Units of rate constant of first and zero order reactions in terms of molarity unit are respectively

The rate law from a reaction between the substances $\mathrm{A}$ and $\mathrm{B}$ Is given by:

rate $=\mathrm{k}\left[\mathrm{A}{]}^{\mathrm{n}}\right[\mathrm{B}{]}^{\mathrm{m}}$

On doubling the concentration of $\mathrm{A}$ And halving the concentration of $\mathrm{B}$, the ratio of the new rate to the earlier rate of the reaction will be as:

For the reaction system,

$2\mathrm{NO}\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)⟶2{\mathrm{NO}}_2\left(\mathrm{g}\right)$ volume is suddenly reduced to half its value by increasing the pressure on it. If the reaction is of first order with respect to ${\mathrm{O}}_2$ and second order with respect to $\mathrm{NO},$ the rate of reaction will: