Jamb chemistry 1, what mass of water is produced when 8.0g of hydrogen reacts with excess oxygen

The reaction between hydrogen and oxygen produces water.
2H₂(g) + O₂(g) → 2H₂O(l)

We'll use the molar masses: H = 1 g/mol, O = 16 g/mol.
Molar mass of H₂ = 2 × 1 g/mol = 2 g/mol
Moles of H₂ = Mass / Molar mass
Moles of H₂ = 8.0 g / 2 g/mol
Moles of H₂ = 4.0 mol

From the balanced equation, 2 moles of H₂ produce 2 moles of H₂O. This is a 1:1 mole ratio.
Moles of H₂O = Moles of H₂
Moles of H₂O = 4.0 mol

Molar mass of H₂O = (2 × 1 g/mol) + 16 g/mol = 18 g/mol
Mass of H₂O = Moles × Molar mass
Mass of H₂O = 4.0 mol × 18 g/mol
Mass of H₂O = 72 g

The mass of water produced is 72 g.