The rate expression for the reaction ${\mathrm{A}}_{\left(\mathrm{g}\right)}+{\mathrm{B}}_{\left(\mathrm{g}\right)}$ $\to {\mathrm{C}}_{\left(\mathrm{g}\right)}$is rate $={\mathrm{kC}}_{\mathrm{A}}^2{\mathrm{C}}_{\mathrm{B}}^{1/2}$. What changes in the initial concentrations of A and B will cause the rate of reaction to increase by a factor of eight?