Question

The heat of formation of Fe2O3(s) is -826.0 kJ/mol. If a 53.99-g sample of iron is reacted, what is the approximate heat of the reaction?

A) -798.5 kJ
B) -199.6 kJ
C) -399.2 kJ
D) -1597 kJ

Answer 1

The approximate heat of the reaction can be found using the heat of formation and the balanced chemical equation.

Step-by-step explanation:

To find the approximate heat of the reaction, we can use the information given in the balanced chemical equation and the heat of formation of Fe2O3(s). The balanced chemical equation is 2 Al(s) + Fe₂O3(s) → 2 Fe(s) + Al₂O3(s) +815.5 kJ. From this equation, we can see that 2 mol of Fe₂O3(s) reacts with 815.5 kJ of heat produced. Therefore, the approximate heat of the reaction for a 53.99-g sample of iron is (-826.0 kJ/mol * 53.99 g)/159.7 g/mol ~ -279.48 kJ. Therefore, the correct answer is option D) -1597 kJ.