Question

Given the reaction $A+B\to C+D$, a catalyst, $X$, is used to increase the overall reaction and an intermediate, $Y$, is formed during the reaction.
Without actual data, which of the following is least likely to be the rate law for the reaction?

• A. $Rate=k\left[A\right]\left[B\right]$
• B. $Rate=k\left[A\right]\left[X\right]$
• C. $Rate=k\left[A\right]\left[Y\right]$
• D. $Rate=k$

Answer 1

The correct option is B $Rate=k\left[A\right]\left[X\right]$

The presence of catalyst $X$ only lowers the activation energy of reactant & thereby increasing the rate of reaction. But its concentration does not affect the rate equation.

$\therefore \left(B\right)$ Rate=$K\left[A\right]\left[X\right]$ is least likely to be the rate law for the reaction.