Question

A sample of ‘soft soap’ contains
A. Caesium
B. Potassium
C. Calcium
D. Magnesium

Answer 1

We know that soap is salt of potassium and sodium of higher fatty acid and it is represented as ${\rm{RCO}}{{\rm{O}}^ - }{\rm{N}}{{\rm{a}}^ + }$. It possesses cleansing properties and is thus used in various purposes. The process of manufacturing g soap is termed as saponification.

Complete step by step answer:
Let’s first understand the process of saponification. It is the process in which an ester undergoes hydrolysis with potassium hydroxide (KOH) or sodium hydroxide (NaOH) to produce salt of sodium or potassium (soap) and alcohol. There are many uses of saponification reactions such as manufacturing hard and soft soaps, wet chemical fire extinguishers etc.
Now we discuss soft soaps in detail. Soft soap is soap that exists in liquid state rather than the solid one. It is usually prepared by the saponification of potassium instead of sodium hydroxide with triglycerides (vegetable oils and animal fats). And the hard soap forms when triglycerides undergo saponification with sodium hydroxide.
So, the soft soap contains potassium.

Hence, the correct choice is option B.

Additional Information:
There are various advantages and disadvantages of soaps.
Advantages:
1)Soaps are easily available
2)Soap are cheaper
3)The are eco friendly
4)They can be degraded by the microbes
Disadvantages:
1)They works in soft water not in hard water
2)Their cleansing action is less as compared to the detergents.

Note: There are many benefits of soft soap over hard soap. They give the skin moisturizing benefits along with great fragrances, they also make skin smooth and soft. Nowadays, soft soaps are used by the majority of households.