The unit of the rate constant depends on which of the following?

For a gaseous reaction $2A + B \rightarrow C + D$,the rate of reaction is given by $Rate = K[A][B]$. If the volume of the container is reduced to $1/4$ of its original volume,what will be the ratio of the new rate to the original rate?

The possible mechanism for the reaction $2NO + Br_2 \to 2NOBr$ is:
$NO + Br_2 \rightleftharpoons NOBr_2$ (Fast)
$NOBr_2 + NO \to 2NOBr$ (Slow)
The rate law expression is:

For a reaction,$AB_5 \to AB + 4B$,the rate can be expressed in the following ways:
$-\frac{d[AB_5]}{dt} = K[AB_5]$ ; $\frac{d[B]}{dt} = K_1[AB_5]$
What is the correct relation between $K$ and $K_1$?

The value of the rate constant of a pseudo first order reaction:

The differential form of the rate equation is given by:
$dx/dt = k[P][Q]^{0.5}[R]^{0.5}$
Which statement about the above equation is wrong?