Aluminum metal can be produced by reducing solid aluminum oxide (Al2O3) with carbon (graphite). Carbon monoxide is the other product. What is the enthalpy change (∆H° in kJ) when 25.0 g of aluminum metal is produced in this manner? You will need to balance the chemical equation.

Answer 1

2Al2O3 + 3C ==> 4Al + 3CO2
25.0 g Al metal. Atomic mass Al = 27
You will need to calculate the dHrxn as above. So you look up dHo formation for CO2, Al metal (it is zero), C( it is zero) and Al2O3.
The dHo rxn = (n*dHo formation products) - (n*dHo formation reactants)
Then dHo rxn * (25.0/4*27) = ?