What indicator is used in the Argentometric method for measuring chloride?

The Argentometric method for measuring chloride specifically relies on the use of chromate ions as an indicator. In this titration method, a solution of silver nitrate is used to precipitate chloride ions as silver chloride. Once all the chloride has reacted, excess silver ions will react with chromate ions to form a red-brown precipitate of silver chromate. This color change signals the endpoint of the titration, allowing for an accurate measurement of the chloride concentration in the sample.

The other choices do not serve as indicators in this method. Diphenyl carbazone is commonly used in other types of titrations but not in the Argentometric method. Cobaltous chloride and sulfide ions also do not play a role in this specific chloride measurement technique. Therefore, chromate ions are essential for indicating the completion of the reaction in the Argentometric determination of chloride ions.