If 10.0 L of ethene gas at STP is completely polymerised to polyethylene, calculate the mass of polyethylene formed. (Molar mass of repeating unit C₂H₄ = 28 g mol∑, assume polymer contains the same number of repeating units as moles of ethene reacted).

Step-by-step solution

1. Determine moles of ethene: 10.0 L ÷ 22.4 L mol∑ = 0.4464 mol.
2. Each mole of ethene gives one repeating unit in the polymer.
3. Total moles of repeating units = 0.4464 mol.
4. Mass of polyethylene = 0.4464 mol × 28 g mol∑ = 12.5 g.
5. – Therefore 12.5 g of polyethylene is produced.

Concept tested: Polymerisation mass calculation

Published 10 October 2026 · How this solution was prepared and checked