Class 10: Chemical used in daily life

 

UNIT 19: CHEMICAL USED IN DAILY LIFE

Multiple Choice Question [1 mark each]

1.    What is the full form of PVC?

a) Polyvinyl chloride  b) Polychloride Vinyl                   c) Polyvico chloride                 d) Polynylon chloride

2.    Which of the following is the example of natural fiber?

a) nylon                     b) polyester                       c) Jute                        d) orlon

3.    Which of the following is an example of soap?

a) Sodium lauryl sulphate                          b) Sodium stearate

c) Sodium Palmitate                                  d) Both b and c

4.    Which one is an example of detergent?

a) Sodium stearate                                    b) Sodium lauryl sulphate

c) Sodium palmitate                                  d) Potassium palmitate

5.    Which substance can be manufactured by using caustic soda and fat?

a) Quartz glass           b) Detergent            c) Ceramics      d) Soap        

6.    Which of the following cannot be used to make compost fertilizer?

a) Banana peel           b) vegetable peel     c) Fine plastic sheets    d) Egg’s shell

7.    Which one of the following is organochlorine insecticide?

a) Malathion              b) Parathion            c) BHC            d) Borax

8.    Which of the following is a traditional food preservative?

a) turmeric                 b) benzoates            c) antioxidants             d) BHA        

9.    Why is vitamin C added to canned food?

a) It kills bacteria                                      b) To supply vitamins to people

10. c) It makes food tastey                                       d) It prevents oxidation

Which one is not a chemical insecticide?

a) triple super phosphate       b) dieldrin     c) BHC            d) DDT

11. What is Sodium benzoate sorbate?

a) Soap                      b) food preservative c) detergent      d) insecticide

12. a

Answers: 1(a), 2(c), 3(d), 4(b), 5(d), 6(c), 7(c), 8(a), 9(d), 10(a)

Very Short Answer Question [1 mark each]

1.     What is food preservative?

Food preservative is a chemical substance that is put into food products to prevent them from decaying.

2.     Write two examples of chemical food preservative.

Two examples of chemical food preservative is sodium benzonate sorbate and Butylated hydroxianisole (BHA).

3.     Give two examples of induced ripening food preservative.

Two examples of induced ripening food preservatives are Calcium carbide and Ethylene gas.

4.     Write any one property of plastic.

One property of plastic is that it is non-biodegradable.

5.     What is a soap?

Soap is the sodium salt of long chain of fatty acid having cleansing property in water.

6.     What is detergent?

Detergent is a long chain of benzene sulphonic acid which is mostly non-biodegradable having high cleansing property.

7.     What are insecticides?

Insecticides are the chemical substances which are used to kill or keep away insects.

8.     What are pesticides?

Pesticides are the chemical substances which are used to kill or chase insects, rodents, termites, fungi, etc.

9.     Write any one use of pesticide.

Pesticides are used to kill or keep away the pests and insects.

10.  Write any one characteristic of dumping site.

One characteristic of dumping site is that the dumping site should be far away from the residential area.

11.  What is chemical pollution?

The pollution of soil, water and air due to the excessive use of chemical substances is called chemical pollution.

12.  Write any one cause of chemical pollution.

One cause of chemical pollution is excessive use of insecticides and chemical fertilizers.

13.  Suggest any one method to reduce the effect of improper solid waste disposal.

One method to reduce the effect of improper solid waste disposal is to segregate the solid wastes and conversion of biodegradable solid wastes into manure.

14.  What are biodegradable wastes?

The solid wastes that are decomposed by microorganisms are called biodegradable wastes.

15.  What is the function of fertilizer?

Fertilizers contain nutrients for the plants and they help in increasing the crop productivity.

16.  Give two examples of traditional use of food preservatives.

Two examples of traditional use of food preservatives are salt and turmeric.

17.  What are antioxidants?

Antioxidants are the chemical substances that are mixed in the food to prevent oxidation are called antioxidants.

18.  Write the names of any two antioxidants.

Colourful fruits and vegetables are the examples of antioxidant.

19.  Which food preservative increase the chance of blood cancer?

Food preservative Benzoates increases the chance of blood cancer.

20.  Write an example of natural hair cleaning agent.

One example of natural hair cleaning agent is Shikakai.

21.  Which chemical is used to artificially ripen fruits?

Calcium carbide is used to artificially ripen fruits.

22.  What is the full form of DDT?

The full form of DDT is Dichloro Diphenyl Trichloroethane

23.  What is the BHC stand for?

BHC stands for Benzene Hexachloride.

24.  Name the raw material used for the preparation of detergent.

Petrochemical is the raw material used for the preparation of detergent. 

25.  What is sodium salt of benzene sulphonic acid called?

Salt of sodium benzene sulphonic acid is called detergent.

26.  Write one health problem seen due to excessive use of detergent.

Contact dermatitis characterized by red itchy rashes are seen on the skin due to the excessive use of detergents.

27.   

