Answer to Question #71138 in General Chemistry for Emily C

Question

2 C2H6 + 7 O2 --> 4 CO2 + 6 H2O ΔH = -385 kJ


How much heat is released when 77.90 grams of C2H6 reacts?

Answer 1

Considering that ΔH is given for chemical equation (i.e. for two moles of C2H6):
Molar mass of C2H6: 30 g/mol
Amount of C2H6: 77.90 / 30 = 2.6 mol
Energy released: (2.6 / 2) ∙ (-ΔH) = 500 kJ
Answer:
500 kJ