constant, then the time for the reaction to go to completion is:
1. a/k
2. 2/ka
3. k/a
4. 2k/a
In a reaction, the rate expression is, rate = K[A][B]2/3[C]0, the order of the reaction is:
1. 1
2. 2
3. 5/3
4. zero
The rate of a reaction get doubles when the temperature changes from 7°C to 17°C. By what factor will it change for the temperature change from 17°C to 27°C?
1. 1.81
2. 1.71
3. 1.91
4. 1.76
For the elementary step, (CH3)3.CBr(aq) → (CH3)3C+ (aq) + Br- (aq), the molecularity is:
1. Zero
2. 1
3. 2
4. Cannot be ascertained
When ethyl acetate was hydrolysed in pressure of 0.1 N HCl, the rate constant was found to be 5.40 x 10-5 sec-1 . But when 0.1 N H2SO4 was used for hydrolysis, the rate constant was found to be 6.25 X10-5sec-1. Thus, it may be concluded that:
1. H2SO4 is stronger than HCI
2. H2SO4 is weaker than HCl
3. H2SO4 and HCl both have the same strength
4. The data are not sufficient to compare the strength of H2SO4 and HCI
The half time of a second order reaction is:
1. Inversely proportional to the square of the initial concentration of the reactants.
2. Inversely proportional to the initial concentration of the reactants.
3. Proportional to the initial concentration of reactants.
4. Independent of the initial concentration of reactants.
The half-life period of a first order chemical reaction is 6.93 minutes. The time required for the completion of 99% of the chemical reaction will be (log 2 = 0.301):
1. 23.03 minutes
2. 46.06 minutes
3. 460.6 minutes
4. 230.3 minutes
A zero order reaction is one:
1. in which reactants do not react
2. in which one of the reactants is in large excess
3. whose rate does not change with time
4. whose rate increases with time
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