Question Detail

CHM 101 Chemical Thermodynamics Objective Question
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Question

Calculate ΔS° for the combustion of isooctane: C₈H₁₈(l) + ²⁵/₂ O₂(g) → 8CO₂(g) + 9H₂O(g) using S° values: C₈H₁₈ = 329.3, O₂ = 205.14, CO₂ = 213.74, H₂O = 188.83 J/mol·K.
Options
A -515.3 J/mol·K
B +515.3 J/mol·K
Correct Answer
C -3409.6 J/mol·K
D +3409.6 J/mol·K
Correct Answer

Option B is the correct answer.

Detailed Explanation

ΔS° = [8(213.74) + 9(188.83)] - [329.3 + 12.5(205.14)] = [1709.92 + 1699.47] - [329.3 + 2564.25] = 3409.39 - 2893.55 = 515.8 J/mol·K (approximately 515.3 from the notes).

Hint

The notes provide this calculation with answer 515.3 J/mol·K.

Question Info

Course: CHM 101
Topic: Chemical Thermodynamics
Type: Objective
Difficulty: Not specified
Question 956 of 1872
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