Why is agitation necessary to get clean clothes? - Science


 People use a variety of methods to wash clothes. Usually after adding the soap, they ‘beat’ the clothes on a stone, or beat it with a paddle, scrub with a brush or the mixture is agitated in a washing machine. Why is agitation necessary to get clean clothes?



A soap molecule has two parts namely hydrophobic and hydrophilic. With the help of these, it attaches to the grease or dirt particle and forms a cluster called micelle. These micelles remain suspended as a colloid. To remove these micelles, it is necessary to agitate clothes.

Concept: Soap
  Is there an error in this question or solution?
Chapter 4: Carbon and its Compounds - Intext Questions [Page 76]


NCERT Science Class 10
Chapter 4 Carbon and its Compounds
Intext Questions | Q 2 | Page 76

Video TutorialsVIEW ALL [2]


Differentiate between Toilet soap and Laundry soap.

List two problems that arise due to the use of detergents instead of soaps.

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


(D) II, IV, VI

Fill in the following blank with suitable word:

The sodium salt of a long chain fatty acid is called .............

Use of synthetic detergents causes pollution of water.


Give any two differences between soaps and detergents.


Describe the structure of a soap molecule with the help of a diagram.

In a soap micelle, the soap molecules are arranged radially with:
(a) ionic ends directed towards the centre and hydrocarbon ends directed outwards
(b) hydrocarbon ends directed towards the centre and ionic ends directed outwards
(c) both ionic ends and hydrocarbon ends directed toward the centre
(d) both hydrocarbon ends and ionic ends directed outwards

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. 

Differentiate between:
Detergents and Soaps.

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.

Fill appropriate term in the blank:

Soap is a salt of _______ and sodium hydroxide.

Write an answer to the following question.

How will you check with the help of soap powder whether water is hard?

Write an answer to the following question.

What is meant by 'surface activity'?

Write an answer to the following question.

Name three chemicals responsible for the surface activity of various detergents.

What are the differences between Soap and synthetic detergent?

What are the similarities and differences between Bath soap and soap for washing clothes?

Explain Why Soap cannot be used in hard water.

Explain Why Synthetic detergents are superior to soap.

Explain Why Often coloured spots are formed on clothes during washing.

Soaps were originally made from ______.

The saponification of a fat or oil is done using _____ solution for hot process.

Water, coconut oil, and _______ are necessary for soap preparation.

Arrange the following statements in correct sequence

  1. Pour that solution into an empty matchbox, soap can be obtained after drying.
  2. Take the necessary quantity of water in a jar.
  3. Then add coconut oil drop by drop and stir it well.
  4. Add concentrated sodium hydroxide in the jar and allow it to cool.
  5. Try this soap to wash your hand kerchief.
  6. Cover your work area with old newspaper.

What are the two different types of molecules found in the soap?

TFM in soaps represents ______ content in soap.

The alkaline hydrolysis of fatty acids is termed as ______

We are using ______ to remove strong stains on the clothes.


Used to join components: Adhesives:: Clean the body ______.

How does soap clean clothes?

______ to remove strong strains on the clothes.

______ are substances which can undergo chemical changes to produce certain materials.

What are the similarities between Soap and synthetic detergent.


      Forgot password?
Use app×