Lecture Notes: Reactions between Acids and Bases

Overview

• Focus on reactions between acids and different kinds of bases.
• Types of bases discussed: metal oxides, metal hydroxides, and metal carbonates.
• These reactions are classified as neutralization reactions.
• Process for making soluble salts using an insoluble base is covered.

Metal Oxides and Hydroxides

• Reaction with acids forms a salt and water.
• Example Reactions:
  • Hydrochloric acid + Sodium oxide:
    • Results in Sodium chloride (salt) and water.
  • Sulfuric acid + Potassium hydroxide:
    • Results in Potassium sulfate (K2SO4) and water.
• Reaction Pattern:
  • Negative ion from the acid combines with the positive ion from the base to form a salt.
  • Always produces water.
  • Importance of correct balancing and salt formula.

Metal Carbonates

• Reaction with acids forms a salt, water, and carbon dioxide (CO2).
• Example Reaction:
  • Nitric acid + Calcium carbonate:
    • Results in Calcium nitrate (salt), water, and CO2.
  • Requires balancing due to differing charges (e.g., nitrate 1- and calcium 2+).

Making Soluble Salts with Insoluble Bases

• Procedure:
  1. Place dilute acid in a beaker and gently heat with a Bunsen burner.
  2. Add insoluble base (e.g., copper oxide) incrementally until no longer reacts.
  3. Filter excess base using filter paper and funnel.
  4. Evaporate water gently using a water bath or electric heater.
  5. Allow solution to cool to form crystals.
  6. Filter and dry crystals to obtain pure salt.

Important Points

• Soluble salts dissolve in water.
• Insoluble base reacts with acid to produce a soluble salt.
• Careful temperature control during evaporation to prevent damage to salts.
• Final steps involve crystallization, filtration, and drying.

Conclusion

• Utilizing different types of bases with acids leads to different byproducts.
• Understanding the procedure for creating soluble salts is crucial for practical applications.
• Always ensure correct reactions, balancing, and safe laboratory practices.