Chemical Kinetics Question 201
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 [AIEEE 2004]
Options:
A) 7.5 minutes
B) 15 minutes
C) 30 minutes
D) 60 minutes
Show Answer
Answer:
Correct Answer: C
Solution:
The concentration of the reactants decrease from 0.8 to 0.4 in 15 min i.e., $ {T_{1/2}}=15 $ min, concentration from 0.1m to 0.025 will fall in 2 half lives so total time taken $ =2\times {T_{1/2}}=2\times 15=30 $ min.
