Question

Total order of reaction $X+Y⟶XY$ is $3$. The order of reaction with respect to $X$ is $2$. State the differential rate equation for the reaction.

• A. $-\frac{d\left[X\right]}{dt}=K{\left[X\right]}^3{\left[Y\right]}^0$
• B. $-\frac{d\left[X\right]}{dt}=K{\left[X\right]}^0{\left[Y\right]}^3$
• C. $-\frac{d\left[X\right]}{dt}=K{\left[X\right]}^2{\left[Y\right]}^{}$
• D. $-\frac{d\left[X\right]}{dt}=K{\left[X\right]}^{}{\left[Y\right]}^2$

Answer 1

The correct option is A $-\frac{d\left[X\right]}{dt}=K{\left[X\right]}^3{\left[Y\right]}^0$

The molecularity is 2 so X when no influence from Y due to Zeroth order will become:

$-\frac{d\left[X\right]}{dt}=k[X{]}^2.[X]=k[X{]}^3$