Chemical Kinetics Practice Questions
NEET · Chemistry · 1594 free MCQs with instant results and detailed explanations.
1594
Total
342
Easy
702
Medium
550
Hard
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Topics in Chemical Kinetics
Order of Reaction
393
Rate Law
376
Integrated Rate Equations
396
Arrhenius Equation
429
Sample Questions from Chemical Kinetics
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What does the rate law expression depend on?
A.
Concentration of reactants
B.
Nature of products
C.
Temperature only
D.
Volume of reaction mixture
Show Answer & Explanation
Correct Answer: A
The rate law expression is formulated based on the concentrations of the reactants and their orders, making the concentration of reactants crucial.
Q2
Easy
If the rate law for a reaction is given by rate = k[A]^2[B], what is the overall order of the reaction?
A.
2
B.
3
C.
1
D.
0
Show Answer & Explanation
Correct Answer: B
The overall order of a reaction is the sum of the powers of the concentration terms in the rate law, which is 2 (from A) + 1 (from B) = 3.
Q3
Easy
In a zero-order reaction, how does the rate change with concentration of the reactant?
A.
Rate increases with concentration
B.
Rate decreases with concentration
C.
Rate is constant
D.
Rate is proportional to concentration squared
Show Answer & Explanation
Correct Answer: C
In zero-order reactions, the rate is independent of the concentration of the reactant, hence it remains constant.
Q4
Medium
For a first-order reaction, if the half-life is 30 minutes, what will be the time taken for 75% of the reactant to be converted into products?
A.
90 minutes
B.
60 minutes
C.
120 minutes
D.
45 minutes
Show Answer & Explanation
Correct Answer: A
For a first-order reaction, the relationship between half-life and the time to reach a certain conversion can be derived from the equation: t = n * t1/2, where n is the number of half-lives. To convert 75% of the reactant, 2 half-lives (30 min each) are required, which totals 90 minutes.
Q5
Medium
Which of the following correctly represents the rate law for the reaction: A + 2B → C, if the rate of reaction is found to depend on the concentration of A to the power of 1 and B to the power of 2?
A.
Rate = k[A]^1[B]^2
B.
Rate = k[A]^2[B]^1
C.
Rate = k[A]^2[B]^2
D.
Rate = k[A]^1[B]^1
Show Answer & Explanation
Correct Answer: A
The rate law is determined by the reaction order with respect to each reactant. The given dependencies indicate that the reaction rate is first-order in A and second-order in B, leading to the expression Rate = k[A]^1[B]^2.
Q6
Medium
If the rate constant (k) of a reaction doubles when the temperature is increased by 10°C, what can be inferred about the activation energy of the reaction?
A.
It is low
B.
It is high
C.
It is constant
D.
It can be zero
Show Answer & Explanation
Correct Answer: A
A doubling of the rate constant with a 10°C increase indicates a relatively low activation energy. According to the Arrhenius equation, a small increase in temperature leads to a significant increase in the rate constant when the activation energy is low.
Q7
Medium
In a zero-order reaction, if the initial concentration of the reactant is 0.5 M and the rate constant is 0.1 M/s, how long will it take for the concentration to reach 0?
A.
5 seconds
B.
2 seconds
C.
0.5 seconds
D.
4 seconds
Show Answer & Explanation
Correct Answer: A
For a zero-order reaction, the time to reach completion can be calculated using the formula: time = [A]0 / k. Here, time = 0.5 M / 0.1 M/s = 5 seconds.
Q8
Hard
For the reaction A + 2B → C, the initial rate is measured at different initial concentrations of A and B. If the initial rate is found to be proportional to [A]^2 and independent of [B], what is the overall order of the reaction?
A.
2
B.
3
C.
1
D.
0
Show Answer & Explanation
Correct Answer: A
Since the rate is proportional to [A]^2 and independent of [B], the overall order of the reaction is simply the sum of the exponents in the rate law, which in this case is 2.
Q9
Hard
A first-order reaction has a rate constant k of 0.693 min^-1. What will be the time taken for the concentration of the reactant to reduce to half its initial concentration?
A.
1 min
B.
2 min
C.
0.693 min
D.
3 min
Show Answer & Explanation
Correct Answer: A
For a first-order reaction, the half-life (t1/2) is given by t1/2 = 0.693/k. Substituting k = 0.693 min^-1 gives t1/2 = 1 min.
Q10
Hard
For the reaction A → B, the rate law is given by rate = k[A]². What is the order of the reaction?
A.
1
B.
2
C.
0
D.
3
Show Answer & Explanation
Correct Answer: B
The order of a reaction is determined by the exponent of the concentration term in the rate law. Here, the exponent of [A] is 2, indicating that it is a second-order reaction.
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Chemical Kinetics — NEET Chemistry Practice Questions Online
This page contains 1594 practice MCQs for the chapter Chemical Kinetics in NEET Chemistry. The questions are organized by difficulty — 342 easy, 702 medium, 550 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit. This chapter covers 4 topics, giving you comprehensive coverage of the entire chapter.