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CUET Chemistry Questions Chemical Kinetics

Hi CUET aspirants, Welcome to Amans Maths Blogs (AMBIPi). In this post, you will get CUET Chemistry Mock Test Chemical Kinetics AMBIPi. This CUET Chemistry Mock Test is of the Chemistry chapter Chemical Kinetics. Before solving these CUET Chemistry questions, you must read CUET Chemistry Notes, which helps you to revise CUET Chemistry Syllabus and then you must need to solve CUET Previous Years Questions Papers.

CUET Chemistry Mock Test

CUET Chemistry Question No: 1

Rate of which of the following reactions can be determined easily?

Option A : Rusting of iron in the presence of air and moisture

Option B : Hydrolysis of starch

Option C : Reaction of silver nitrate with sodium chloride

Option D : All of the above

Show/Hide Answer Key

Option B: Hydrolysis of starch

Rate of only those chemical reactions can be determined easily which occurs at moderate speed, e.g. hydrolysis of
starch, inversion of cane sugar etc.

CUET Exam Chemistry Question No: 2

For the reaction,

2 X + Y → X2 Y

What will be the expression for instantaneous rate of the reaction?

Option A : −d [X]/ 2dt

Option B : +1/2 d [Y]/dt

Option C : +1/2 d [Y]/dt

Option D : None of these

Show/Hide Answer Key

Option A: −d [X]/ 2dt 

For the reaction, 2 X + Y → X2

The instantaneous rate of the reaction is given as, 

– d [X]/ 2dt = -d[Y]/dt = + d[X2Y/dt

CUET UG Chemistry Question No: 3

Choose the correct value of d[ NH3] / dt for the reaction

N2 + 3 H2 → 2 NH3

Option A : -2/3 d[H2] / dt

Option B : 2/3 d [H2]

Option C : 3/2 d [N2]/ dt

Option D : -3/2 d [N2]/ dt

Show/Hide Answer Key

Option A: -2/3 d[H2] / dt

For the reaction, N2 + 3 H2 → 2 NH3 

The instantaneous rate of reaction is given as

d[N2]/ dt = -d [H2]/ 3dt = +d [ NH3]/ 2dt 

d [NH3]/dt = 2/3 d[H2]/ dt

CUET Domain Subject Chemistry Question No: 4

In a reaction, 2x → y, the concentration of x decreases from 3.0 M to 1.5 M in 4 min.

Option A : 0.187 M min −1

Option B : 1.87 M min −1

Option C : 3.75 10-1M min −1

Option D : 0.75 M min −1

Show/Hide Answer Key

Option A: 0.187 M min −1

Rate of reaction = – 1/2 d[x]/ dt = -1/2 [1.5 – 3.0]/ 4

= 1.5 /8 = 0.187 M min-1

CUET BSc Chemistry Question No: 5

Rate law cannot be determined from balanced chemical equation, if ……… .

Option A : reverse reaction is involved

Option B : it is an elementary reaction

Option C : it is a sequence of elementary reactions

Option D : Both (a) and (c)

Show/Hide Answer Key

Option B: it is an elementary reaction

CUET Entrance Exam Chemistry Question No: 6

On mixing 1 dm3 of 3M ethanol with 1 dm3 of 2 M ethanoic acid, an ester is formed

C2 H5 OH + CH3 COOH → CH3 COOC2H5 + H2O

If each solution is diluted with an equal volume of water, the decrease in the initial rate would be

Option A : 0.5 times

Option B : 3 times

Option C : 0.25 times

Option D : 2 times

Show/Hide Answer Key

Option C: 0.25 times

For the given reaction,

C2 H5 OH + CH3  COOH → CH3 COOC2 H5 + H20

r = k [CH3 COOH] [C2 H5 OH]

or r = k [n/v] [n/v] 

Increasing volume (V) by twice (due to dilution) will reduce the
rate by 4 times. 

r = 0.25 k [CH3 COOH[ [C2 H5 OH]

CUET Exam Question No: 7

Which of the following rate expression is correct against its reaction?

