IGCSE Chemistry
2026 - 2028
Syllabus Checklist ✅
Topic 9: Electrochemistry – Electrolysis & Hydrogen–Oxygen Fuel Cells
Electrolysis – Core Ideas
Define electrolysis
as the decomposition
of an ionic compound
, when molten
or in aqueous solution
, by the passage of an electric current
Identify in simple electrolytic cells: (a) the anode
as the positive electrode
(b) the cathode
as the negative electrode
(c) the electrolyte
as the molten/aqueous substance that undergoes electrolysis
Describe the transfer of charge during electrolysis: (a) movement of electrons
in the external circuit
(b) loss or gain of electrons
at the electrodes ( oxidation
/ reduction
) (c) movement of ions
in the electrolyte
Electrolysis – Case Studies (Inert Pt / C electrodes)
Identify products & observations for molten lead(II) bromide (PbBr₂)
using inert electrodes
Identify products & observations for concentrated aqueous NaCl
using inert electrodes
Identify products & observations for dilute H₂SO₄ (aq)
using inert electrodes
State that metals or hydrogen
are formed at the cathode
and that non-metals
(other than hydrogen) are formed at the anode
Predict products at each electrode for the electrolysis of a binary molten compound
Identify products & observations for aqueous CuSO₄
with inert carbon/graphite
electrodes and when using copper
electrodes
Predict products at each electrode for the electrolysis of a halide solution
in dilute
vs concentrated
conditions
Construct ionic half-equations
for reactions at the anode
(oxidation) and at the cathode
(reduction)
Electroplating
State that metal objects are electroplated
to improve appearance
and resistance to corrosion
Describe how metals are electroplated
(choice of electrolyte
, anode
of plating metal or inert, cathode
as object, correct polarity)
Hydrogen–Oxygen Fuel Cells
State that a hydrogen–oxygen fuel cell
uses H₂
and O₂
to produce electricity
with water
as the only chemical product
Describe the advantages
and disadvantages
of H₂–O₂ fuel cells vs gasoline/petrol engines
in vehicles
