Chemical Kinetics Question 177
Question: 75% of a first order reaction is completed in 30 minutes. What is the time required for 93.75% of the reaction (in minutes) [KCET 2001]
Options:
A) 45
B) 120
C) 90
D) 60
Show Answer
Answer:
Correct Answer: D
Solution:
$ k=\frac{2.303}{t}\log ( \frac{a}{a-x} ) $ ; $ k=\frac{2.303}{30}\log ( \frac{100}{100-75} ) $
$ k=\frac{2.303}{t}\log ( \frac{100}{100-93.75} ) $ Put the value of $ K $ from above equation we get the value of $ t $ therefore
$ \therefore \ \ \ t=60,\min . $
