Acids, Carbonates, and Indigestion Remedies

Acids, Carbonates, and Indigestion Remedies

Year 11 Chemistry Understanding Neutralisation Reactions Conservation of Mass in Chemical Reactions

Learning Objectives & Success Criteria

Understand what acids and carbonates are Write word equations for neutralisation reactions Explain conservation of mass in chemical reactions Apply knowledge to indigestion remedies Success Criteria: Can identify reactants and products, balance equations, explain real-world applications

What Are Acids?

Substances that release hydrogen ions (H+) in water Have a pH less than 7 Common examples: hydrochloric acid (HCl), citric acid Taste sour (but never taste chemicals in lab!) React with metals and carbonates

What Are Carbonates?

Compounds containing the carbonate ion (CO₃²⁻) Common examples: calcium carbonate (CaCO₃), sodium carbonate Found in limestone, chalk, and antacid tablets React with acids to produce carbon dioxide gas Often appear as white powders or crystals

Identifying Acids and Carbonates

Work in pairs to categorize these substances: Lemon juice, Chalk, Vinegar, Baking soda, Battery acid, Limestone Create two columns: Acids vs Carbonates Discuss your reasoning with your partner Extension: Research pH values for each substance

The Neutralisation Reaction

When acids react with carbonates: Acid + Carbonate → Salt + Water + Carbon Dioxide Example: Hydrochloric acid + Calcium carbonate HCl + CaCO₃ → CaCl₂ + H₂O + CO₂ The acid is 'neutralised' by the carbonate

Think-Pair-Share

What do you notice about the number of atoms on each side of the equation? Discuss with your partner: Count the atoms of each element before and after What does this tell us about chemical reactions?

Conservation of Mass

In chemical reactions, atoms are neither created nor destroyed Total mass of reactants = Total mass of products Atoms are rearranged, not lost or gained This is why we balance chemical equations Discovered by Antoine Lavoisier in 1789

Balancing Chemical Equations

Indigestion: The Problem

Stomach produces hydrochloric acid (HCl) for digestion Sometimes too much acid causes discomfort Symptoms: burning sensation, pain, bloating Acid can damage stomach lining if excessive Need to neutralise excess acid safely

Indigestion Remedies: The Solution

Antacids contain carbonates or hydroxides Common ingredients: calcium carbonate, magnesium carbonate These neutralise excess stomach acid Reaction: HCl + CaCO₃ → CaCl₂ + H₂O + CO₂ The CO₂ gas produced may cause burping!

Design an Antacid

You're a pharmaceutical chemist! Choose a carbonate compound for your antacid Write the neutralisation equation with stomach acid Calculate how many grams neutralise 1g of HCl Design packaging with your chemical explanation Extension: Research side effects and dosage limits