Acid

• Strong acid


  Completely dissociate (ionize)
• HSO4 24+ Sof
• How to distinguish strong and weak acids

  1. By measuring pH (pH meter, universal indicator)

  2. Electrical conductivity (strong > weak)

  3. Rate of reaction (strong > weak)
• Acid


  • 1. Acid + metal
  • 2. 2HCL + Mg → salt & hydrogen (less reactive Mg + (displacement))
• Dissociation at strong acids
• Weak acid


  Partially dissociate in water
• Dissociation of weak acids

  CH3COOH ⇌ CH3COO⁻ + H⁺
• Acid + Base


  1. Metal oxide

  2. Metal hydroxide

  3. Metal carbonate

  4. Ammonia

  5. H3O⁺ + OH⁻ → 2H₂O (neutralisation)
• Ca(NO3)2 + 12H₂O
• HCL + CaCO3


  CaCl2 + CO2 ↑
• HNO3 + NH3


  NH4NO3 (ammonium nitrate)
• (NH4)2SO4 (ammonium sulfate)
• Acid + metal sulfite


  Salt + water + sulfur dioxide
• 2HNO3 + Na2SO3
• Acid


  Proton donor (H+)
• Strong acid


  • Completely dissociate (ionize)
• Dissociation of strong acids

  H+ + A-
• Weak acid


  Partially dissociate
• Dissociation of weak acids

  HA ⇌ H+ + A-
• Weak acid dissociation


  H+ concentration increases, A- concentration decreases
• pH


  Measure of H+ concentration
• pH of strong acid is low (pH 1)
• Distinguishing strong and weak acids

  1. Measure pH

  2. Measure electrical conductivity

  3. Measure rate of reaction
• Acid-metal reaction


  Acid + metal → salt + hydrogen
• Acid-base reaction


  Acid + base → salt + water
• Acid-metal oxide/hydroxide/carbonate/ammonia reaction


  Acid + metal oxide/hydroxide/carbonate/ammonia → salt + water
• Acid-metal sulfite reaction


  2 acid + metal sulfite → salt + sulfur dioxide + water
• Acid ionization


  HA ⇌ H+ + A-
• Enthalpy change (ΔH) for acid ionization is negative
• Amphoteric


  Compound that can act as both an acid and a base
• Amphoteric oxides


  • Fe2O3
  • Al2O3
• Reaction of basic oxides with water


  Basic oxide + water → hydroxide
• Reaction of acidic oxides with water

  Acidic oxide + water → acid
• Acids have more H+ than OH- ions, resulting in a lower pH value.
• A solution with a pH of 7 is neutral because it has an equal number of hydrogen (H+) and hydroxide (OH-) ions.
• The pH scale is logarithmic, meaning that the difference between two adjacent values on the scale represents a tenfold change.