Chemical Kinetics Practice Questions - DPP for JEE

 Page 1


PART-I (Single Correct MCQs)
1. The rate constant of the reaction A ? B is 0.6 × 10
–3
 mol L
–1
S
–1
. If the
concentration of A is 5 M then concentration of B after 20 minutes is :
(a) 1.08 M
(b) 3.60 M
(c) 0.36 M
(d) 0.72 M
2. In a reaction A ? Products, when start is made from8.0 × 10
–2
 M of A,
half-life is found to be 120 minute. For the initial concentration 4.0 ×
10
–2
 M, the half-life of the reaction becomes 240 minute. The order of
the reaction is :
(a) zero
(b) one
(c) two
(d) 0.5
Page 2


PART-I (Single Correct MCQs)
1. The rate constant of the reaction A ? B is 0.6 × 10
–3
 mol L
–1
S
–1
. If the
concentration of A is 5 M then concentration of B after 20 minutes is :
(a) 1.08 M
(b) 3.60 M
(c) 0.36 M
(d) 0.72 M
2. In a reaction A ? Products, when start is made from8.0 × 10
–2
 M of A,
half-life is found to be 120 minute. For the initial concentration 4.0 ×
10
–2
 M, the half-life of the reaction becomes 240 minute. The order of
the reaction is :
(a) zero
(b) one
(c) two
(d) 0.5
Exp. [A] [B] Initial rate
1 0.012 0.035 0.1
2 0.024 0.070 0.8
3 0.024 0.035 0.1
4 0.012 0.070 0.8
3. In a first-order reaction A B, if k is rate constant and initial
concentration of the reactant A is 0.5 M, then the half-life
is
(a)
(b)
(c)
(d)
4. The reaction A(g) + 2B(g) ? C(g) + D(g) is an elementary process. In
an experiment involving this reaction, the initial partial pressures of A
and B are p
A
 = 0.60 atm and p
B
= 0.80 atm respectively. When p
C
= 0.20
atm, the rate of the reaction relative to the initial rate is
(a) 1/6
(b) 1/12
(c) 1/36
(d) 1/18
5. Select the rate law that corresponds to data shown for the following
reaction
A + B  products.
(a) rate = k [B]
3
(b) rate = k [B]
4
(c) rate = k [A] [B]
3
Page 3


PART-I (Single Correct MCQs)
1. The rate constant of the reaction A ? B is 0.6 × 10
–3
 mol L
–1
S
–1
. If the
concentration of A is 5 M then concentration of B after 20 minutes is :
(a) 1.08 M
(b) 3.60 M
(c) 0.36 M
(d) 0.72 M
2. In a reaction A ? Products, when start is made from8.0 × 10
–2
 M of A,
half-life is found to be 120 minute. For the initial concentration 4.0 ×
10
–2
 M, the half-life of the reaction becomes 240 minute. The order of
the reaction is :
(a) zero
(b) one
(c) two
(d) 0.5
Exp. [A] [B] Initial rate
1 0.012 0.035 0.1
2 0.024 0.070 0.8
3 0.024 0.035 0.1
4 0.012 0.070 0.8
3. In a first-order reaction A B, if k is rate constant and initial
concentration of the reactant A is 0.5 M, then the half-life
is
(a)
(b)
(c)
(d)
4. The reaction A(g) + 2B(g) ? C(g) + D(g) is an elementary process. In
an experiment involving this reaction, the initial partial pressures of A
and B are p
A
 = 0.60 atm and p
B
= 0.80 atm respectively. When p
C
= 0.20
atm, the rate of the reaction relative to the initial rate is
(a) 1/6
(b) 1/12
(c) 1/36
(d) 1/18
5. Select the rate law that corresponds to data shown for the following
reaction
A + B  products.
(a) rate = k [B]
3
(b) rate = k [B]
4
(c) rate = k [A] [B]
3
Initial rate, Ms
–1
[A]
0
, M [B]
0
, M [C]
0
, M
5.0 × 10
–3
0.010 0.005 0.010
(d) rate = k [A]
2
 [B]
2
6. A radioactive element gets spilled over the floor of a room. Its half-life
period is 30 days. If the initial velocity is ten times the permissible
value, after how many days will it be safe to enter the
room?
(a) 100 days
(b) 1000 days
(c) 300 days
(d) 10 days
13. Consider the reaction :
The rate equation for this reaction is
rate = k[Cl
2
] [H
2
S]
Which of these mechanisms is/are consistent with this rate
equation?
A.   (slow)
(fast)
B.
(a) B only
(b) Both A and B
(c) Neither A nor B
(d) A only
8. The initial rates of reaction
3A + 2B + C  Products, at different initial concentrations are given
below:
Page 4


