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CHM 101 CHM 101 Past Questions Objective Question
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Question

Which statement is true for the combustion of ethanol? C₂H₅OH(l) + 3O₂(g) → 2CO₂(g) + 3H₂O(l) with ΔH = -1370 kJ
Options
A The reaction is endothermic.
B The products occupy a smaller volume than the reactants
Correct Answer
C The enthalpy of the products is lower than the potential energy of the reactants.
D The enthalpy change would be the same if gaseous water were produced.
Correct Answer

Option B is the correct answer.

Detailed Explanation

Reactants: 3 moles gas (O₂). Products: 2 moles gas (CO₂). So products occupy a smaller volume. ΔH negative means exothermic, so products have lower enthalpy. If H₂O(g) were produced, ΔH would be less negative (energy needed to vaporize water).

Hint

Count the moles of gas on each side.

Question Info

Course: CHM 101
Topic: CHM 101 Past Questions
Type: Objective
Difficulty: Not specified
Question 1120 of 1872
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