Question
The rate of reaction A + B P is 4 10^ -2 \ mol dm ^ -3 \ s ^ -1 When [A] = 0.2\ mole dm ^ -3 and [B] = 0.1\ mole dm ^ -3 , What is the rate constant of reaction, if it is first order with respect to A and second order with respect to B ?
MHT CET
Chemistry
Chemical Kinetics
2026
MHT CET 2026 (15 April Shift 2)
MHT CET Chemistry Question (2026) — Solution
Options
- A. 10\ mol ^ -2 dm ^6\ s ^ -1
- B. 20\ mol ^ -2 dm ^6\ s ^ -1
- C. 25\ mol ^ -2 dm ^6\ s ^ -1
- D. 40\ mol ^ -2 dm ^6\ s ^ -1
Answer
B. 20\ mol ^ -2 dm ^6\ s ^ -1
Step-by-step solution
The rate law for the given reaction is: Rate = k[A]^1[B]^2 Substituting the given values into the rate law equation: 4 10^ -2 = k(0.2)(0.1)^2 4 10^ -2 = k(0.2)(0.01) 4 10^ -2 = k(2 10^ -3 ) k = 4 10^ -2 2 10^ -3 k = 20\ mol ^ -2 dm ^6\ s ^ -1 Answer: 20\ mol ^ -2 dm ^6\ s ^ -1
Related: Chemistry — Chemical Kinetics · All PYQ Banks