PART-I (Single Correct MCQs)
1. The rate constant of the reaction A ? B is 0.6 × 10
–3
 mol L
–1
S
–1
. If the
concentration of A is 5 M then concentration of B after 20 minutes is :
(a) 1.08 M
(b) 3.60 M
(c) 0.36 M
(d) 0.72 M
2. In a reaction A ? Products, when start is made from8.0 × 10
–2
 M of A,
half-life is found to be 120 minute. For the initial concentration 4.0 ×
10
–2
 M, the half-life of the reaction becomes 240 minute. The order of
the reaction is :
(a) zero
(b) one
(c) two
(d) 0.5
Exp. [A] [B] Initial rate
1 0.012 0.035 0.1
2 0.024 0.070 0.8
3 0.024 0.035 0.1
4 0.012 0.070 0.8
3. In a first-order reaction A B, if k is rate constant and initial
concentration of the reactant A is 0.5 M, then the half-life
is
(a)
(b)
(c)
(d)
4. The reaction A(g) + 2B(g) ? C(g) + D(g) is an elementary process. In
an experiment involving this reaction, the initial partial pressures of A
and B are p
A
 = 0.60 atm and p
B
= 0.80 atm respectively. When p
C
= 0.20
atm, the rate of the reaction relative to the initial rate is
(a) 1/6
(b) 1/12
(c) 1/36
(d) 1/18
5. Select the rate law that corresponds to data shown for the following
reaction
A + B  products.
(a) rate = k [B]
3
(b) rate = k [B]
4
(c) rate = k [A] [B]
3
Initial rate, Ms
–1
[A]
0
, M [B]
0
, M [C]
0
, M
5.0 × 10
–3
0.010 0.005 0.010
(d) rate = k [A]
2
 [B]
2
6. A radioactive element gets spilled over the floor of a room. Its half-life
period is 30 days. If the initial velocity is ten times the permissible
value, after how many days will it be safe to enter the
room?
(a) 100 days
(b) 1000 days
(c) 300 days
(d) 10 days
13. Consider the reaction :
The rate equation for this reaction is
rate = k[Cl
2
] [H
2
S]
Which of these mechanisms is/are consistent with this rate
equation?
A.   (slow)
(fast)
B.
(a) B only
(b) Both A and B
(c) Neither A nor B
(d) A only
8. The initial rates of reaction
3A + 2B + C  Products, at different initial concentrations are given
below:
5.0 × 10
–3
0.010 0.005 0.015
1.0 × 10
–2
0.010 0.010 0.010
1.25 × 10
–3
0.005 0.005 0.010
The order with respect to the reactants, A, B and C are respectively
(a) 3, 2, 0
(b) 3, 2, 1
(c) 2, 2, 0
(d) 2, 1, 0
9. In a reversible reaction the energy of activation of the forward reaction
is 50 kcal. The energy of activation for the reverse reaction will be
(a) < 50 kcal
(b) either greater than or less than 50 kcal
(c) 50 kcal
(d) > 50 kcal
10. Half life period of a first-order reaction is 1386 seconds. The specific
rate constant of the reaction is:
(a) 0.5 × 10
–2
 s
–1
(b) 0.5 × 10
–3
 s
–1
(c) 5.0 × 10
–2
 s
–1
(d) 5.0 × 10
–3
 s
–1
11. can be taken as the time taken for the concentration of a reactant to
drop to  of its initial value. If the rate constant for a first order
reaction is k, the  can be written as
(a) 0.75/k
(b) 0.69/k
(c) 0.29/k
(d) 0.10/k
12. Consider a reaction aG + bH ? Products. When concentration of both
the reactants G and H is doubled, the rate increases by eight times.
Page 5


