Question

State true or false
Soft soaps are potassium salts of higher fatty acids.
(A) true
(B) false

Answer 1

Hint: The definition of surface actives or surfactants. These are the chemical substances that concentrate at the surface of the solution and form surface films. They reduce the surface tension of the solution and help in removing the dirt particles.

Complete step by step solution:
Soaps are sodium potassium salts of higher fatty acid that is lauric acid ($$\mathrm{C}_{11} \mathrm{H}_{23} \mathrm{COOH}$$), palmitic acid ($$\mathrm{C}_{15} \mathrm{H}_{31} \mathrm{COOH}$$), stearic acid ($$\mathrm{C}_{17} \mathrm{H}_{35} \mathrm{COOH}$$), etc. Soaps are formed by heating fat/oil (glyceryl esters of fatty acids) with aqueous solution of sodium hydroxide solution. This reaction is called Saponification.
During the process of hydrolysis, the esters of fatty acids are hydrolysed and the soap is obtained in the colloidal form and floats in solution as crude. It is precipitated from the solution by adding solution and sodium chloride. When the soap is removed from the solution, then a precipitate solution is left behind. It is called lye. It contains glycerol which can be obtained by the process of fractional distillation. Therefore, only potassium and sodium soaps are soluble in water and used for cleaning purposes. Generally, potassium soaps are softer for skin than the sodium soaps. These are prepared by hydrolysis by aqueous potassium hydroxide instead of sodium hydroxide.
Additional information: Soaps are biodegradable, and cause no harm to nature. Different raw materials could be used to make different soaps. But the disadvantage is that it can never be used in hard water and acidic solution.

The answer is (A) which is True.

Note: Soaps have relatively weaker cleansing action than detergents. The molecules of surfactant have a water-soluble and the other in soil soluble.