Question
A first order reaction takes 16 minutes for it's 50\% completion. What fraction that would react in 32 minutes from the beginning?
MHT CET
Chemistry
Chemical Kinetics
2026
MHT CET 2026 (13 April Shift 2)
MHT CET Chemistry Question (2026) — Solution
Options
- A. 1/2
- B. 1/4
- C. 1/8
- D. 3/4
Answer
D. 3/4
Step-by-step solution
For a first order reaction, the half-life is given as t_ 1/2 = 16 minutes. The time given is t = 32 minutes. The number of half-lives is n = t t_ 1/2 = 32 16 = 2. The fraction of the reactant remaining after n half-lives is 1 2^n . Fraction remaining = 1 2^2 = 1 4 . The fraction of the reactant that has reacted is 1 - 1 4 = 3 4 . Answer: 3/4
Related: Chemistry — Chemical Kinetics · All PYQ Banks