MHT CET202615 April 2026Evening ShiftChemistryChemical KineticsActual
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 ?
Options
- A10 mol ⁻² dm ^6 s ⁻¹
- B20 mol ⁻² dm ^6 s ⁻¹
- C25 mol ⁻² dm ^6 s ⁻¹
- D40 mol ⁻² dm ^6 s ⁻¹
Correct 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