Question

The half-life period of a first order reaction having rate constant $k=0.231\times {10}^{-10}{s}^{-1}$ will be:

• A. $32\times {10}^{10}s$
• B. $2\times {10}^{10}s$
• C. $3\times {10}^{10}s$
• D. $3\times {10}^{-12}s$

Answer 1

The correct option is C $3\times {10}^{10}s$

The half-life of a first order reaction is:

$t_{1/2}=\frac{0.693}{k}$

$k=0.231\times {10}^{-10}{s}^{-1}$

So, $t_{1/2}=\frac{0.693}{0.231\times {10}^{-10}}$

$\Rightarrow t_{1/2}=3\times {10}^{10}s$