Overview
This lecture covers neutralization reactions between acids and various bases, including how to make soluble salts from insoluble bases.
Neutralization Reactions: Acids with Metal Oxides and Hydroxides
- Acids react with metal oxides and 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 is formed by combining the positive ion from the base with the negative ion from the acid.
- Correct salt formulas and balanced equations are essential in these reactions.
Acids with Metal Carbonates
- Acids reacting with metal carbonates produce a salt, water, and carbon dioxide.
- Example: Nitric acid + calcium carbonate → calcium nitrate (salt) + water + carbon dioxide.
- Always balance charges to write the correct salt formula.
Making Soluble Salts Using Insoluble Bases
- To make a soluble salt, react an acid with an insoluble base (metal oxide, hydroxide, or carbonate).
- Gently heat dilute acid in a beaker and add the insoluble base gradually.
- Stop adding base once excess remains, indicating all acid is neutralized.
- Filter out unreacted base to isolate the dissolved salt solution.
- Gently evaporate water (using a water bath or electric heater, not a Bunsen burner) until crystals form.
- Let the solution cool to form more crystals, then filter and dry the crystals.
Key Terms & Definitions
- Neutralization reaction — Acid and base react to form a salt and usually water.
- Salt — Ionic compound formed from the positive ion of a base and the negative ion of an acid.
- Insoluble base — A base that does not dissolve in water, such as certain metal oxides or carbonates.
- Soluble salt — A salt that dissolves in water.
Action Items / Next Steps
- Practice writing balanced equations for neutralization reactions involving acids and various bases.
- Review the procedure for preparing soluble salts from insoluble bases.