Question

The following data are obtained for a reaction, $X+Y\to Products$.

Expt.	$\left[X_0\right]/mol$	$\left[Y_0\right]/mol$	rate / mol $L^{-1}{s}^{-1}$
1	0.25	0.25	$1.0\times {10}^{-6}$
2	0.50	0.25	$4.0\times {10}^{-6}$
3	0.25	0.50	$8.0\times {10}^{-6}$

The overall order of the reaction is:

• A. 2
• B. 4
• C. 3
• D. 5

Answer 1

The correct option is D 5

$R_1=k\left[Xo{]}^m\right[Y_0{]}^n=k\left[0.25{]}^m\right[0.25{]}^n$ ....(1)

$R_2=k\left[Xo{]}^m\right[Y_0{]}^n=k\left[0.50{]}^m\right[0.25{]}^n$ ....(2)

$R_3=k\left[Xo{]}^m\right[Y_0{]}^n=k\left[0.25{]}^m\right[0.50{]}^n$ ....(3)

Dividing (2) by (1), we get

$4=2^m\Rightarrow m=2$

Dividing (3) by (1), we get

$8=2^n\Rightarrow n=3$

Overall order $=(m+n)=5$