15. Consider the following two reactions: \mathbf{A} \rightarrow 2 \mathbf{B} \quad \Delta H^{\circ}_{\mathbf{R} n}=456.7 \mathbf{k J} / \mathrm{mol} \mathbf{A} \rightarrow \mathbf{C} \quad \Delta \mathrm{H}^{\circ}{ }_{\mathrm{rxn}}=-22.1 \mathrm{~kJ} / \mathrm{mol} Determine the

enthalpy change for the process: 2B — С A) -478.8 kJ/mol B) -434.6 kJ/mol C) 434.6 kJ/mol D) 478.8 kJ/mol E) More information is needed to solve the problem.