Advertisements
Advertisements
Question
Explain why often coloured spots are formed on clothes during washing.
Advertisements
Solution
The laundry, skincare, beauty, and personal hygiene products that we use commonly can cause stains and color changes in our clothes. Toothpaste, perspiration, facial soap, deodorants, hair sprays, strong perfumes with alcohol, and even rain are often the causes of stains on garments. All these stains may eventually dry up, not causing any visible stain; however, age and exposure to heat will cause them to reappear.
RELATED QUESTIONS
In a locality, hard water, required for an experiment, is not available. However, the following salts are available in the school laboratory:
1. Sodium sulphate
2. Calcium sulphate
3. Magnesium chloride
4. Sodium chloride
5. Calcium chloride
6. Potassium sulphate
Which of the above salts may be dissolved in water to obtain hard water for the experiment?
(A) 2, 3 and 5
(B) 1, 2 and 5
(C) 1, 2, 4 and 6
(D) 3 and 5 only
Hard water is not available for an experiment. Some salts are given below :
(I) Sodium chloride
(II) Sodium sulphate
(III) Calcium chloride
(IV) Calcium sulphate
(V) Potassium chloride
(VI) Magnesium sulphate
Select from the following group of these salts, each member of which may be dissolved in water to make it hard.
(A) I, II, V
(B) I, III, V
(C) III, IV, VI
(D) II, IV, VI
Why is soap not suitable for washing clothes when the water is hard?
What is a detergent? Name one detergent.
Explain the cleansing action of soap. Draw diagrams to illustrate your answer.
Soap is a salt of ______ and sodium hydroxide.
Match the following
| 1. | Soap | C6H5 OH |
| 2. | Cement | CaSO4.2H2O |
| 3. | Fertilizers | NaOH |
| 4. | Gypsum | RCC |
| 5. | Phenol | NPK |
Analogy:
Used to join components: Adhesives:: Clean the body ______.
______ to remove strong strains on the clothes.
______ are substances which can undergo chemical changes to produce certain materials.
