Question

Below is the thermochemical equation for the combustion of octane.

SC8H18(l) + 25O2(g) ⇒ 16CO2 (g) + 18H2O(l), ΔH= -10,941kj


How much heat is released during the combustion of 4 moles of octane (C8H18)

Question 5 options:

-21,882 kJ


-175,056 kJ


-2,735 kJ


-10,941 kJ


Impossible to answer this question with the information provided


-5,470.5 kJ

Answer 1

5mol produces -10.941KJ

4 mol let produces x KJ

Solve through proportion

• 5/-10.941=4/x
• 5x=-43.764
• x=-43.764/5
• x=8.756 KJ

Answer 2

5moles of octane produces -10941KJ

1mol of octane produces 2188KJ

4mol of octane produces

• 2188(4)
• 8756KJ