(a) Soaps are basically sodium or potassium salts of long chain fatty acids. They are usually prepared using NaOH/KOH and fatty acid esters. The acidic or basic strength of soap depends upon the relative acidic/basic strength of the reactants used. In most cases, NaOH is used which is highly basic. Hence, soap solutions are generally basic in nature and turn red litmus blue.

(b) Temporary hardness is produced by the presence of bicarbonate ions of calcium, magnesium etc. Temporary hardness of water can be removed by heating. One can also use washing soda (sodium carbonate) to remove temporary hardness of water.