Chapter 4 - Analysing acids and bases

CHAPTER 4 - ANALYSING ACIDS AND BASES acids are proton donors, bases are proton acceptors acid-base reactions involve a transfer of protons from the acid to the base the conjugate base of an acid has one less proton than the acid an acid will react with a base to form a salt plus water when the base reacting with an acid is a carbonate or a hydrogen carbonate, the products are carbon dioxide as well as a salt and water pH is a measure of the concentration of H3O+ ions in an aqueous solution the concentration of acidic or basic solutions can be determined by volumetric analysis the indicator used in an acid-base titration must provide a sharp end point the end point in an acid-base titration must be at or close to the equivalence point back titrations are used to analyse solutions of weak acids or bases where indicators do not produce a shapr end point an excess of a strong acid or base is added to the chemical that is to be analysed and the amount of excess in then determined by titration a strong acid completely ionises a weak acid only partially ionises pH=-log[H30+] END POINT: colour changes EQUIVALENCE POINT: the point at which, during titration, the solutions have been mixed to their molar ratios

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