Questions Answers

Evalution

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 Soaps were originally made from ___________ .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. Hydrochloric acid

d. Sodium chloride

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. Propanethial s-oxide gas causes tears in our eyes while cutting onions.

2. Water, coconut oil and sodium hydroxide are necessary for soap preparation.

3. Earthworm is called as farmer’s best friend.

4. Organic fertilizer is ecofriendly.

5. Starch is an example for natural adhesive.

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

1. Concentrated phenol is used as a disinfectant. (False)

Diluted phenol is used as a disinfectant.

2. Gypsum is largely used in medical industries. (False)

Epsom is largely used in medical industries.

3. Plaster of Paris is obtained from heating gypsum. (True)

4. Adhesives are the substances used to separate the components. (False)

Adhesives are the substances used to stick to the components.

5. NPK are the primary nutrients for plants. (True)

IV. Match the following

1. Soap - C₆H₅ OH

2. Cement - CaSO₄.2H₂O

3. Fertilizers - NaOH

4. Gypsum - RCC

5. Phenol – NPK

Answer:

1. Soap - NaOH

2. Cement- RCC

3. Fertilizers - NPK

4. Gypsum- CaSO₄.2H₂O

5. Phenol- C₆H₅OH

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 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.

Answer:

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: ____________.

Urea : Inorganic fertilizer:Vermi compost: Organic fertilizer.

2. _____________: Natural adhesives: Cello tape: Artificial adhesives.

Starch: Natural adhesives :: Cello tape : Artificial adhesives.

VII. Give very short answer

1. What are the three main constituents of soap?

 (i) Sodium hydroxide

 (ii) Coconut oil

 (iii) Water

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

(i) Water loving molecules

(ii) Water hating molecules.

3. Give an example for inorganic fertilizer.

Ammonia, Super phosphate, Ammonium sulphate, Potassium nitrate.

4. Mention any three physical properties of phenol.

(i) It is a white crystalline powder.

(ii) It is easily volatile.

(iii) When mixed with water it becomes a colourless solution but it turns red in presence of dust. 

5. Explain the uses of plaster of paris.

It is used

1. In making blackboard chalks

2. In surgery for setting fractured bones.

3. For making casts for statues and toys.

4. In construction industry.

6. What are the ingredients of the cement?

Naturally occurring minerals like lime, clay and gypsum are the ingredients of cement.

7. Why gypsum is used in cement production?

Gypsum is added to control the setting of cement.

VIII. Give short answer

1. Why earthworm is called as farmer’s friend?

Earthworms take organic wastes as food and produce compost castings. By burrowing into the soil they loosen the earth and enable aeration of the soil. 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.

Cement is manufactured by crushing of naturally occurring minerals such as lime, clay and gypsum through milling process.

Cement becomes hardened when it is mixed with water. Gypsum plays a very important role in controlling the rate of hardening of the cement. During the cement manufacturing process, a small amount of gypsum is added at the final grinding process. Gypsum is added to control the "setting of cement". 

3. What are uses of Gypsum?

Gypsum is

❖ used as fertilizers.

❖ used in the process of making cement.

❖ used in the process of making plaster of paris.

IX. Answer in detail

1. How are detergents manufactured?

Calculated amount of concentrated sodium hydroxide is added to the required amount of water. It is allowed to cool. The required quantity of coconut oil is added to it drop by drop. The solution is stirred well. By stirring continuously the solution is turned into a colloidal state. It is cast in moulds and thus detergent soap is prepared.

X. Questions based on Higher Order Thinking Skills

1. Ravi is a farmer; he rears many cattle in his farm. His field has many bio wastes. Advise Ravi how to change this bio waste to compost by using vermi -composting techniques. Explain the benefits of vermi castings.

Make pits in the land and fill half of the pits with cattle waste, leaves, husk, straw and compost as layers. Some soil or sand must be sprinkled on it for the easy mobility of earthworms. Water should be sprinkled on it to make it moist. Then earthworms should be let into the pits. In order to protect the pits from sunlight they should be covered with coconut leaves or jute. After sixty days the contents of the pit will be changed into organic manure rich in nutrients. This vermicompost is an excellent organic manure for plants.

1. Vermicompost is nutritious and it makes the soil fertile.

2. It improves the quality of the soil, shape, aeration and its ability to retain water.

3. It prevents soil erosion and improves decomposition of organic materials in the soil.

4. Vermi compost contains advantageous micro organisms and it is free from disease causing germs. It is also non-toxic. 

XI. Project

* Take 100 ml of hot water in a glass jar.

* Add 50 gram of maida in the hot water and stir it well.

* A paste like substances are formed. Add a small quantity of copper sulphate for a long use.

* Now you test this paste by binding your damaged book.