Consider an electrochemical cell: $\text{A}\left(\text{s}\right)\left|{\text{ A}}^{\text{n+}}\left(\text{aq, 2 M}\right)\right|\left|{\text{ B}}^{\text{2n+}}\left(\text{aq, 1 M}\right)\right|\text{ B}\left(\text{s}\right)$. The value of ${\text{ΔH}}^{\text{o}}$ for the cell reaction is twice that of ${\text{ΔG}}^{\text{o}}$ at $\text{300 K}\text{.}$ If the emf of the cell is zero, the magnitude of $\mathrm{\Delta }{\text{S}}^o$ $\left(\text{in} {\text{J}}^{-1}{\text{K}}^{-1} {\text{mol}}^{-1}\right)$ of the cell reaction per mole of $\text{B}$ formed at $\text{300}\text{K}$ is ____
(Given: R $\text{=}\text{8}\text{.3}{\text{JK}}^{-\text{1}}{\text{mol}}^{-1}.$ $\text{H,}\text{S}$ and $\text{G}$ are enthalpy, entropy and Gibbs energy, respectively.)

Hence, the correct answer is -11.62.