19,879
edits
Changes
no edit summary
: When the [[Negative Ion|negative ions]] reach the [[anode]] they lose [[electron]]s to become [[atom]]s or [[Neutral (Charge)|neutral]] [[compound]]s.
: When the [[Positive Ion|positive ions]] reach the [[cathode]] they gain [[electron]]s to become [[atom]]s. However, in [[aqueous]] [[solution]] if the [[metal]] [[ion]]s are more [[reactivity|reactive]] than [[Hydrogen]] then [[Hydrogen]] [[gas]] will be [[product|produced]].
: To describe an [[electrolysis]] [[Chemical Reaction|reaction]] [[Half Equation|half equations]] are used.
===Examples===
[[Balanced Symbol Equation]]: 2Li<sub>2</sub>O → 4Li + O<sub>2</sub>
'''Half Equation''' at [[cathode]]: Li<sup>+</sup> + e<sup>-</sup> → Li
'''Half Equation''' at [[anode]]: 2O<sup>-2</sup> → O<sub>2</sub> + 4e<sup>-</sup>
{| class="wikitable"
| style="height:10px; width:200px; text-align:center;" |[[Balanced Symbol Equation]]
| style="height:10px; width:200px; text-align:center;" |'''2Li<sub>2</sub>O(l) → 4Li(l) + O<sub>2</sub>(g)'''
| style="height:10px; width:200px; text-align:center;" |'''CuCl<sub>2</sub>(aq) → Cu(s) + Cl<sub>2</sub>(g)'''
| style="height:10px; width:200px; text-align:center;" |'''2H<sub>2</sub>O(l) → 2H<sub>2</sub>(g) + O<sub>2</sub>(g)'''
|-
| style="height:10px; width:200px; text-align:center;" |'''Half Equation''' at [[cathode]]
| style="height:10px; width:200px; text-align:center;" |Li<sup>+</sup> + e<sup>-</sup> → Li
| style="height:10px; width:200px; text-align:center;" |Cu<sup>+2</sup>(aq) + 2e<sup>-</sup> → Cu(s)
| style="height:10px; width:200px; text-align:center;" |2H<sup>+</sup>(aq) + 2e<sup>-</sup> → H<sub>2</sub>(g)
|-
| style="height:10px; width:200px; text-align:center;" |'''Half Equation''' at [[anode]]
| style="height:10px; width:200px; text-align:center;" |2O<sup>-2</sup> → O<sub>2</sub> + 4e<sup>-</sup>
| style="height:10px; width:200px; text-align:center;" |2Cl<sup>-</sup>(aq) → Cl<sub>2</sub>(g) + 2e<sup>-</sup>
| style="height:10px; width:200px; text-align:center;" |4OH<sup>-</sup> → 2H<sub>2</sub>O(l) + O<sub>2</sub>(g) + 4e<sup>-</sup>
|}