Question

The isomerization of methylisonitrile to acetonitrile CH3NC(g) → CH3CN(g) is first order in CH3NC. The rate constant for the reaction is 9.45 × 10-5 s-1 at 478 K. The half-life of the reaction when the initial [CH3NC] is 0.030 M is ________ s

Answer 1

Answer: The half-life of the reaction is 7333 seconds

Explanation:

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant

t = age of sample

a = let initial amount of the reactant

a - x = amount left after decay process  

a) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

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

$t_{\frac{1}{2}}=\frac{0.693}{9.45\times 10^{-5}}=7333s$

The half-life of the reaction is 7333 seconds