Determine the heat given off to the surroundings when 9.0 g of aluminum reacts according to the equation 2al + fe2o3 → al2o3 + 2fe, δh°rxn = - 849 kj/mol.

From the balanced chemical reaction, 849 kJ of heat is released for every 2 moles of Al, therefore calculate the moles of Al reacted:

moles Al = 9g / (26.98 g/mol)

moles Al = 0.33 mol

The total heat released is:

total heat = (-849 kj/2mol) * (0.33 mol)

total heat = - 141.6 kJ