Exhibit 5-1 Consider the reaction of Magnesium with oxygen to form magnesium oxide and heat as shown below to answer the following problem(s):
2 Mg (s) + O 2 (g)→2 MgO (s) D H ° rxn = - 1204 kJ
-Refer to Exhibit 5-1. How much heat is released when 2.43 grams of Mg (s) reacts at constant pressure?
Molar Mass(Mg) = 24.3 g/mol

Question

Quizplus · Accepted Answer

The reaction releases -1204 kJ for 2 moles of Mg. For 2.43 g of Mg, which is 0.1 moles (2.43 g / 24.3 g/mol), the heat released is (0.1 moles / 2 moles) * -1204 kJ = -60.2 kJ.

Exhibit 5-1 Consider the Reaction of Magnesium with Oxygen to Form