The correct statement among the following is:
1. | the rate of a first-order reaction does not depend on reactant concentration; the rate of a second-order reaction does depend on reactant concentrations. |
2. | the half-life of a first-order reaction does not depend on [A]o; the half-life of a second-order reaction does depend on [A]0 |
3. | a first-order reaction can be catalyzed; a second-order reaction cannot be catalyzed. |
4. | the rate of a first-order reaction does depend on reactant concentrations; the rate of a second-order reaction does not depend on reactant concentrations |
When the initial concentration of the reactant is doubled,
the half-life period of a zero-order reaction:
1. | is halved | 2. | is doubled |
3. | is tripled | 4. | remains unchanged |
Mechanism of a hypothetical reaction
is given below
(i)
(ii)
(iii)
The overall order of the reaction will be
1. 1
2. 2
3. 0
4. 1.5
A first order reaction has a specific reaction rate of 10-2s-1. How much time will it take for 20 g of the reactant to reduce to 5 g?
(a) 238.6 s (b) 138.6 s (c) 346.5 s (d) 693.0 s
The mechanism of a hypothetical reaction
X2 + Y2 → 2XY is given below:
(i) X2 → X + X (Fast)
(ii) X + Y2 ⇄ XY + Y (slow)
(iii) X + Y → XY (Fast)
The overall order of the reaction will be:
1. 2
2. 0
3. 1.5
4. 1
The incorrect statement among the following is:
1. | The value of the equilibrium constant is changed in the presence of a catalyst in the reaction at equilibrium |
2. | Enzymes catalyse mainly bio-chemical reactions |
3. | Coenzymes increase the catalytic activity of the enzyme |
4. | The catalyst does not initiate any reaction |
The decomposition of phosphine (PH3) on tungsten at low pressure is a first-order reaction. It is because the
(1) rate is proportional to the surface coverage
(2) rate is inversely proportional to the surface coverage
(3) rate is independent of the surface coverage
(4) rate of decomposition is very slow
The rate of a first-order reaction is 0.04 mol L-1 s-1 at 10 sec and 0.03 mol L-1 s-1 at 20 sec after initiation of the reaction. The half-life period of the reaction is
1. 34.1 s
2. 44.1 s
3. 54.1 s
4. 24.7 s
1. | Internal energy | 2. | Enthalpy |
3. | Activation energy | 4. | Entropy |