Chapter 9, Problem 9.15P

Water gas is the name for the mixture of CO and $H_2$ prepared by reaction of steam with carbon at $\text{1000°C:}$
$\text{C}\left(\text{s}\right){\text{+H}}_{\text{2}}\text{O}\left(\text{g}\right)\to \text{CO}\left(\text{g}\right){\text{+H}}_{\text{2}}\left(\text{g}\right)$
"Water gas"
The hydrogen is then purified and used as a starting material for preparing ammonia. Use the following information to calculate $\Delta H°$ in kilojoules for the water-gas reaction:
$C\left(s\right)+O_2\left(g\right)\to C{O}_2\left(g\right)$ $\Delta H°=-3\text{93}\text{.5 kJ}$
$2CO\left(g\right)+O_2\left(g\right)\to 2C{O}_2\left(g\right)$ $\Delta H°=-566.\text{0 kJ}$
$2H_2\left(g\right)+O_2\left(g\right)\to 2H_{2}O\left(g\right)$ $\Delta H°=-48\text{3}\text{.6 kJ}$