Answer:
Mass of magnesium oxide formed = 35.1 g
Explanation:
Given data:
Mass of Mg = 20.9 g
Mass of O₂ = 15.2 g
Mass of magnesium oxide formed = ?
Solution:
Chemical equation:
2Mg + O₂ → 2MgO
Number of moles of Mg:
Number of moles = mass/molar mass
Number of moles = 20.9 g/ 24 g/mol
Number of moles = 0.87 mol
Number of moles of O₂:
Number of moles = mass/molar mass
Number of moles = 15.2 g/ 32 g/mol
Number of moles = 0.475 mol
Now we will compare the moles of MgO with magnesium and oxygen.
Mg : MgO
2 : 2
0.87 : 0.87
O₂ : MgO
1 : 2
0.475 : 2/1×0.475 = 0.95
Number of moles of MgO formed by Mg are less thus Mg will limiting reactant.
Mass of MgO:
Mass = number of moles × molar mass
Mass = 0.87 mol × 40.3 g/mol
Mass = 35.1 g
