MOHR'S METHOD
Principle
Chlorides are estimated as sodium chloride by titration against silver nitrate using potassium chromate as indicator. Silver nitrate is added until all the chloride ions present in the SAMPLE WATER have combined with the silver ions. Any further silver nitrate added is now free to combine with the potassium chromate indicator to yield a red precipitate of silver chromate. The solution at this point suddenly changes from pale yellow to faint brick-red colour.
NaCl + AgNO3→AgCl + NaNO3