Determine the heat given off to the surroundings when 9.0 g of aluminum reacts according to the equation 2Al + Fe₂O₃ $\rarr$Al₂O₃ + 2Fe, $\Delta$H°_rxn= -849 kJ/mol. A)1.4 × 10² kJ B)2.8 × 10² kJ C)5.6 × 10² kJ D)2.5 × 10³ kJ E)7.6 × 10³ kJ

Question

Quizplus · Accepted Answer

The molar mass of aluminum (Al) is approximately 27 g/mol. For 9.0 g of Al, the moles of Al are 9.0 g / 27 g/mol = 0.333 mol. The reaction involves 2 moles of Al, so the heat released is (0.333 mol / 2 mol) × 849 kJ/mol = 141.5 kJ, which is approximately 1.4 × 10² kJ.

Determine the Heat Given Off to the Surroundings When 9 →\rarr→

Determine the Heat Given Off to the Surroundings When 9 $\rarr$