What mass of propane (c3h8 (g)) must be burned to supply 2775 kj of heat? the standard enthalpy of combustion of propane at 298 k is - 2220 kj · mol-1?

Question

Chemistry

Zachary Lawrence

21 March, 03:21

What mass of propane (c3h8 (g)) must be burned to supply 2775 kj of heat? the standard enthalpy of combustion of propane at 298 k is - 2220 kj · mol-1?

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Dante Melton · Answer 1

Answer is: 55.125 grams of propane must be burned.

Balanced chemical reaction: C₃H₈ + 5O₂ → 3CO₂ + 4H₂O.

Make proportion: 1 mol (C₃H₈) : 2220 kJ = n (C₃H₈) : 2775kJ.

n (C₃H₈) = 2775 kJ·mol : 2220 kJ.

n (C₃H₈) = 1.25 mol.

m (C₃H₈) = n (C₃H₈) · M (C₃H₈).

m (C₃H₈) = 1.25 mol · 44.1 g/mol.

m (C₃H₈) = 55.125 g.

n - amount of substance.