The rate of reaction at unit concentration of reactants is called _____.

The rate law for the reaction,

$\mathrm{A}+2\mathrm{B}\stackrel{}{\to }$ Products is: rate = $\mathrm{k}[\mathrm{A}] [\mathrm{B}{]}^{\mathrm{2}}$ Rate of the reaction at $30º\mathrm{C}$ is found to be $0.125 \mathrm{M}/\mathrm{s}$, when $\left[\mathrm{A}\right] = 2.0 \mathrm{M}\text{ and} \left[\mathrm{B}\right] = 0.4 \mathrm{M}$. The rate constant $\mathrm{k}$ at this temperature is _____ ${\text{M}}^{\text{-2}}{\text{s}}^{\text{-1}}$.