Question
In a first order reaction, the concentration of the reactant, decreases from 0.8 M to 0.4 M in 15 minutes. The time taken for the concentration to change from 0.1 M to 0.025 M is
BITSAT
Chemistry
Chemical Kinetics
2024
BITSAT 2024 (Memory Based Paper 1)
BITSAT Chemistry Question (2024) — Solution
Options
- A. 7.5 minutes
- B. 15 minutes
- C. 30 minutes
- D. 60 minutes
Answer
C. 30 minutes
Step-by-step solution
As the concentration of reactant decreases from 0.8 to 0.4 in 15 minutes, hence the t_ 1 / 2 is 15 minutes. To fall the concentration from 0.1 to 0.025 , we need two half lives, i.e., 30 minutes.
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