UNIT OVERVIEW

This unit covers electrochemical reactions — the chemistry of electron transfer. Every time you start a car, charge your phone, or see gold-plated jewellery being made, electrochemistry is at work.

Electrochemistry connects chemical reactions to electrical energy. You will learn how chemical reactions can produce electricity (galvanic cells) and how electricity can drive chemical reactions (electrolytic cells).

By the end of this unit, you will be able to:

• Explain the structure and operation of electrolytic cells and galvanic cells
• Write and balance half-reactions at anodes and cathodes
• Use standard electrode potentials to predict spontaneous reactions
• Calculate cell potentials using $E°_{cell} = E°_{cathode} - E°_{anode}$
• Use oxidation numbers to balance redox equations
• Describe real-world applications including batteries, fuel cells, electroplating, and the chlor-alkali process

Why This Matters:

• Car batteries use galvanic cells to convert chemical energy to electrical energy
• Electroplating in the jewellery industry coats base metals with gold or silver using electrolytic cells
• The chlor-alkali process produces chlorine and sodium hydroxide for water purification and cleaning products
• Rechargeable batteries in inverters and phones are reversible electrochemical cells
• Fuel cells convert hydrogen and oxygen directly into electricity and water

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