MHT CET202620 April 2026Evening ShiftChemistryChemical KineticsActual
Calculate the rate constant of first order reaction A B having rate 5.4 10⁻⁶ mol dm ⁻³ s ⁻¹ and [ A ] = 0.3 M.
Options
- A1.52 10⁻⁵ s ⁻¹
- B1.68 10⁻⁵ s ⁻¹
- C1.72 10⁻⁵ s ⁻¹
- D1.80 10⁻⁵ s ⁻¹
Correct answer
D. 1.80 10⁻⁵ s ⁻¹
Step-by-step solution
For a first order reaction, the rate law is given by: Rate = k[ A ] Substituting the given values: 5.4 10⁻⁶ = k 0.3 k = 5.4 10⁻⁶ 0.3 k = 18 10⁻⁶ s ⁻¹ k = 1.80 10⁻⁵ s ⁻¹ Answer: 1.80 10⁻⁵ s ⁻¹