ConceptConceptDocsDocuments

A-Level Edexcel Chemistry Total Entropy and Feasibility

Review A-Level Edexcel Chemistry total entropy through feasibility decisions from system and surroundings entropy values in data tables.

Syllabus
First assessment 2019
Course
Chemistry YCH11
Level
A2

Exam points

  • select feasible reactions by adding system and surroundings entropy changes

12.10—Reactions can occur as long as ∆Stotal is positive even if one of the other entropy changes is negative question 1

[Maximum number: 2]

This question is about oxides of iron.

The equation for the reduction of iron(III) oxide by carbon monoxide is shown.

Fe2O3( s)+3CO( g)→2Fe( s)+3CO2( g)ΔH⊖=−24.8 kJ mol−1\mathrm{Fe}_{2} \mathrm{O}_{3}(\mathrm{~s})+3 \mathrm{CO}(\mathrm{~g}) \rightarrow 2 \mathrm{Fe}(\mathrm{~s})+3 \mathrm{CO}_{2}(\mathrm{~g}) \quad \Delta H^{\ominus}=-24.8 \mathrm{~kJ} \mathrm{~mol}^{-1}

The entropy change, ΔSsystem ⊖\Delta S_{\text {system }}^{\ominus}, for this reaction is +15.2 J mol−1 K−1+15.2 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}.

Explain why the reaction should be feasible at any temperature.

All question bank results loaded