PART-I (Single Correct MCQs)
1. The rate constant of the reaction A ? B is 0.6 × 10
–3
 mol L
–1
S
–1
. If the
concentration of A is 5 M then concentration of B after 20 minutes is :
(a) 1.08 M
(b) 3.60 M
(c) 0.36 M
(d) 0.72 M
2. In a reaction A ? Products, when start is made from8.0 × 10
–2
 M of A,
half-life is found to be 120 minute. For the initial concentration 4.0 ×
10
–2
 M, the half-life of the reaction becomes 240 minute. The order of
the reaction is :
(a) zero
(b) one
(c) two
(d) 0.5
Exp. [A] [B] Initial rate
1 0.012 0.035 0.1
2 0.024 0.070 0.8
3 0.024 0.035 0.1
4 0.012 0.070 0.8
3. In a first-order reaction A B, if k is rate constant and initial
concentration of the reactant A is 0.5 M, then the half-life
is
(a)
(b)
(c)
(d)
4. The reaction A(g) + 2B(g) ? C(g) + D(g) is an elementary process. In
an experiment involving this reaction, the initial partial pressures of A
and B are p
A
 = 0.60 atm and p
B
= 0.80 atm respectively. When p
C
= 0.20
atm, the rate of the reaction relative to the initial rate is
(a) 1/6
(b) 1/12
(c) 1/36
(d) 1/18
5. Select the rate law that corresponds to data shown for the following
reaction
A + B  products.
(a) rate = k [B]
3
(b) rate = k [B]
4
(c) rate = k [A] [B]
3
Initial rate, Ms
–1
[A]
0
, M [B]
0
, M [C]
0
, M
5.0 × 10
–3
0.010 0.005 0.010
(d) rate = k [A]
2
 [B]
2
6. A radioactive element gets spilled over the floor of a room. Its half-life
period is 30 days. If the initial velocity is ten times the permissible
value, after how many days will it be safe to enter the
room?
(a) 100 days
(b) 1000 days
(c) 300 days
(d) 10 days
13. Consider the reaction :
The rate equation for this reaction is
rate = k[Cl
2
] [H
2
S]
Which of these mechanisms is/are consistent with this rate
equation?
A.   (slow)
(fast)
B.
(a) B only
(b) Both A and B
(c) Neither A nor B
(d) A only
8. The initial rates of reaction
3A + 2B + C  Products, at different initial concentrations are given
below:
5.0 × 10
–3
0.010 0.005 0.015
1.0 × 10
–2
0.010 0.010 0.010
1.25 × 10
–3
0.005 0.005 0.010
The order with respect to the reactants, A, B and C are respectively
(a) 3, 2, 0
(b) 3, 2, 1
(c) 2, 2, 0
(d) 2, 1, 0
9. In a reversible reaction the energy of activation of the forward reaction
is 50 kcal. The energy of activation for the reverse reaction will be
(a) < 50 kcal
(b) either greater than or less than 50 kcal
(c) 50 kcal
(d) > 50 kcal
10. Half life period of a first-order reaction is 1386 seconds. The specific
rate constant of the reaction is:
(a) 0.5 × 10
–2
 s
–1
(b) 0.5 × 10
–3
 s
–1
(c) 5.0 × 10
–2
 s
–1
(d) 5.0 × 10
–3
 s
–1
11. can be taken as the time taken for the concentration of a reactant to
drop to  of its initial value. If the rate constant for a first order
reaction is k, the  can be written as
(a) 0.75/k
(b) 0.69/k
(c) 0.29/k
(d) 0.10/k
12. Consider a reaction aG + bH ? Products. When concentration of both
the reactants G and H is doubled, the rate increases by eight times.
However, when concentration of G is doubled keeping the
concentration of H fixed, the rate is doubled. The overall order of the
reaction is
(a) 0
(b) 1
(c) 2
(d) 3
13. The rate law for a reaction between the substances A and B is given by
Rate = k [A]
n
  [B]
m
On doubling the concentration of A and halving the concentration of B, the
ratio of the new rate to the earlier rate of the reaction will be as
(a) (m + n)
(b) (n – m)
(c) 2
(n – m)
(d)
14. The rate constants k
1
 and k
2
 for two different reactions are10
16
 . e
–2000/T
and 10
15
 . e
–1000/T
, respectively. The temperature at which k
1
 = k
2
 is
:
(a) 1000 K
(b)
(c) 2000 K
(d)
15. The slope in Arrhenius plot, is equal to:
(a)
(b)
(c)