General Chemistry 1: Enthalpy

4 Fe(s) + 3O$_2$(g) $\longrightarrow$ 2 Fe$_2$O$_3$(s) $\triangle$H = -1640 kJ

How many kJ of heat can be produced from 50.0g iron?

Find the enthalpy of reaction, $\triangle$H$_{rxn}$ , for the combustion of sugar (there is usually a table of enthalpies of formation in the back of chemistry textbooks)

C$_6$H$_{12}$O$_6$ (s) + 6 O$_2$ (g) $\longrightarrow$ 6 CO$_2$ (g) + 6 H$_2$O (l)