Question

The gaseous reaction, $A\left(g\right)\to 2B\left(g\right)+C\left(g\right)$ is found to be first order with respect to A. If the reaction is started with PA = 90mm Hg, the pressure after 10 min is found to be 180 mm Hg. The rate constant of the reaction

• A. $1.15\times {10}^{-3}{s}^{-1}$
• B. $2.30\times {10}^{-3}{s}^{-1}$
• C. $0.0690s^{-1}$
• D. $4.60\times {10}^{-3}{s}^{-1}$

Answer 1

The correct option is A $1.15\times {10}^{-3}{s}^{-1}$

$\begin{array}{cccc}& A_{\left(g\right)}\to & 2B_{\left(g\right)}+& C_{\left(g\right)}\\ t=0& 90& 0& 0\\ t=10min& 90-x& 2x& x\end{array}$
$\therefore 90+2x=180,x=45$
$k_1=\frac{2.303}{10\times 60}log\frac{90}{45}=1.15\times {10}^{-3}se{c}^{-1}$