KK3 - galvanic cells

Features of galvanic cells

• Converts chemical energy into electrical energy through spontaneous redox reactions

• Non-rechargeable

• When spontaneous redox reactions occur in the same container, energy released as heat (thermal energy)

• When spontaneous reactions occur in different contains, a complete circuit can be made so that electrons transferred flow through wire as ions flow through salt bridge

Anode

• Electrode where oxidation occurs

• Is negative in a galvanic cell

• Must be an electrically conductive material

• Can be either an inert or reactive material

Cathode

• Electrode where reduction occurs

• Is positive in a galvanic cell

• Must be an electrically conductive material

• Can be either an inert or reactive material

Electrolyte

• Ionic solution in each half-cell

Salt bridge

• Contains a dissolved ionic solution

• Completes the internal circuit

• Ionic compound selected must be soluble in water

• Ionic compound selected must not react with any other species in the cell

• Connects the solutions of two half–cells

• Are spectator ions in galvanic cell reactions

Wire

• Allows flow of electrons from the anode to the cathode in a galvanic cell

• Forms the external circuit