Samacheer Kalvi 6th Science Term 3 Unit 3 Book Back Questions and Answers:

Samacheer Kalvi 6th Standard Science Book Back 1 Mark and 2 Mark Question & Answers uploaded online and available PDF for free download. Class 6th New Syllabus Science Term 3 book back question & answer solutions guide available below for English Medium. Class sixth Std Science English Medium Term 3 Unit 3 Chemistry in Everyday life book back answers given below. Students looking for class 6th Term III Unit 3 Questions and Answers can check below.

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TN State Board Class 6th Science Subject Term 3 Unit 3 one mark and two mark solutions guide PDF available below.

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 Soaps were originally made from _______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 substances used to separate the components.
Answer:
False. Adhesives are substances used to join the components.

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

IV. Match the following :

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

V. Arrange the following statements in the correct sequence:

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

Answers:

1. Cover your work area with old newspapers.
2. Take a necessary quantity of water in a jar.
3. Add concentrated sodium hydroxide to 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 matchbox, soap can be obtained after drying.
6. Try this soap to wash your handkerchief.

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 a 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 a 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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