Question

Q.3 In a first order reaction, the concentration of reactant decreases from
20 mmol dm to 8 mmol dm in 38 minutes. What is the half life of
reaction?​

Answer 1

Answer

Given data,

in a first order of reaction

The concentration of reactant decreases from 20 mmol dm to 8 mmol dm in 38 minutes

Time =38 min

K=2.303/t log10 a/a-x

We need to calculate the value of k

Using formula of rate constant of reaction

Put the value into the formula

We need to calculate the half life of reaction

Using formula of half life

Put the value of k

Hence, The half life of reaction is 1732.5 sec.