UNIT OVERVIEW

Acid-base reactions happen all around you every day. The sour taste of lemon juice comes from citric acid. The slippery feel of soap comes from a base. When you take an antacid for heartburn, you are using an acid-base reaction to neutralise excess stomach acid.

In this unit, you will learn how scientists define acids and bases, and why they behave the way they do. At the heart of acid-base chemistry is a simple idea: protons (H⁺ ions) moving between molecules.

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

• Define acids and bases using both the Arrhenius and Brønsted-Lowry theories
• Identify conjugate acid-base pairs in chemical reactions
• Recognise and explain amphoteric substances
• Distinguish between strong and weak acids and bases
• Understand the pH scale and calculate pH values
• Explain the auto-ionisation of water and the significance of $K_w$
• Perform calculations involving neutralisation reactions
• Understand and apply acid-base titration techniques

Real-life applications: