Question

What will be the half-life period of a first order reaction with rate constant $k=5.5 \times 10^{-14} s^{-1}$ ?

• A. $1.26\times 10^{13}s$
• B. $2.16\times 10^{13}s$
• C. $1.26\times 10^{-13}s$
• D. $2.16\times 10^{-13}s$

Answer 1

Answer: (A)

$1.26\times 10^{13}s$

Answer 2

For the first order reaction, $\because t_{1 / 2}=\frac{0.693}{k}$ $\therefore=\frac{0.693}{5.5 \times 10^{-14} s^{-1}}$ $t_{1 / 2}=1.26 \times 10^{13} s$