CBSE
Multiple Choice QuestionsA first-order reaction has a specific reaction rate of 10–2 s–1. How much time will it take for 20 g of the reactant to reduce to 5 g?
238.6 second
138.6 second
346.5 second
346.5 second
The equilibrium constants of the following are.
The equilibrium constant (K) of the reaction:
A mixture of 2.3 g formic acid and 4.5 g oxalic acid is treated with conc. H2SO4. The evolved gaseous mixture is passed through KOH pellets. Weight (in gram) of the remaining product at STP will be
1.4
3.0
4.4
2.8
The correct difference between first and second order reactions is that
The rate of a first-order reaction does not depend on reactant concentrations; the rate of a second-order reaction does depend on reactant concentrations
The half-life of a first-order reaction does not depend on [A]0; the half-life of a second-order reaction does depend on [A]0
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
A first-order reaction can catalyzed; a second-order reaction cannot be catalyzed
When initial concentration of the reactant is doubled, the half-life period of a zero order reaction
Is halved
Is doubled
Remains unchanged
Is tripled
For the chemical reaction,
2O3 ⇌ 3O2
The reaction proceeds as follows
O3 ⇌ O2 + O
O + O3 → 2O2 (slow)
The rate law expression will be
r = k' [O3]2
r = k' [O3]2[O2]-1
r = k'[O3][O2]
unpredictable
In the following graph
The slope of line AB give the information of the
value of
Value of
value of
value of
A first-order reaction is 50% completed in 1.26 x 1014s. How much time would it take for 100% completion?
1.26 x 1015 s
2.52 x 1014 s
2.52 x 1028 s
Infinite
For the chemical reaction, 2O3 ⇌ 3O2. The reaction proceeds as follows
O3 ⇌ O2 + O (fast)
O + O3 → 2O2 (slow)
The rate law expression will be
r = k'[O3]2
r = k'[O3]2[O2]-1
r = k'[O3][O2]
Unpredictable
Two similar reactions have the same rate constant at 25C, but at 35C, one of the reaction has a higher rate constant than the other. The appropriate reason for this is
due to effective collisions
due to different activation energies
due to different threshold energies
due to higher population of molecules
