10.1 Electrolysis

Define electrolysis

decomposition of an ionic compound using an electric current

During electrolysis:
> e- move in external c__
> ions move in e__
> OILRIG occurs

circuit, electrolyte

Define electrode

rod of metal/graphite where electric current flows into/out of electrolyte

Define electrolyte

ionic compound in molten/dissolved soln that conducts electricity

Define anode

+ve electrode

Define anion. What is it attracted to?

-ve charged ion, anode

Define cathode

-ve electrode

Define cation. What is it attracted to?

+ve charged ion, cathode

Acronym for which OILRIG at which electrode

red cat an ox

Soln type	Anode (+ve electrode)	Cathode (-ve electrode)
Molten	__ (-ve ion)	__ (+ve ion)

non-metal, metal

Soln type	Anode (+ve electrode)	Cathode (-ve electrode)
Aq	If halogen: Ø  Conc.: __ formed Ø  Dilute: __ formed	If below H: Ø  __ formed Ø  e.g. Cu, Ag, Au
	If not halogen (e.g. SO42-): Ø  __ formed	If above H: Ø  __ formed

halogen, o2, metal, o2, h2

Electrolysis of Lead Bromide

What is the ionic half eq at the -ve cathode (reduction)?

Pb2+ + 2e- -> Pb

Electrolysis of Lead Bromide

What is the ionic half eq at the +ve anode (oxidation)?

2Br- -> Br2 + 2e-

After electrolysis, O₂ was formed. (i.e. in aq, dilute halogen OR no halogen)

Write the ionic half eq for the anion (at +ve anode; 2H₂O →...)

2H₂O -> O₂ + 4H+ + 4e-

Electrolysis of b__ (conc. NaCl[aq])
> method: d__ c__
>> made of a__ & polymers

Write the ionic half eq at the -ve cathode

brine, diaphragm cell, abestos, 2H+ + 2e- -> H2

Uses of chlorine
> P__, w__ (pool), C₂ solvents, etc

PVC, water

Uses of NaOH
> Na salts, s__, organics, etc

soap

O₂ : H₂ ratio in electrolysis of dilute H₂SO₄

1:2