ConceptConceptDocsDocuments

Edexcel IAL Chemistry 16.19 hydrogen-oxygen fuel-cell electrode reactions

Decide which electrode is oxidation or reduction, then match the acidic or alkaline half-equation and remember electrons travel through the external circuit.

Syllabus
First assessment 2019
Course
Chemistry YCH11
Level
A2

Exam points

  • Choose alkaline fuel-cell half-equations such as H2 plus OH- forming water and electrons.
  • Identify electron-flow direction from the negative electrode through the external circuit.
  • Write or recognise the overall hydrogen-oxygen reaction as hydrogen plus oxygen forming water.

16.19—The electrode reactions that occur in a hydrogen-oxygen fuel cell Knowledge of hydrogen-oxygen fuel cells with both acidic question 1

[Maximum number: 1]

A hydrogen-oxygen fuel cell is used to provide electrical energy for an electric motor in a car.

The electrolyte in the fuel cell is acidic. What is the half-equation at the anode?

A

1/2O2( g)+2H+(aq)+2e−→H2O(l)1 / 2 \mathrm{O}_{2}(\mathrm{~g})+2 \mathrm{H}^{+}(\mathrm{aq})+2 \mathrm{e}^{-} \rightarrow \mathrm{H}_{2} \mathrm{O}(\mathrm{l})

B

H2O(l)→1/2O2( g)+2H+(aq)+2e−\mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \rightarrow 1 / 2 \mathrm{O}_{2}(\mathrm{~g})+2 \mathrm{H}^{+}(\mathrm{aq})+2 \mathrm{e}^{-}

C

H2( g)→2H+(aq)+2e−\mathrm{H}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{H}^{+}(\mathrm{aq})+2 \mathrm{e}^{-}

D

2H+(aq)+2e−→H2( g)2 \mathrm{H}^{+}(\mathrm{aq})+2 \mathrm{e}^{-} \rightarrow \mathrm{H}_{2}(\mathrm{~g})

All question bank results loaded