Overview
This lecture covers how acids react with different bases (metal oxides, hydroxides, carbonates) in neutralization reactions, and outlines the steps to make soluble salts using insoluble bases.
Acid Reactions with Metal Oxides and Hydroxides
- Acids react with metal oxides or metal hydroxides to form a salt and water.
- Example: Hydrochloric acid + sodium oxide → sodium chloride (salt) + water.
- Example: Sulfuric acid + potassium hydroxide → potassium sulfate (salt) + water.
- The salt's formula combines the acid's negative ion with the base's positive ion.
- Always check and balance the final chemical equation.
Acid Reactions with Metal Carbonates
- Acids react with metal carbonates to form a salt, water, and carbon dioxide.
- Example: Nitric acid + calcium carbonate → calcium nitrate (salt) + water + carbon dioxide.
- Balance charges to form correct salt formulas, then balance the full equation.
Making Soluble Salts from Insoluble Bases
- Soluble salts can be made by reacting an acid with an insoluble base (oxide, hydroxide, carbonate).
- Add dilute acid to a beaker and gently heat.
- Add the insoluble base in small amounts until no more dissolves (base in excess).
- Filter out unreacted base using filter paper and funnel.
- Gently heat the filtrate to evaporate some water until crystals of salt form.
- Allow the solution to cool; more crystals will form.
- Filter and dry the crystals to obtain pure, solid salt.
Key Terms & Definitions
- Neutralization reaction — a chemical reaction where an acid and a base form a salt and water.
- Salt — an ionic compound formed from acid-base reactions.
- Soluble salt — a salt that dissolves in water.
- Insoluble base — a base that does not dissolve in water.
Action Items / Next Steps
- Review the steps for preparing a soluble salt in laboratory practice.
- Practice writing and balancing equations for acid reactions with bases and carbonates.