Understanding Acid-Base Reactions and Predicting Products
Dot-Point 3: predict the products of acid reactions and write balanced equations to represent acids and bases, acids and carbonates, acids and metals (ACSCH067)
Acid-base reactions are essential in chemistry, and they can be predicted based on the types of substances involved. These reactions often result in the formation of salts, water, and sometimes gases. In this post, we’ll explore the three main types of acid reactions:
Acid + Base → Salt + Water (Neutralization)
Acid + Carbonate → Salt + Water + Carbon Dioxide
Acid + Active Metal → Salt + Hydrogen Gas
We’ll go through the reactions with examples and balance the chemical equations for each.
1. Acid + Base → Salt + Water (Neutralization)
In a neutralization reaction, an acid reacts with a base to form a salt and water. This occurs when hydrogen ions (H+) from the acid combine with hydroxide ions (OH-) from the base to form water.
Example: Acetic acid reacts with calcium hydroxide
Acetic acid (CH₃COOH) reacts with calcium hydroxide (Ca(OH)₂).
The products are calcium acetate (Ca(CH₃COO)₂) and water (H₂O).
Balanced Equation:
2. Acid + Carbonate → Salt + Water + Carbon Dioxide
When an acid reacts with a carbonate, it produces a salt, water, and carbon dioxide gas. The reaction typically involves the release of carbon dioxide.
Example: Sulfuric acid reacts with copper carbonate
Sulfuric acid (H₂SO₄) reacts with copper carbonate (CuCO₃).
The products are copper sulfate (CuSO₄), water (H₂O), and carbon dioxide (CO₂).
Balanced Equation:
3. Acid + Active Metal → Salt + Hydrogen Gas
When an acid reacts with an active metal, it forms a salt and hydrogen gas. The metal undergoes oxidation, losing electrons.
Example: Phosphoric acid reacts with sodium
Phosphoric acid (H₃PO₄) reacts with sodium (Na).
The products are sodium phosphate (Na₃PO₄) and hydrogen gas (H₂).
Balanced Equation:
4. Acid + Base → Salt + Water (Neutralization) (Again)
Example: Citric acid reacts with potassium hydroxide
Citric acid (C₆H₈O₇) reacts with potassium hydroxide (KOH).
The products are potassium citrate (K₃C₆H₅O₇) and water (H₂O).
Balanced Equation:
5. Acid + Base → Salt + Water (Neutralization) (One More Time)
Example: Nitric acid reacts with ammonia
Nitric acid (HNO₃) reacts with ammonia (NH₃).
The products are ammonium nitrate (NH₄NO₃) and water (H₂O).
Balanced Equation:
