Chemical Kinetics - Result Question 36
####36. For a first order reaction $A \longrightarrow B$ the reaction rate at reactant concentration of $0.01 M$ is found to be $2.0 \times 10^{-5} mol L^{-1} s^{-1}$. The half life period of the reaction is
(a) $30 s$
(b) $220 s$
(c) $300 s$
(d) $347 s$
[2005]
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Solution:
- (d) Given $[A]=0.01 M$
Rate $=2.0 \times 10^{-5} mol L^{-1} S^{-1}$
For a first order reaction
Rate $=k[A]$
$k=\frac{2.0 \times 10^{-5}}{[0.01]}=2 \times 10^{-3}$
$t _{1 / 2}=\frac{0.693}{2 \times 10^{-3}}=347 sec$.
