Q. Half life period of a first-order reaction is 1386 seconds. The specific rate constant of the reaction is:
A) 0.5 × 10⁻² s⁻¹
B) 0.5 × 10⁻³ s⁻¹
C) 5.0 × 10⁻² s⁻¹
D) 5.0 × 10⁻³ s⁻¹
Explanation
[Solution from source] For a first-order reaction k = 0.693/t½ = 0.693/1386 = 5.0 × 10⁻⁴ s⁻¹ = 0.5 × 10⁻³ s⁻¹. 5.0 × 10⁻³ s⁻¹ is ten times too large. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.