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