How much heat is released when 44.1 g of propane is burned?

Question

The reaction for the combustion of propane is

How much heat is released when  of propane is burned?

C3H8(g)+5O2(g)⟶3CO2(g)+4H2O(l)Δ𝐻=−526.3kcalmol

Answer 1

C₃H₈(g) + 5O₂(g) ==.> 3CO₂(g) + 4H₂O(l) ... Δ𝐻=−526.3 kcal/mol

This tells you that 526.3 kcal are released when 1 mol of C₃H₈ is combusted with 5 mols O₂.

How many mols C₃H₈ are present in 44.1 g?

molar mass C₃H₈ = 44.1 g/mol

44.1 g x 1 mol / 44.1 g = 1.00 mols propane

heat released = 1.00 mol C₃H₈ x 526.3 kcal/mol = 526.3 kcal of heat releaseed

(note: you don't need a minus sign in front of the value if you say "released". Otherwise, you'd write -562.3 kcal