Chemistry - Hydrocarbon Question with Solution | TestHub

$\begin{array}{rl}& {\mathrm{C}}_5{\mathrm{H}}_{12(g)}+8{\mathrm{O}}_{2(9)}⟶5{\mathrm{CO}}_{2(g)}+6{\mathrm{H}}_2{\mathrm{O}}_{(\mathrm{e})}\\ & \therefore \Delta {\mathrm{G}}_r=5{\left(\Delta {\mathrm{G}}_r\right)}_{{\mathrm{CO}}_2}+6{\left(\Delta {\mathrm{G}}_{\mathrm{r}}\right)}_{{\mathrm{H}}_2\mathrm{O}}-{\left(\Delta {\mathrm{G}}_{\mathrm{r}}\right)}_{\text{Pentane }}\\ & =5(-5394.4)+6(-237.2)-(-8.2)\\ & =-1972-1423.2+8.2\\ & \Delta {\mathrm{G}}_{\mathrm{R}}=-3387\mathrm{kJ}/\mathrm{mole}\\ & {\mathrm{C}}_5^{\frac{-12}{5}}{\mathrm{H}}_{12}⟶5\stackrel{4}{{\mathrm{C}}_2}\end{array}$ For 5 carbon atoms, there is a change of electrons from - 12 to 20 $\begin{array}{rl}& \therefore \text{ No. of electrons involved }=32{\mathrm{e}}^{-}\\ & \Delta G_r=-3387\times 10^3=-32\times E^{\circ }\times 96500\\ & E^{\circ }=1.097V\end{array}$