Required Practical: Electrolysis of Aqueous Solutions (OCR GCSE Chemistry A (Gateway Science Suite)): Flashcards

Water produces $H^+$ and $OH^-$ ions that react at electrodes

$H^+$ and $OH^-$

Less reactive ion

$Cu^{2+}$ (copper less reactive than hydrogen)

Solid copper

$Cu^{2+}(aq) + 2e^- \rightarrow Cu(s)$

Oxygen gas (and water)

$H^+$ (sodium more reactive than hydrogen)

Hydrogen gas

$2H^+(aq) + 2e^- \rightarrow H_2(g)$

Chlorine gas

$2Cl^-(aq) \rightarrow Cl_2(g) + 2e^-$

When present (preferentially over $OH^-$)

If no halide ions present (produces oxygen gas)