Question

1. From the following heats of reactions that are given:
C(s) + O2 (g) --> CO2 (g) H = -393.5 kJ
2H2 (g) + O2 (g)--> 2H2O (l) H = -571.6 kJ
2C2H2 (g) + 5 O2 (g) --> 4CO2 (g) + 2H2O (l) H = -2598.8 kJ
Calculate the heat of the reaction of the following equation:
2C(s) + H2 (g) --> C2H2 (g)


2. Calculate the Hrxn for the following reaction:
2Al(s) + Fe2O3(s) --> 2Fe (s) + Al2O3(s)
Given that:
I. 2Al2O3 (s) --> 4Al (s) + 3O2(g) H= + 3339.6kJ
II. 4Fe(s) + 3O2(g) --> 2 Fe2O3(s) H= - 1644.4kJ


3. Nitrogen can exists as N2O, NH3, NO and NO2. In which compound is nitrogen in its
lowest oxidation state?