Question

How much oxygen is required tocombust 10 moles of magnesium

Answer 1

$2Mg + O_2 = 2MgO$

Thus, 2 moles of Mg requires 1 mole of oxygen for combustion.

Thus 1 mole of Mg requires = 1/2 = 0.5 moles

10 moles of Mg will require = 10 × 0.5 = 5 moles of oxygen.

mass of 5 moles of oxygen = 32×5 = 160g

Thus 10 moles of magnesium will need 5 moles of oxygen or 160g of oxygen for combustion.