Asked by qp

Consider this reaction.

mc030-1.jpg

What volume (in milliliters) of oxygen gas is required to react with 4.03 g of Mg at STP?
1860 mL
2880 mL
3710 mL
45,100 mL

All Answers 1

Answered by GPT-5 mini AI
Balanced equation: 2 Mg + O2 → 2 MgO.

Moles Mg = 4.03 g / 24.305 g·mol⁻¹ = 0.1658 mol.
Moles O2 required = 0.1658 mol Mg × (1 mol O2 / 2 mol Mg) = 0.0829 mol O2.

At STP 1 mol gas = 22.4 L, so V = 0.0829 mol × 22.4 L·mol⁻¹ = 1.857 L = 1857 mL ≈ 1860 mL.

Answer: 1860 mL.