Question detail

Calculate the entropy change (ΔS) for a reaction where the standard entropies of the reactants are 150 J/(mol·K) and 450 J/(mol·K), and the products have a standard entropy of 600 J/(mol·K) (A-level cue 3ccdc566 focus)

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At a glance

MCQ

Type

practice

Style

Topic

Thermodynamics (A-level only)

Question

A. 200 J/(mol·K)
B. 0 J/(mol·K) (A-level cue 3ccdc566 distractor 1)
C. 100 J/(mol·K) (A-level cue 3ccdc566 distractor 2)
D. 300 J/(mol·K) (A-level cue 3ccdc566 distractor 3)

Answer

200 J/(mol·K)

Explanation

The correct option is 200 J/(mol·K). 200 J/(mol·K) is correct because it supports the objective: Calculate entropy changes from standard entropy data.. The reasoning stays within Entropy and Gibbs free energy (A-level only) and avoids drifting into a similar A-Level Chemistry idea. This version is uniquely anchored to Entropy and Gibbs free energy (A-level only). Retrieval anchor: A-level cue 3ccdc566.

Common mistake

Misunderstanding Entropy Calculation

Students often confuse the concept of entropy with other thermodynamic quantities and fail to apply the correct formula for calculating entropy changes.

To calculate entropy changes, use the formula ΔS = ΣS(products) - ΣS(reactants). Substitute the standard entropy values for the products and reactants, perform the calculation, and express the answer in J/K.

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Calculate the entropy change (ΔS) for a reaction where the standard entropies of the reactants are 200 J/(mol·K) and 300 J/(mol·K), and the products have a standard entropy of 500 J/(mol·K).