Acid Reactions

• Preparing a Salt from an acid + metal oxide


  1. Measure a set volume of an acid and place it into a beaker
  2. Using a Bunsen burner, gently warm the acid until bubbles first appear, then stop heating straight away
  3. Add a set mass of the metal oxide and stir to dissolve; continue adding the solid until no more will dissolve
  4. Once cool, filter the mixture into a conical flask
  5. Pour the solution into an evaporating dish and heat gently until about half of the liquid has evaporated
  6. Leave to crystallise
• Preparing a Salt from an Acid and Metal Carbonate


  1. Measure a set volume of an acid and place it into a beaker
  2. Add a set mass of the, metal carbonate and stir to dissolve; continue adding until no more will dissolve
  3. Filter the mixture into a conical flask
  4. Pour the solution into an evaporating dish and heat gently until about half of the liquid has evaporated
  5. Leave to crystallise
• Strong Acids Dissociating


  Hydrochloric acid: monoprotic

  HCl (aq) -> H⁺ (aq) + Cl⁻(aq)

  Sulfuric acid: diprotic

  H₂SO₄(aq) -> 2H⁺(aq) + SO₄²⁻(aq)

  Nitric acid: monoprotic

  HNO₃(aq) -> H⁺(aq) + NO₃⁻(aq)

  Phosphoric acid: triprotic

  H₃PO₄(aq) -> 3H⁺(aq) + PO₄³⁻(aq)
• Weak Acids Dissociating

  Weak acids partially dissociate in a solution. In equilibrium, products are formed at the same time reactants are used- both reactants and products are present in a solution

  (same applies to weak bases)

  Example: ethanoic acid

  CH3COOH (aq) ⇌ CH3COO- (aq) + H+ (aq)
• Acid reactions


  • Acid + metal -> Salt + Hydrogen REDOX
  • d
  • c
• What does a base neutralising an acid form?

  A salt
• Strong acids


  Hydrochloric acid - HCl

  Sulfuric acid - H₂SO₄

  Nitric acid - HNO₃
• Weak acid


  Ethanoic acid - CH₃COOH
• Neutralisation reaction


  Acid + Base -> Salt + Water
• Acid + Metal -> Salt + Hydrogen (redox)
• Acid + Metal Oxide -> Salt + Water
• Acid + Metal hydroxide -> Salt + Water
• Acid + Carbonate -> Salt + water + Carbon dioxide
• Acid + Ammonia -> Salt
• Acid with Metals

  Faster reactions:

  • More effervescence
  • Metal dissolves faster
  • More exothermic

  General Equation:

  Acid (aq) + Metal (s) -> Salt + Hydrogen

  Observations: Metal dissolves + fizzing
• Acid with Metal Oxide

  General Equation:

  Acid (aq) + Metal Oxide (s) -> Salt + water

  Observations: Metal Oxide solid dissolves