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CHM 101 CHM 101 Past Questions Objective Question
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Question

The standard enthalpy changes of formation of H₂(g) and N₂(g) is 0. Calculate the standard enthalpy change of the following reaction: N₂(g) + 3H₂(g) → 2NH₃(g). Given: ΔH_f, NH₃(g) = -45.9 kJ/mol
Options
A -45.9 kJ/mol
B -92.0 kJ/mol
C -91.8 kJ/mol
Correct Answer
D -92.8 kJ/mol
Correct Answer

Option C is the correct answer.

Detailed Explanation

ΔH°_rxn = 2 × ΔH_f(NH₃) - [ΔH_f(N₂) + 3ΔH_f(H₂)] = 2×(-45.9) - (0+0) = -91.8 kJ/mol.

Hint

Use ΔH°_rxn = Σ ΔH_f(products) - Σ ΔH_f(reactants).

Question Info

Course: CHM 101
Topic: CHM 101 Past Questions
Type: Objective
Difficulty: Not specified
Question 1761 of 1872
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