Chapter 6, Problem 55E

Use standard enthalpies of formation to calculate $\Delta H_{\text{rxn}}^{\text{o}}$ for each reaction.

1. ${\text{C}}_{\text{2}}{\text{H}}_{\text{4}}\text{(}g{\text{)+H}}_{\text{2}}\text{(}g\text{)}\to {\text{C}}_{\text{2}}{\text{H}}_{\text{6}}\text{(}g\text{)}$
2. $\text{CO(}g{\text{)+H}}_{\text{2}}\text{O(}g\text{)}\to {\text{H}}_{\text{2}}\text{(}g{\text{)+CO}}_{\text{2}}\text{(}g\text{)}$
3. ${\text{3NO}}_{\text{2}}\text{(}g{\text{)+H}}_{\text{2}}\text{O(}l\text{)}\to {\text{2HNO}}_{\text{3}}\text{(}aq\text{)+NO}$
4. ${\text{Cr}}_{\text{2}}{\text{O}}_{\text{3}}\text{(}s\text{)+3CO(}g\text{)}\to \text{2Cr(}s{\text{)+3CO}}_{\text{2}}\text{(}g\text{)}$