Question

For the first order reaction the rate constant is 6.93 *10-3 then the half life is

Answer 1

The question has not mentioned the units for the value of rate constant. It is assumed that the rate constant is in s⁻¹

Answer: -

The half life refers to the amount of time needed for concentration of a reactant to decrease by half with respect to its initial concentration. Its application is used in chemistry and medicine to predict the changes in concentration of a substance over time. It has important applications in drug industry and nuclear science.

For a first order reaction,

The rate constant k and the half life t1/2 are related by the relation

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

      = $\frac{0.693}{6.93x10-3}$

     = 1000 s

Thus the half life is 1000 s

Answer 2

Answer: 100

Explanation:

Half life is the time taken by a reactant to reduce to its original concentration. It is designated by the symbol $t_\frac{1}{2}$.

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

$\lambda$ = rate constant  = $6.93\times 10^{-3}$

$t_\frac{1}{2}$ = half life

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

${t_{\frac{1}{2}}}=\frac{0.693}{6.93\times 10^{-3}}=100$

The half life is 100.