Electrolysis of aqueous solutions Flashcards – AQA GCSE Combined Science: Trilogy (8464) — Chemistry — Higher

Which ions does water contribute during electrolysis of an aqueous solution?

Hydrogen ions and hydroxide ions.

What happens to positive ions at the cathode during electrolysis?

They gain electrons.

What happens to negative ions at the anode during electrolysis?

They lose electrons.

For electrolysis of an aqueous solution with inert electrodes, how does the metal’s reactivity relative to hydrogen determine the cathode product?

• Metal more reactive than hydrogen: hydrogen is produced from hydrogen ions.
• Metal less reactive than hydrogen: the metal is deposited.

For electrolysis of an aqueous solution with inert electrodes, how does the presence or absence of halide ions determine the anode product?

• Halide ions present: the halogen is produced.
• No halide ions: hydroxide ions are discharged, producing oxygen.