Strong acids and weak acids

• Strong Acids


  Sulfuric, hydrochloric and nitric acids that ionise completely in water
• Weak Acids


  Ethanoic, citric and carbonic acids that do not fully ionise in solution
• Ionisation of acids


  1. Reversible reaction

  2. Equilibrium between undissociated and dissociated acid particles

  3. Only a small proportion of acid particles dissociate to release H+ ions
• Concentration of H+ ions


  Affects rate of reaction with other substances
• Strong acids


  More reactive than weak acids of the same concentration
• pH


  Measure of the concentration of hydrogen ions in a solution
• For every 1 unit decrease in pH, the concentration of H+ ions increases by a factor of 10
• For a decrease of 2 on the pH scale, the concentration of H+ ions increases by a factor of 100
• Concentration of an acid


  Refers to the total amount of acid molecules in a given volume of solution, not the strength (strong or weak)
• Concentration of an acid determines the total number of acid molecules, not the proportion that are ionised
• Concentration of H+ ions will decrease with dilution, whether it's a strong or weak acid
• Strong acids are strong because they let go of all their H+ ions, weak acids are weak because only a small proportion of their H+ ions are released