Question

For the reaction system $2NO\left(g\right)+O_2\left(g\right)\to 2N{O}_2\left(g\right)$ volume is suddenly reduced to half of its value by increasing the pressure on it. If the reaction is first order with respect to $O_2$ and second order with respect to $NO$, the rate of reaction will:

• A. increase to four times of its initial value
• B. diminish to one-fourth of its initial value
• C. diminish to one-eight of its initial value
• D. increase to eight times of its initial value

Answer 1

The correct option is D increase to eight times of its initial value

For this sudden change.

$PV=$ Constant.

$\therefore P_1{V}_1=P_2{V}_2$

$V_2=\frac{V_1}{2}\Rightarrow P_2={2P}_1$

Hence, the pressure got doubled.

For gaseous reaction, the concentration is directly proportional to pressure.

Given,

Rate = $K\left[O_2\right]{\left[NO\right]}^2$

It pressure of both reactants gets doubled, the new rate will become 8 times of its initial value.