Order of Reaction Questions

Which one of the following statements for the order of a reaction is INCORRECT?

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

The bromination of acetone that occurs in acid solution is represented by the equation ${\text{CH}}_3{\text{COCH}}_3+{\text{Br}}_2\stackrel{{\text{H}}^{+}}{\to }{\text{CH}}_3{\text{COCH}}_2\text{Br}+{\text{H}}^{+}+{\text{Br}}^{-}$. Based on kinetic data showing the rate is independent of $[{\text{Br}}_2]$, what is the rate equation?

During the kinetic study of the reaction $2A+B\to C+D$, the following results were obtained:| Run | $[A]$ (M) | $[B]$ (M) | Initial Rate (${\text{mol L}}^{-1}{\text{min}}^{-1}$) ||---|---|---|---|| I | $0.1$ | $0.1$ | $6.0\times 10^{-3}$ || II | $0.3$ | $0.2$ | $7.2\times 10^{-2}$ || III | $0.3$ | $0.4$ | $2.88\times 10^{-1}$ || IV | $0.4$ | $0.1$ | $2.40\times 10^{-2}$ |Based on the above data which one of the following is correct?

The unit of rate constant for a zero order reaction is:

The decomposition of phosphine (${\text{PH}}_3$) on tungsten at low pressure is a first-order reaction. It is because the: