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Question
Explain why often coloured spots are formed on clothes during washing.
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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
State one advantage of soaps over detergents.
What is saponification? Write the chemical equation of the reaction involved in this process. Name all the substances which take part in this process and also those which are formed.
The chemical which is not required for the preparation of soap in the laboratory is:
(a) vegetable oil
(b) baking soda
(c) caustic soda
(d) common salt
A student is testing water to know which is best for cleansing purposes with soaps. He would find that the cleansing action of soaps is best when he uses water obtained from
(a) rain
(b) tap
(c) hand pump
(d) pond
What are detergents chemically? List two merits and two demerits of using detergents for cleansing. State the reason for the suitability of detergents for washing, event in the case of water having calcium and magnesium ions.
Give a scientific explanation.
Soap forms a precipitate in hard water.
What is the difference between soaps and detergents? State, in brief, the cleansing action of soaps in removing an oily spot from a fabric. Why are soaps not very effective when a fabric is washed in hard water? How is this problem resolved?
What is meant by ‘surface activity’?
Arrange the following statements in correct sequence
- Pour that solution into an empty matchbox, soap can be obtained after drying.
- Take the necessary quantity of water in a jar.
- Then add coconut oil drop by drop and stir it well.
- Add concentrated sodium hydroxide in the jar and allow it to cool.
- Try this soap to wash your hand kerchief.
- Cover your work area with old newspaper.
______ to remove strong strains on the clothes.
