How much energy is evolved during the reaction of 53.4 g of Al,according to the reaction below? Assume that there is excess Fe₂O₃. Fe₂O₃(s)+ 2 Al(s)→ Al₂O₃(s)+ 2 Fe(s)ΔH°_rxn= -852 kJ A) 53.4 kJ B) 430 kJ C) 215 kJ D) 1686 kJ E) 843 kJ

Question

Quizplus · Accepted Answer

The molar mass of Al is 26.98 g/mol. The reaction involves 2 moles of Al, so 53.4 g of Al is 53.4 / 26.98 = 1.98 moles. The reaction releases 852 kJ for 2 moles of Al, so for 1.98 moles, the energy evolved is (1.98 / 2) * 852 kJ = 843 kJ.

How Much Energy Is Evolved During the Reaction of 53