What are detergents chemically? List two merits and two demerits of using detergents for cleansing. State the reason for the suitability of detergents for washing, even in the case of water having calcium and magnesium ions.
The long chain of carboxylic acids contains ammonium or sulphonate salts are called detergents. Detergents do not lose their potency in hard water. Detergents do not form scum.
Example: Sodium lauryl sulfate
Two merits of detergents:
(i) In hard water detergents work very well.
(ii) The solubility of detergents is greater than soaps in water.
Two demerits of detergents:
(i) Synthetical detergents are non-biodegradable.
(ii) Detergents cause severe health problems.
Detergents are generally sulphonate or ammonium salts of long-chain carboxylic acids which do not react with Calcium () and Magnesium () ions in hard water.
So, detergents do not produce insoluble precipitate with Calcium and Magnesium ions and no scum is formed. Therefore, the detergent remains effective in hard water.