Magnesium burns in air with a dazzling brilliance to produce magnesium oxide:
2Mg(s) + O₂(g) → 2MgO(s)
When 4.00 g of magnesium burns,the theoretical yield of magnesium oxide is ________ g.

Question

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg(s)+ O₂(g)→ 2MgO(s) When 4.00 g of magnesium burns,the theoretical yield of magnesium oxide is ________ g.

Quizplus · Accepted Answer

The molar mass of Mg is 24.31 g/mol, and MgO is 40.31 g/mol. For 4.00 g of Mg, moles = 4.00 g / 24.31 g/mol = 0.1645 mol. The reaction produces an equal number of moles of MgO, so mass of MgO = 0.1645 mol * 40.31 g/mol = 6.63 g.

Magnesium Burns in Air with a Dazzling Brilliance to Produce