29 Apr 2022

Samacheer kalvi 6th Science Term 3 Unit 3 Answers

Samacheer Kalvi 6th Science Term 3 Unit 3 Book Back Question and Answers/Solutions:

Samacheer Kalvi 6th Standard New Science Book Back 1 Mark and 2 Mark Question & Answers PDF uploaded and available below. Class 6 New Syllabus 2021 to 2022 Book Back Question & Answer solutions available for both English and Tamil Medium. Class 6 Science  Book Term 3 Unit 3 Chemistry in Everyday Life Answers/Solutions are provided on this page. 6th Std Science Book is of 1st Term, 2nd Term consists of 7 units and 3rd Term consists of 6 units. All Units/Chapters of Term 1st, 2nd, 3rd Social Book Back One, and Two Mark Solutions are given below.

Check Unit wise and  6th New Science Book Back Question and Answers Guide/Solutions PDF format for Free Download. English, Tamil, Maths, Science, and Social Science Book Back Questions and Answers available in PDF. Check Science Book Back Solutions below. See below for the Samacheer Kalvi 6th Science Term 3  Unit 3 Book Back Answers PDF:




Samacheer Kalvi 6th Science Book Back Chapter 3 Term 3 Answers/Solutions Guide PDF:

Science Subject 1 Mark and 2 Mark Solutions Guide PDF available below. Click the Download option to download the book back 1 Mark & 2 Mark questions and answers. Take the printout and use it for exam purposes.

6th Science – Term 1 Unit 3

Chemistry in Everyday Life

I. Choose the appropriate answer:

1. Soaps were originally made from _______
(a) proteins
(b) animal fats and vegetable oils
(c) chemicals extracted from the soil
(d) foam booster
Answer.
(b) animal fats and vegetable oils

2. The saponification of a fat or oil is done using ……….. solution for hot process.
a. potassium hydroxide
b. sodium hydroxide
c. sodium chloride
d. sodium hydroxide
Answer:
b. sodium hydroxide

3. Gypsum is added to the cement for _______
(a) fast setting
(b) delayed setting
(c) hardening
(d) making paste
Answer:
(b) delayed setting

4. Phenol is ……..
a. carbolic acid
b. acetic acid
c. benzoic acid
d. hydrochloric acid
Answer:
a. carbolic acid

5. Natural adhesives are made from _______
(a) Protein
(b) fat
(c) starch
(d) vitamins
Answer:
(c) starch

II. Fill in the blanks :

  1. _______ gas causes tears in our eyes, while cutting onions.
  2. Water, coconut oil and ________ are necessary for soap preparation.
  3. _______ is called as farmer’s best friend.
  4. _______ fertilizer is ecoffiendly.
  5. _______ is an example for natural adhesive.

Answers:

  1. Propanethial s-oxide
  2. animal fat
  3. Earthworm
  4. Organic
  5. Starch dissolved in water

III. True or False. If False, give the correct statement:

1. Concentrated phenol is used as a disinfectant.
Answer:
False. Low concentrated phenol is used as a disinfectant.

2. Gypsum is largely used in medical industries.
Answer:
False. Gypsum is largely used in cement preparation.

3. Plaster of Paris is obtained from heating gypsum.
Answer:
True.

4. Adhesives are the substances used to separate the components.
Answer:
False. Adhesives are the substances used to join the components.

5. NPK are the primary nutrients for plants.
Answer:
True.

IV. Match the following :

6th science book back questions with answer

Answer:
1 – iii; 2 – iv; 3 – v; 4 – ii; 5 – i





V. Arrange the following statements in correct sequence:

  1. Pour that solution into an empty match box, soap can be obtained after drying.
  2. Take necessary quantity of water in ajar.
  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.

Answers:

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

VI. Analogy :

1. Urea : Inorganic fertilizer;
Vermi compost: _______
Answer:
Organic fertilizer.

2. _______ : Natural adhesives ;
Cello tape : Artifical adhesives.
Answer:
Starch dissolved in water.

VII. Give Very Short Answer:

1. What are the three main constituents of soap?
Answer:
The three main constituents of soap are Lye (Sodium hydroxide), coconut oil and water.

2. What are the two different types of molecules found in the soap?
Answer:

  1. Loving water molecules.
  2. Hating water molecules.

3. Give an example of inorganic fertilizer.
Answer:
The Inorganic fertilizers are Urea, Ammonium sulphate and Super phosphate.

4. Mention any three physical properties of phenol?
Answer:

  1. Weak acid
  2. High volatile
  3. White crystalline powder.

5. Explain the uses of plaster of paris.
Answer:
Uses of plaster of pairs :

  1. In making black board chalks.
  2. In surgery for setting fractured bones.
  3. For making casts for statues and toys etc.
  4. In the construction industry.

6. What are the ingredients of the cement?
Answer:

  1. Limestone
  2. Clay
  3. Gypsum

7. Why gypsum is used in cement production?
Answer:
Gypsum is added to control the setting of cement.

VIII. Give Short Answer:

1. Why earthworm is called a farmer’s friend?
Answer:
Earthworms take organic wastes as food and produce compost castings. So earthworms are known as Farmers’ Friends because of the multitude of services they provide to improve soil health and consequently plant health.

2. Explain the process of manufacturing cement.
Answer:
The cement is manufactured by crushing of naturally occurring minerals such as lime stone, clay and gypsum through a milling process.

3. What are uses of Gypsum?
Answer:
Uses of Gypsum :

  1. It is used as fertilizers.
  2. It is used in the process of making cement.
  3. It is used in the process of making Plaster of Paris.

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