Answer to Question #345475 in General Chemistry for Han

Question

17.1 g of C2H6 is burned in oxygen. What mass of oxygen was consumed?(Assumed complete combustion). Show th solution.

Answer 1

Solution:

The molar mass of C₂H₆ is 30 g/mol

Therefore,

Moles of C₂H₆ = (17.1 g C₂H₆) × (1 mol C₂H₆ / 30 g C₂H₆) = 0.57 mol C₂H₆

Balanced chemical equation:

2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O

According to stoichiometry:

2 mol of C₂H₆ react with 7 mol of O₂

Thus, 0.57 mol of C₂H₆ react with:

(0.57 mol C₂H₆) × (7 mol O₂ / 2 mol C₂H₆) = 1.995 mol O₂

The molar mass of O₂ is 32 g/mol

Therefore,

Mass of O₂ = (1.995 mol O₂) × (32 g O₂ / 1 mol O₂) = 63.84 g O₂ = 63.8 g O₂

Mass of O₂ = 63.8 g

Answer: 63.8 grams of oxygen was consumed