Question

For a first order reaction, $A(g) \rightarrow B(g)$ at $35^{\circ} C$, the volume of $A$ left in reaction vessel at various times are given below. [Given data : $\log (5 / 4)=0.096$. What is the value of rate constant?

• A. 0.02231 $\min^{-1}$
• B. 0.04231 $\min^{-1}$
• C. 0.06231 $\min^{-1}$
• D. 0.08231 $\min^{-1}$

Answer 1

Answer: (A)

0.02231 $\min^{-1}$

Answer 2

For a first order reaction,

$A(g) \longrightarrow B(g) \text { at } 35^{\circ} C$

The rate constant $k$ is expressed as

$K =\frac{2303}{t} \log \frac{ C _{0}}{ C }=\frac{2303}{10} \log \frac{25}{20}$
$=\frac{2303}{10} \log \frac{5}{4}=\frac{2303}{10} \times 0.096$
$=0.0221\, \min ^{-1} \simeq 0.02231\, \min ^{-1}$