1.Magnesium oxide reacts slowly with water to form magnesium hydroxide. What would be the effect on the observed value for ∆H_rxn for the reaction of MgO if 10% of the MgO had reacted with water to form Mg(OH)2? Would the value be higher or lower? (Hint: you need to determine the ∆H value for the reaction of Mg(OH)2 with HCl from heat of formation data.)

and

2.Determine delta H of reaction for the following reactions using enthalpy of formation data:

Mg3N2(s) + 6H2O(l) = 3Mg(OH)2(s) + 2NH3(l)

Mg(OH)2(s) = MgO(s) + H2O