`DeltaH_f of Al_2O_3` = -1290 kj/mol
`DeltaH_f of CaO` = -675KJ/mol
`3CaO + 2Al to Al_2O_3 + 2Ca`
Calculate `DeltaH_f` for this reaction.

Given that : O(g) + e^(-) to O^(-)(g) DeltaH = -142 kJ "mol"^(-1) O(g) + 2e^(-) to O^(2-)(g) Delta H = + 712 kJ "mol"^(-1) what will be the DeltaH for the reaction: O^(-)(g) + e^(-) to O^(2-)(g)

Generally alkali metals form their oxides by an average increment of 6 kJ mol^(-1) K^(-1) in their entropies. If at 25^(@)C, Delta G_(f)^(@) of Al_(2)O_(3)(s)=-1582 kJ mol^(-1) , Delta H_(f)^(@) of Li_(2)O(s)=1244 kJ and Delta H_(f)^(@) of Na_(2)O(s)=1411 kJ . The aluminium oxide can be reduced to Al metal by

Delta H_(f)^(@) for Al_(2)O_(3) is -1670 KJ. Calculate the enthalpy change for the reaction 4Al+3O_(2)rarr 2Al_(2)O_(3)