Chemical Kinetics Question 179
Question: A substance -A- decomposes by a first order reaction starting initially with [A] =2.00m and after 200 min [A] = 0.15m. For this reaction what is the value of k [AIIMS 2001]
Options:
A) $ 1.29\times {10^{-2}}{{\min }^{-1}} $
B) $ 2.29\times {10^{-2}}{{\min }^{-1}} $
C) $ 3.29\times {10^{-2}}{{\min }^{-1}} $
D) $ 4.40\times {10^{-2}}{{\min }^{-1}} $
Show Answer
Answer:
Correct Answer: A
Solution:
Given A = 2.00 m, t = 200 min and a(a-x) = 0.15 m we know
$ k=\frac{2.303}{t}\log \frac{a}{a-x}=\frac{2.303}{200}\log \frac{2.00}{0.15} $
$ =\frac{2.303}{200}\times (0.301+0.824)=1.29\times {10^{-2}}{{\min }^{-1}} $