Short Answer Questions [2 marks each]

1.     Why is soap not good to wash clothes in hard water?

Soaps are not suitable for washing clothes with hard water because Soap reacts with the calcium and magnesium ions present in hard water to form insoluble precipitate called scum. This results in the wastage of soap instead of cleaning.

2.     Why are detergents called soapless soap?

Detergents are called soapless soap because they have the cleansing properties similar to the soaps but they are different from soap in the chemical composition. Soap contains sodium or potassium salt of fatty acid while detergents are made from petroleum product.

3.     Write any two advantages of adding food preservative in food.

Two advantages of adding food preservatives in food are:

a)     It prevents the food from being decaying.

b)    It maintain the flavor of the food.

4.     “Extra colour and preservatives in food products should be avoided.” Give suitable reasons.

Extra colour and preservative in food products may harm to us. The reasons to avoid them are as follows:

a)     They may cause hyperactivity in young children.

b)    They may cause weakness to the heart tissue which may lead heart problem in old age.

c)     Food preservatives like BHA (Butylated Hydroxy Anisole) used in potatoes, meat and baked goods and BHT (Butylated Hydroxy Toluene) used in cereals and fats may cause cancer.

d)    Preservatives and extra colours used in processed foods can cause obesity in some people as they contain fatty acids.

e)     They may lead to breathing problems such as asthama, bronchitis.

5.     Washermen prefer to use detergents but ecologists suggest using soap. Why?

Detergents have high cleansing property than that of the soaps and they are active even in hard water while soaps do not. So, Washermen prefer to use detergent. But ecologists suggest using soap since detergent are non-biodegradable and they effect the ecosystem of soil and water. In contrary, soaps are biodegradable and does not harm the ecosystem.  

6.     Traditionally, Nepalese people are using spices, oils, and hot chilies to preserve food. Give reason.

Spices, oils and hot chilies have anti-microbial properties. They reduce the risk of food borne infection, narrow the chances of microbial spoilage and preserve the characteristics and nutritional value of the food. So, traditionally, Nepalese people are using spices, oils and hot chilies to preserve food.

7.     Wooden ash can be used to wash clothes. Why?

Wood ash can be used to wash clothes because it contains potassium carbonate, which is a natural alkaline cleaner. Alkaline cleaners work by breaking down the bonds between dirt and fabric fibers, which helps to loosen and remove the dirt. Potassium carbonate is also effective at removing grease and stains.

8.     Write the differences between synthetic food preservatives and traditional food preservatives.

The differences between synthetic food preservatives and traditional food preservatives are as follows:

SN	Traditional food preservative	SN	Synthetic food preservatives
1	They are derived from the plant sources.	1	They are obtained by the chemical reaction.
2	Their use is generally safe.	2	Excessive consumption may lead to health risk.
3	They are not very effective to prevent spoilage than synthetic preservatives.	3.	They are more effective to prevent spoilage than traditional food preservatives.
4.	Examples : chilies, oil, lemon, sugar syrup, salt, vinegar, spices, etc.	4	Examples: sodium benzoate, potassium sorbate, and sodium nitrate.

 

9.     Chlorine is added to sewages, why?

10.  Calcium carbide is banned by the government of Nepal. Why?

11.  Lemon juice is added to water for washing dishes and cleaning tiles.Why?

12.   

Long Answer Questions [4 marks each]

1.     Write down the importance of food preservatives.

2.     Nirdesh has grown a lot of mushroom. He has to preserve the mushroom for long time. Suggest the ways he could preserve mushroom.

Nirdesh can preserve mushroom for long time using the following methods.

Nirdesh can prepare a pickling solution by combining vinegar, water, salt, sugar, and spices. He should boil the solution moderately and add the mushrooms. He should let the mixture for a few minutes until slightly tender. Then he should transfer the mushrooms along with the pickling liquid into sterilized jars, ensuring they are fully submerged. He should seal the jars and store them in a cool, dark place.

Another way by which he should preserve is by Salt curing:

In this method, he Salt curing involves coating the mushrooms in salt, which draws out moisture and inhibits bacterial growth. Nirdesh should clean and slice the mushrooms and fully cover them with salt. He shouldstore the container in the refrigerator or a cool area for a few weeks, regularly draining off any accumulated liquid. Once cured, he should rinse the mushrooms to remove excess salt and store them in an airtight container.

3.     What are the functions of antioxidants? How does it work?

Antioxidant are the chemical substance that are mixed in food stuffs to prevent them from being oxidized. The following are the functions of antioxidants.

a)     They can help to prevent oxidation, which can lead to spoilage.

b)    Antioxidants can help to extend the shelf life of food by preventing it from spoiling. This is important for food manufacturers, as it allows them to sell their products for longer periods of time.

c)     They help to maintain the flavor and color of food. This is important for consumers, as they want their food to taste and look good.

Antioxidants work to preserve food by preventing oxidation. Oxidation is a chemical reaction that occurs when oxygen combines with other molecules. In food, oxidation can cause the food to become rotten, discolored, and lose its flavor. Antioxidants can help to prevent oxidation by reacting with the oxygen molecules before they can damage the food.

