UNIT OVERVIEW

In Term 2, you explored reactions in aqueous solution — precipitation reactions, acid-base reactions, and redox reactions. Now we introduce one of chemistry's most powerful tools: stoichiometry and the mole concept.

Stoichiometry lets you predict exactly how much of each substance is involved in a reaction. Think of it like a recipe: you need to know the right amounts of each ingredient to get the result you want.

In this unit, you will learn:

• What a mole is and why chemists use this counting unit
• Avogadro's number and how it connects tiny particles to measurable amounts
• How to calculate molar mass using the periodic table
• How to convert between moles, mass, and number of particles
• How to use balanced equations to calculate quantities in reactions
• How to work with concentration in solutions

Why this matters:

• Pharmacists calculate exact amounts of medicine ingredients
• Water treatment plants work out how much chlorine to add for safe drinking water
• Fertilizer factories need precise ratios to produce useful products

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