Chemical Kinetics Question 2
Question 2 - 2024 (01 Feb Shift 2)
The following data were obtained during the first order thermal decomposition of a gas A at constant volume:
$\mathrm{A}(\mathrm{g}) \rightarrow 2 \mathrm{~B}(\mathrm{~g})+\mathrm{C}(\mathrm{g})$
| S.No | Time/s | Total pressure/(atm) |
|---|---|---|
| 1. | $\quad 0$ | 0.1 |
| 2. | $\quad 115$ | 0.28 |
The rate constant of the reaction is ___________ $\times 10^{-2} \mathrm{~s}^{-1}$ (nearest integer)
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Answer (2)
Solution
$$ \mathrm{A}(\mathrm{g}) \rightarrow 2 \mathrm{~B}(\mathrm{~g})+\mathrm{C}(\mathrm{g}) $$
$\mathrm{t}=0$
0.1
$\mathrm{t}=115$ sec $\quad 0.1-x \quad \quad 2 \mathrm{x}\quad\quad \mathrm{x}$
$0.1+2 \mathrm{x}=0.28$
$2 \mathrm{x}=0.18$
$\mathrm{x}=0.09$
$\mathrm{K}=\frac{1}{115} \ln \frac{0.1 \mathrm{~m}}{0.1-0.09}$
$=0.0200 \mathrm{sec}^{-1}$
$=2 \times 10^{-2} \mathrm{sec}^{-1}$
