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Electrolysis is the decomposition of a compound using electricity.
During electrolysis, electrical energy is converted into chemical energy to bring about a chemical change.
The apparatus used for electrolysis is called an Electrolytic Cell and it consists of 3 main components: Battery or Power Source, Electrodes and Electrolytes
It consists of two electrodes in an electrolyte.
An electrode is essentially a rod or plate where electricity enters or leaves an electrolyte during electrolysis.
An electrolyte could be an ionic compound in molten state or dissolved in aqueous solution, or an acid or alkali solution. Presence of mobile ions allows it to conducts an electric current and is decomposed in the electrolysis process.
A direct current power source or battery is connected to the electrodes.
An electric current will flow through the electrolyte, decomposing it into simpler substances.
Cathode is the negative electrode connected to the negative terminal of the battery or power source.
Anode is the positive electrode connected to the positive terminal of the battery or power source.
Cation, which is an ion having a positive charge, will be attracted to the negatively charged cathode and gets reduced.
Anion, which is an ion having a negative charge, will be attracted to the positively charged anode and gets oxidised.
Note that during electrolysis, reactions only occur at the electrodes and not inside the electrolyte.
The reaction which takes place during electrolysis is a redox reaction:
Oxidation occurs at the anode while reduction occurs at the cathode.
Strategy (acronym) to remember: AN OX; RED CAT For more O Level Pure Chemistry. IP Chemistry learning resources, go to www.SimpleChemConcepts.com
20 апр 2018
