Advertisements
Advertisements
Question
Which of the two is better for washing clothes when the water is hard: soap or detergent? Give reason for your answer.
Solution
Detergent is better for washing clothes in hard water because it does not form insoluble magnesium or calcium salts (scum) on combining with the calcium or magnesium ions present in the hard water. Soap on the other hand reacts with these calcium and magnesium ions present in the hard water to form insoluble calcium and magnesium salts of fatty acids. Therefore, soaps don't lather easily in hard water, while detergents do.
APPEARS IN
RELATED QUESTIONS
Explain the formation of scum when hard water is treated with soap.
A student took four test tubes P, Q, R and S and filled about 8 mL of distilled water in each. After that he dissolved an equal amount of Na2SO4 in P, K2SO4 in Q, CaSO4 in R and MgSO4 in S. On adding an equal amount of soap solution and shaking each test tube well, a good amount of lather will be obtained in the test tubes:
(a) P and Q
(b) P and R
(c) P, Q and S
(d) Q, R and S
State one use of esterfication process.
Why is soap not suitable for washing clothes when the water is hard?
Answer the following question.
In three test tubes A, B, and C, three different liquids namely, distilled water, underground water and distilled water in which a pinch of calcium sulphate is dissolved, respectively are taken. Equal amount of soap Answer is added to each test tube and the contents are shaken. In which test tube will the length of the foam (lather) be longest? Justify your answer.
What is meant by 'surface activity'?
Explain why soap cannot be used in hard water.
The saponification of a fat or oil is done using _____ solution for hot process.
Analogy:
Used to join components: Adhesives:: Clean the body ______.
- Write the formula and draw electron dot structure of carbon tetrachloride.
- What is saponification? Write the reaction involved in this process.
