LAQ : How many litres of oxygen is needed to burn completely 2.2 g propone (C3H8)?

Question

How many litres of oxygen is needed to burn completely 2.2 g propone (C3H₈)?

Answer

Balanced chemical equation:

C₃H₈ + 5O₂ = 3CO₂ + 4H₂O

Molecular Mass of C₃H₈ = 12 × 3 + 1 × 8 = 44 g

Volume of 5O₂ = 5 × 22.4 = 112 L

Clearly, 44 g of propane burns completely in 112 L of oxygen

∴ To burn 2.2g of propane completely, the amount of oxygen needed is (112×2.2)/44 = 5.6 L