Option A : 2 NO (g) + O2 (g) + 2 NO2 (g) → 2 NO2 (g) ; Rate = k [NO]2  [O2]

Option B : CHCI3 + CI2  → CCI4 + HCI; Rate = k [ CH CI3] [CI2]1/2

Option C : CH3 COO C2 H5 + H20 → CH3 COOH + C2 H5 OH; Rate = k [CH3 COOC2 H5]1 [H2O]0

Option D : All of the above

Show/Hide Answer Key

Option D: All of the above

CUET Chemistry Practice Questions No: 8

Consider the following reactions,

O3 ⇔ O2 + 0 (fast)

O + O3 → 2 O2 (slow)

The rate law expression should be

Option A : r = k [O3]2 [O2]-1

Option B : r = k [O3] [O2]

Option C : r = k [O3]2

Option D : r = k [O2]-1

Show/Hide Answer Key

Option A: r = k [O3]2 [O2]-1

Given, O3 ⇔ O2 + O (fast)

O + O3 → 2 O2 (slow)

From Eq, (i) K eq= [O2] [O] / [O3]

or 

From Eq, (ii) rate law = k[O3] [O]

or

r = k [O3] [O3]/ [O2] Keq

or

r = k’ [O3]2 [O2]-1 [k’ = k x  k eq]

CUET Chemistry Sample Paper Question No: 9

Reaction of chloroform with chlorine is an example of fraction order reaction. Its rate law expression is rate = k[CHCl3 ][Cl 2] 1/ 2 . If both are assumed in gaseous state and pressure is measured in bar, then units of rate and rate constant respectively are

Option A : bar min-1, bar2 min-1

Option B : bar min-1, bar -1/2 , min-1

Option C : bar -1/2, min -1, bar2 , min-1

Option D : bar min-1 , bar -1/2 , min-1

Show/Hide Answer Key

Option D: bar min-1 , bar -1/2 , min-1

Given, rate = k [CH CI3] [CI2]1/2 

Order = 1+ 1/2 = 3/2  Units of rate constant = Units of rate / [CH CI3] [CI2]1/2

= bar min-1/ bar 3/2 = bar-1/2 min-1 and units of rate is bar min-1

CUET Chemistry Mock Test Question No: 10

The rate constant is numerically equal for three reactions of first, second and third order respectively.Which of the following is true?

Option A : If [A] > 1 ; r3 > r2 > r1

Option B : If [A]  = 1; r1 = r2 = r3

Option C : If [A] < 1; r1 > r2 > r3

Option D : All of the above

Show/Hide Answer Key

Option D: All of the above

CUET Chemistry Question No: 11

For the reaction, I + OCI → IO- + CI in aqueous medium, the rate of a reaction is given by

d[IO]/ dt = k [I] [OCI]/ [OH] the overall order of reaction is 

Option A : -1

Option B : 1

Option C : 0

Option D : 2

Show/Hide Answer Key

Option B: 1

The rate of reaction is given by, d [IO]/ dt = k [I] [OCI]/ [OH

Therefore, overall order of reaction = + − 1 1 1= 1

CUET Exam Chemistry Question No: 12

The reaction,

2 N2 O5 ⇔ 2N2 O4 + 02

Option A : bimolecular and first order

Option B : unimolecular and second order

Option C : bimolecular and second order

Option D : unimolecular and first order

Show/Hide Answer Key

Option A: 1.86A

The given reaction, 

i.e. 2 N2 O5 ⇔ 2 N2 04 + 0

occurs in two steps and, hence biomolecular reaction and the rate determining step is the slowest step which is of first order.

CUET UG Chemistry Question No: 13

Four reactions are given below. Which one of them is of zero order?

Option A : PCI5 → PCI3 + CI2

Option B : 2 FeCI3 + SNCI2 → 2 Fe CI2 + Sn CI4

Option C : H2 + CI2 → 2 HCI

Option D : N2 O5 → 2 NO2 + 1/2 O2

Show/Hide Answer Key

Option C: H2 + CI2 → 2 HCI

Among the given reactions, reaction between hydrogen and chlorine under influence of UV-light is an example of zero
order reaction, 

i.e  H2 + CI2 → 2 HCI

CUET Domain Subject Chemistry Question No: 14

Higher order (>3) reactions are rare due to

Option A : low probability of simultaneous collision of all the reacting species

Option B : increase in entropy and activation energy as more molecules are involved

Option C : shifting of equilibrium towards reactants due to elastic collisions

Option D : loss of active species on collision

Show/Hide Answer Key

Option A: low probability of simultaneous collision of all the reacting species

CUET BSc Chemistry Question No: 15

For a zero order reaction, a graph of concentration (along y-axis) and time (along x-axis) is linear with

