GCSE Chemistry Unit 3 Revision (6)

Acids, Alkalis and Titrations

• Acids can be strong or weak.
• Strong acids like sulphuric acid ionise almost completely in water. 
• This means almost every hydrogen atom is released to become a hydrated proton. (A large number of H+ (aq) ions are formed
• Weak acids like citric acid ionise only very slightly.
• This means only some of the hydrogen atoms in the compound are released, so a small number of H+ (aq) ions are formed.
• The pH of an acid or alkali is a measure of the concentration of H+ (aq) ions in a solution.
• Strong acids typically have a pH f about 1 or 2, whilst the pH of a weak acid could be 5 or 6.
• The pH of an acid or alkali can be measured with a pH meter or with universal indicator…