Question

For given first order reaction, the reactant reduces to 1/4th its initial value in 10 min. The rate constant of the reaction is

• A. $0.1386\text{ mi}\text{n}^{- 1}$
• B. $0.0693\text{ mi}\text{n}^{- 1}$
• C. $0.1386\text{ mol }\text{L}^{- 1}min^{- 1} \, $
• D. $0.0693\text{ mol }\text{L}^{- 1}min^{- 1} \, $

Answer 1

Answer: (A)

For the first order reaction,

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

Given, $t=10\text{ min}$

$a=a$

$a-x=\frac{a}{4}$

$k=\frac{2.303}{10}log \frac{a}{\frac{a}{4}}$

$=\frac{2.303 \times 2}{10}log 2$

$=0.1386\text{ mi}\text{n}^{- 1}$