Chemistry in Everyday Life

Samacheer Book Back Questions And Answers For Science Standard 6 Term 3 “Chemistry in Everyday Life“

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 Soaps were originally made from _____.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

2. The saponification of a fat or oil is done using _____ solution for hot process.
(a) Potassium hydroxide
(b) Sodium hydroxide
(c) Hydrochloric acid
(d) Sodium chloride

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

4. Phenol is _____.
(a) carbolic acid
(b) acetic acid
(c) benzoic acid
(d) hydrochloric acid

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

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 a farmer’s best friend.
4. _____ fertilizer is eco-friendly.
5. _____ is an example for natural adhesive.

Answers:
1. Propanethial s-oxide
2. Sodium Hydroxide
3. Earthworm
4. Organic
5. Starch

III. True or False. If False, give the correct statement:
1. Concentrated phenol is used as a disinfectant.
2. Gypsum is largely used in medical industries.
3. Plaster of Paris is obtained from heating gypsum.
4. Adhesives are the substances used to separate the components.
5. NPK are the primary nutrients for plants.

Answers:
1. False (Less concentrated phenol is used as a disinfectant)
2. False (Epsom is largely used in medical industry)
3. True
4. False (Adhesives are substances that are used to join two or more components)
5. True

IV. Match the following:
1. Soap             A. C₆H₅OH
2. Cement        B. CaSO₄.2H₂O
3. Fertilizers     C. NaOH
4. Gypsum       D. RCC
5. Phenol         E. NPK

Answers:
1. C
2. D
3. E
4. B
5. A

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 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 handkerchief.
6. Cover your work area with old newspaper.

Answers:
1. Cover your work area with old newspaper.
2. Take the 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 matchbox, soap can be obtained after drying.
6. Try this soap to wash your handkerchief.

VI. Analogy:
1. Urea : Inorganic fertilizer :: Vermi Compost: _____.
2. _____ : Natural Adhesives :: Cello tape : Artificial Adhesives

Answers:
1. Natural Fertilizer
2. Starch

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