Question

For reaction, $aA⟶xP$, when $\left[A\right]=2.2$ $m$ $M$, the rate was found to be $2.4$ $m$ $M$ $s^{-1}$. On reducing concentration of $A$ to half, the rate changes to $0.6$ $m$ $M$ $s^{-1}$. The order of reaction with respect to $A$ is:

• A. $1.5$
• B. $2.0$
• C. $2.5$
• D. $3.0$

Answer 1

The correct option is B $2.0$

Rate $=k{\left[A\right]}^a$

$2.4=k{\left[2.2\right]}^a$ ...(i)
$0.6=k{\left[1.1\right]}^a$ ...(ii)

Dividing equation (i) by equation (ii), $a=2$ $\therefore$ order $=2$