Answer
a. $-445.5 \text{ kJ}$
b. $-445.5 \text{ kJ}$
Work Step by Step
a. The reaction shows that for every two moles of $H_2O$, -891 kJ of energy is released. Therefore, for every mole $H_2O$, $\frac{-891}{2}=-445.5$ kJ is released.
b. The reaction shows that for every two moles of $O_2$ consumed, $-891$ kJ is released. Therefore, for every mole of $O_2$, $\frac{-891}{2}=-445.5$ kJ is released.
