Sodium laurylsulphate `[CH_3 (CH_2 )_11 OSO_3Na]` is the more effective detergent than sodium propyl sulphate `[CH_3CH_2CH_2OSO_3Na]` in hard water. Why?

Explanation

In sodium propyl sulphate `[CH_3CH_2CH_2OSO_3Na]`, the hydrocarbon chain is only three carbon long chain which is not sufficient for the oil and grease to dissolve well. But, the hydrocarbon chain of sodium lauryl sulphate `[CH_3(CH_2 )OSO_3^(-)Na^+]` is long enough for complete dissolution of oil and grease. Therefore, sodium lauryl sulphate `[CH_3(CH_2)_11OSO_3^(-)Na^+]` more effective than sodium propyl sulphate as a detergent in hard water.