Question 10:
Explain the formation of scum when hard water is treated with soap.
Answer:
Soap does not work properly when the water is hard. A soap is a sodium or potassium
salt of long chain fatty acids. Hard water contains salts of calcium and magnesium.
When soap is added to hard water, calcium and magnesium ions present in water
displace sodium or potassium ions from the soap molecules forming an insoluble
substance called scum. A lot of soap is wasted in the process.
Latest Govt Job & Exam Updates: