Unit VII: Chemical Kinetics - Online Test
Q1. What is the activation
energy for a reaction if its rate doubles when the temperature is raised from
200K to 400K? (R = 8.314 JK-1mol-1)
Answer : Option C
Explaination / Solution:
T1 = 200K ; k = k1
T2 = 400K ; k = k2
= 2k1
Q2. 
This reaction follows first
order kinetics. The rate constant at particular temperature is 2.303 × 10−2 hour−1 . The initial concentration of cyclopropane is 0.25M. What will be the concentration of cyclopropane after 1806 minutes?
(log 2 = 0.3010)
This reaction follows first
order kinetics. The rate constant at particular temperature is 2.303 × 10−2 hour−1 . The initial concentration of cyclopropane is 0.25M. What will be the concentration of cyclopropane after 1806 minutes?
(log 2 = 0.3010)
Answer : Option B
Explaination / Solution:
Q3. For a first order reaction,
the rate constant is 6.909 min-1.the time taken for 75% conversion
in minutes is
Answer : Option B
Explaination / Solution:
Q4. In a first order reaction x → y ; if k is the rate constant and the initial concentration of the reactant x
is 0.1M, then, the half life is
Answer : Option C
Explaination / Solution:
Q5. 
Predict the rate law of
the following reaction based on the
data given below
2A + B → C + 3D
Answer : Option B
Explaination / Solution:
Q6.
Assertion: rate of reaction doubles
when the concentration of the reactant is doubles if it is a first order
reaction.
Answer : Option C
Explaination / Solution:
For a first reaction, If
the concentration of reactant is doubled, then the rate of reaction also
doubled.
Rate constant is
independent of concentration and is a constant at a constant temperature,
Q7. The rate constant of a reaction
is 5.8 × 10−2
s−1 . The order of the reaction is
Answer : Option A
Explaination / Solution:
The unit of rate constant is s-1 and it indicates that the reaction is first order.
Q8. For the reaction N2O5(g) → 2NO2
(g) + ½ O2(g), the value of rate of disappearance of N2O5
is given as 6.5 × 10-2 mol L-1
s-1. The rate of formation of NO2 and O2 is
given respectively as
Answer : Option C
Explaination / Solution:
Q9. During the decomposition of
H2O2 to give dioxygen, 48 g O2 is formed per
minute at certain point of time. The rate of formation of water at this point
is
Answer : Option D
Explaination / Solution:
no of moles of oxygen = (48/32) =
1.5 mol
∴
rate of formation of oxygen = 2 ×1.5
= 3 mol min-1
Q10. If the initial concentration of the reactant is doubled, the time for half reaction is also doubled. Then the order of the reaction is
Answer : Option A
Explaination / Solution:
For a first order reaction
t1/2 is independent of initial concentration .i.e., ∴ n ≠ 1; for such cases