4.     Make a list of poisonous pesticides used in agriculture. How do they help us? Enlist their harmful effects.

The list of poisonous insecticides used in agriculture are classified on the following basis:

a)     Biodegradable and non biodegradable: Biodegradable pesticides usually in agriculture are malathion, dimethoate, jhol-mol and non-biodegradable insecticides are DDT, BHC, etc

b)    Targeted organism: insecticides, herbicides, fungicides, rodenticides, miticides, bactericides,

c)     Mode of action: Contact pesticides, systemic pesticides, stomach pesticides, fumicides.

They help us in the following ways:

a)     They kill insects which may reduce the crop productivity within a short period of time enhancing the crop production.

b)    Different kinds of unnecessary herb that reduces the crop productivity can be killed or destroyed by using herbicides.

c)     They keep away the rodents such as rats, rabbits, squirrels, etc.

d)    Plants are also affected by different kinds of bacterial and fungal diseases. Bactericides and fungicides help in controlling fungal and bacterial infection.

The harmful effects of pesticides/insecticides are listed below:

a)     Most of the pesticides are non-biodegradable. So they cause air, soil and water pollution.

b)    Some insecticides, which are used in fruits and crops, leave harmful deposits on them.

c)     Pesticides kills not only harmful insects but also some useful ones.

d)    Powdered insecticides like DDT harm human being, birds, animals and plants.

5.     Enlist the pesticides based on target organisms. Describe each of them.

The following are the lists and description of pesticides based on target organisms:

a)     Insecticides: These pesticides are used to kill insects. Example: Malathion, Cypremethrin, etc.

b)    Rodenticides: These pesticides are used to kill rodents like rat, mice, porcupine, squirrels, hares, etc. Its examples are Phosphide, Bromadiolone, etc.

c)     Fungicides: These are the pesticides used to control the fungal infection in plants. Examples of it are Dimethoform, Carbendazim, etc.

d)    Herbicides: These are the pesticides used to control the unnecessary herbs that affect the growth and development of crops and vegetables. Its examples are: Trifularin, Butachlor, etc.

e)     Miticides: These pesticides are used to control or kill the mites or ticks that damage the plants. Examples are Azobenzene, Dicofol, etc.

f)     Bactericides: Bactericides are the pesticides that are used to control bacteria which causes diseases in plants. Examples of it are streptomycin, nitrofurantoin, etc.

6.    Krischal has planted vegetables but his vegetable plants were destroyed by insects. Agricultural specialist suggest him to use Malathion insecticide. What precautions should he take while using Malathion insecticide?

Krischal has to take following precaution while spraying and using Malathion insecticide.

a)     He should use gloves, apron, boots and gas mask while spraying insecticide.

b)    He should not eat or drink anything while using insecticide.

c)    He should measure the ratio of quantity of insecticide water carefully.

d)    He should use chemical kits to reduce splash and spills while using insecticide.

e)    He should make sure that the insecticide should be out of the reach of children and animals.

7.     How do the use of chemical insecticides and chemical fertilizers harm our health?

Chemical insecticides and chemical fertilizer are harmful for us in the following ways:

a)     Cause cancer: Some pesticides have been linked to an increased risk of cancer.

b)    Damage the nervous system: Pesticides can damage the nervous system, leading to symptoms such as headache, dizziness, nausea, vomiting, muscle weakness, and seizures.

c)     Interfere with the endocrine system: Pesticides can interfere with the endocrine system, which can lead to a variety of health problems, including reproductive problems, birth defects, and developmental delays.

d)    Damage the liver and kidneys: Pesticides can damage the liver and kidneys, due to which a variety of health problems, including liver disease, kidney disease, and kidney failure may occur.

e)     Reduce the immunity system: Chemical insecticides and fertilizers can reduce the body's ability to fight against disease, making people more susceptible to infections.

f)     Cause birth defects: Excessive accumulation of chemical fertilizers and insecticides in the body can cause birth defects, especially if a woman is exposed to them during pregnancy.

8.    Look at the picture shown alongside and answer the questions that follows:

a)    What does the picture show?

The picture shows water pollution due to the discharge of chemicals into water i.e. chemical pollution.

b)    List any two causes of such Pollution.

Two causes of chemical pollution are:

a)    Discharge of industrial wastes directly into the water sources.

b)    Discharge of metallic cans, glasses and plastics wastes into the sources of water.

c)    Mention any two method to reduce the pollution shown in the picture.

Chemical pollution can be reduced by:

a)    Controlling population growth.

b)    Production and use of non-biodegradable substances should be minimized.

d)    Write any two effects on the health of human by such pollution.

Chemical pollution may cause adverse effects on human health. Two effects of chemical pollution are as follows:

a)    Chemical pollutants remain in our body for long time and may interfere with the genes of human body leading to cancer.

b)    Metallic wastes such as mercury, lead, arsenic may interfere with the brain and can cause respiratory problems.