Chemical Kinetics Question 190
Question: For a first order reaction velocity constant, $ K={10^{-3}}{s^{-1}} $ . Two third life for it would be [MP PET 2001; UPSEAT 2003]
Options:
A) 1100 s
B) 2200 s
C) 3300 s
D) 4400 s
Show Answer
Answer:
Correct Answer: C
Solution:
We know that $ k=\frac{2.303}{t}\log \frac{a}{a-x} $
$ {10^{-3}}=\frac{2.303}{t}\log \frac{a}{(a-\frac{2a}{3})},{10^{-3}}=\frac{2.303}{t}\log ,3 $
$ {10^{-3}}=\frac{2.303}{t}\times 0.4771,t=\frac{2.303\times 0.4771}{{10^{-3}}} $
$ =3300\sec $
