Electrolysis

For Edexcel iGCSE this is essential knowledge of electrolysis. This is a good website for explaining further: https://www.nagwa.com/en/explainers/172172026301/

when do ionic compounds conduct electricity?

IONIC COMPOUNDS

• molten or aqueous conducts because the ions are free to move

• solid the ions are in a fixed lattice structure and are NOT free to move

electrolysis

electrolysis is the splitting up of a compound by the passage of a current.

why do metals conduct?

Metals conduct electricity as they have a sea of delocalised electrons which are free to move.

anode

anode - a POSITIVELY CHARGED electrode which anions go to

cathode

cathode - a NEGATIVELY CHARGED electrode which cations go to

OIL RIG

• Oxidation

• Is

• Loss of electrons

• Reduction

• Is

• Gain of electrons

SILVER

is not a colour in chemistry

halogen at ANODE

2Cl^-_(aq) → Cl_2^(g) + 2e^-

dilute/no halogen at ANODE

4OH^-_(aq) → O_2^(g) + 2H₂O_^(l) + 4e^-

at CATHODE

least reactive element is produced

• copper less reactive than hydrogen

• electrolysis of CuCl₂

• at CATHODE Cu^2+_(aq) + 2e^- → Cu_^(s)

• COMMON 2H^+_(s) + 2e^- = H_2(g)