Q. Find the two third life $(t_{1/2})$of a first order reaction in which $k = 5.48 \times 10^{- 14}$per second
A) $201 \times 10^{13}s$
B) $2.01 \times 10^{13}s$
C) $201 \times 10^{20}s$
D) $0.201 \times 10^{10}s$
Explanation
(b)
Let ,initial concentration=a
Final concentration=a- $\frac{2}{3}$ a= $\frac{a}{3}$
$t_{\frac{2}{3}} = \frac{2.303}{k}\log\frac{a}{a/3}$
$= \frac{2.303}{5.48 \times 10^{- 14}}\log 3$
=2.01$\times 10^{13}s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.