Option A : a zero intercept and a +ve slope

Option B : a zero intercept and a –ve slope

Option C : a non-zero intercept and a –ve slope

Option D : a non-zero intercept and a +ve slope

Show/Hide Answer Key

Option B: a non-zero intercept and a –ve slope

For a zero order reaction, a graph of concentration and time is linear with a non-zero intercept,[R]0 and a (-)ve slope, -k

CUET Entrance Exam Chemistry Question No: 16

The rate constant of the reaction, A B → is 06 10 -3. ×−mole per litre per second. If the concentration of A is 5 M then, concentration of B after 20 min is

Option A : 1.08 M

Option B : 3.60 M

Option C : 0.36 M

Option D : 0.72 M

Show/Hide Answer Key

Option D: 0.72 M

For a zero order reaction, unit of rate constant is (mol L-1 s-1).
Hence, we can easily calculate the concentration of B after 20 min by the following formula, X = kt = 0.6 x 10-3 x 20  x 60 = 0.72 M

CUET Exam Question No: 17

A first order has a rate constant of 2.303 x 10-3 s-1. The time required for 40 g of this reactant to reduce to 10 g will be

[Given that log10 2 = 0.3010]

Option A : 230.3 s

Option B : 301 s

Option C : 2000 s

Option D : V∞ – V0 / V∞ – Vt

Show/Hide Answer Key

Option D: V∞ – V0 / V∞ – Vt

For first order reaction, t = 2.303/ k log a/a-x 

Given k = 2.303 x 10-3 s-1 a = 40g , a-x= 10g,

On substituting the given values in Eq. (i), we get

t = 2.303/ 2.303 x 10-3 log 40/10 = 103 log 22 = 2 x 103 x log2 = 2 = 103 x 0.3010 = 602 s 

Alternative method 

For first order reaction,  t1/2 = 0.693/k ⇒ t1/2 (t50%) = 0.693/ 2.303  x 10-3 = 301s  Also, t75% = 2t50%

t75% = 2x 301 = 602 s

CUET Chemistry Practice Questions No: 18

For a first order reaction,

Option A : t 1/2 = k/a

Option B : t 3/4 = 2t 1/2

Option C : t 1/2 = 0.693/ 2k

Option D : t 1/2 = k x 0.693

Show/Hide Answer Key

Option B: t 3/4 = 2t 1/2

Decomposition of benzene diazonium chloride occur the following manner.  C6 H5 N+ ≣ NCI → C6 H5 CI + N2 ↑ 

The volume of nitrogen obtained shows the extent of decomposition of benzene diazonium chloride, so

a ∝ V∞ = 162 mL 

(a-x) ∝ (V∞ – Vt) mL 

For first order reaction, k = 2.303/t log10 V∞ – V0 / V∞ – Vt or

k = 2.303/ t log10  V∞ – V0 / V∞ – Vt

At 20 min,

k = 2.303/20 log10 162/ 162-10 = 2.303/20 log10  162/152

= 3.18 x 10-3 min-1 = 3.2 x10-3 min-1

CUET Chemistry Sample Paper Question No: 19

If half-life of a substance is 36 minutes. The amount left after 2 hrs will be [Given (A0) = 10 g)

Option A : 1 g

Option B : 2 g

Option C : 3 g

Option D : 4 g

Show/Hide Answer Key

Option A: 1 g

Given, t 1/2 = 36 min , t = 2 hours = 120 min, [A]0 = 10 g

For first order reaction,

k = 0.693/ t1/2 

k = 0.693/36 = 0.01925

As, we know that, t = 2.303/ k log [A]0/ [A] 

where [A]0 = initial amount [A] = final amount

120 = 2.303/ 0.019 log [A]0 / [A] log 10 – log [A] = 1 ⇒ 1 – log [A] =1

Thus, [A] = 1 g

CUET Chemistry Mock Test Question No: 20

99% completion of a first order reaction takes place in 32 min. The time taken in 99.9% completion of the reaction will be

Option A : 48 min

Option B : 52 min

Option C : 56 min

Option D :44 min 

Show/Hide Answer Key

Option A: 48 min

For first order reaction, k = 2 303/ t log a / a-x   

k =  2.303/ 32 min log a/ a- 0.99a = 0.1439 min -1

⇒ t = 2.303/ 0.1439 log  a / a- 0.999 a = 48 min

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