Chemical Kinetics NEET PYQs (1994–2026)

Solved Chemical Kinetics PYQs

3 recent questions with answers. The full set of 80 is free to practise.

1. NEET 2026MediumIntegrated Rate Laws
   Q1

   $2A\stackrel{k}{\to }B$ is a zero-order reaction, where $k=1.0{\text{ mol L}}^{-1}{\text{ min}}^{-1}$. If the initial concentration of $A$ is $2\text{ M}$, then the time taken to complete $75\%$ of the reaction will be:

   • A1.5 min
   • B0.75 min
   • C1.0 min
   • D2.0 min

   Show answer & solution

   Correct answer: (B)

   For zero order reaction: $[A]=[A{]}_0-kt$.
   
   $75\%$ completion means $[A]=0.25\times 2=0.5$ M.
   
   $$0.5=2-1.0\times t$$
   
   $\Rightarrow t=1.5$ min.
   
   the reaction is $2A\to B$, so rate =
   
   $$-\frac{1}{2}\frac{d[A]}{dt}=k$$
   
   $\Rightarrow -\frac{d[A]}{dt}=2k$.
   
   So $[A]=[A{]}_0-2kt$.
   
   $$0.5=2-2\times 1.0\times t$$
   
   $\Rightarrow t=0.75$ min.
2. NEET 2026MediumArrhenius Equation
   Q2

   Given below is an expression for the rate constant of a first-order reaction occurring at a certain temperature, T (K).
   
   $$\ln k=14.34-\frac{1.25\times 10^4}{T}$$
   
   The energy of activation in kcal mol^-1 for the reaction is:
   
   (Given: k in s^-1, R = 1.987 cal mol^-1 K^-1)

   • A24.84
   • B14.34
   • C18.63
   • D12.42

   Show answer & solution

   Correct answer: (A)

   From Arrhenius: $\ln k=lnA-\frac{E_a}{RT}$. So
   
   $E_a/R=1.25\times 10^4$.
   
   $E_a=1.25\times 10^4\times 1.987=24837.5$ cal = 24.84 kcal.
3. NEET 2026MediumOrder and Molecularity
   Q3

   Match List I with List II:
   
   List-I (Order of reaction):
   
   A. Zero order,
   
   B. First order,
   
   C. Second order,
   
   D. Third order
   
   List-II (Unit of rate constant):
   
   I. mol^-1 L s^-1,
   
   II. mol^-² L² s^-1,
   
   III. s^-1,
   
   IV. mol L^-1 s^-1
   
   Choose the correct answer from the options given below:

   • AA-IV, B-II, C-I, D-III
   • BA-IV, B-III, C-I, D-II
   • CA-IV, B-III, C-II, D-I
   • DA-I, B-II, C-III, D-IV

   Show answer & solution

   Correct answer: (B)

   Zero order: mol L^-1 s^-1 (IV); First: s^-1 (III); Second: mol^-1 L s^-1 (I);
   
   Third: mol^-² L² s^-1 (II). So A-IV, B-III, C-I, D-II.

Topic-wise question count

Where NEET has asked from Chemical Kinetics, most frequent first.

• Order and Molecularity17
• Activation Energy14
• Integrated Rate Laws11
• Reaction Mechanisms11
• Rate of Reaction9
• Arrhenius Equation7
• Half-Life7
• Factors Affecting Rate3
• half-life1

Year-wise Chemical Kinetics questions in NEET

Number of questions from this chapter in each year's paper(s).