Question

What mass of oxygen combines with 2.88 mol

of magnesium in the reaction
2 Mg(s) + O2(g) −→ 2 MgO(s)?
Answer in units of g.

Answer 1

46.08 g of O2

Step-by-step explanation:

The balanced chemical equation for the reaction shows that 1 mol of O2 reacts with 2 mol of Mg to form 2 mol of MgO.

Therefore, to calculate the mass of O2 that reacts with 2.88 mol of Mg, we need to use the mole ratio between Mg and O2.

Mole ratio of Mg to O2 is 2:1, meaning that for every 2 moles of Mg, 1 mole of O2 reacts.

So, for 2.88 mol of Mg, we need 1.44 mol of O2 (2.88 mol Mg x 1 mol O2 / 2 mol Mg).

The molar mass of O2 is 32 g/mol.

Therefore, the mass of O2 needed is:

mass = number of moles x molar mass = 1.44 mol x 32 g/mol = 46.08 g.

Therefore, 46.08 g of O2 is needed to react with 2.88 mol of Mg.