Question

For this reaction, C₃H₈(g) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O, the ΔH is –2200 kJ. If two moles of C₃H₈(g) reacted with excess oxygen, which of the following would be true?

a) 2750 kJ of heat is released.
b) 5500 kJ of heat is absorbed.
c) 2750 kJ of heat is absorbed.
d) 5500 kJ of heat is released.

Answer 1

For two moles of C₃H₈(g) reacting in the provided chemical reaction, 4400 kJ of heat would be released, not 2750 kJ or 5500 kJ as provided in the options.

Step-by-step explanation:

To solve this question, we need to consider the stoichiometry of the given reaction and the given value of ΔH. The balanced chemical equation, C₃H₈(g) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O, tells us that one mole of propane reacts with five moles of oxygen to produce three moles of carbon dioxide and four moles of water, releasing -2200 kJ of heat. Since this amount of heat is released for one mole of propane, for two moles of propane (× 2), the heat released would be × 2.

Therefore, -2200 kJ × 2 = -4400 kJ. The correct answer is that 4400 kJ of heat is released, but since none of the provided options match this result, it seems there is an error in the question. The closest correct option, if it were available, would be that 4400 kJ of heat is released.