UNIT 19

CHEMICALS USED IN DAILY LIFE

Exercise

1. Choose the correct option for the following questions:

a. Why is detergent called a soapless soap?

i. It does not give lather with hard water as a soap.
ii. It has the same chemical composition as of soap.
iii. It has cleaning properties like soap and it can be used with hard water.
iv. It has cleaning properties like soap but its chemical nature is different.

b. Identify the group of insecticides?

i. Potassium chloride, aldrin, benzene hexa chloride
ii. DDT. sodium chloride, aldrin
iii. Dieldrin, DDT, methoxychloride
iv. Potassium chloride, aldrin. malathion

c. In which group does sodium stearate lie?

i. Soap
ii. Detergent
iii. Insecticide
iv. Food preservative

d. What is the main use of detergents?

i. To clean hands and foot
ii. To take bath.
iii. To wash clothes
iv. To clean toilet

e. Which of the following compounds is used to ripen fruits?

i. Calcium carbide
ii. Calcium carbonate
iii. Sodium sulphate
iv. Sodium carbonate

2. Write differences between:

a. Chemical pesticides and biological pesticides Pesticides Comparison

Chemical Pesticides Biological Pesticides

1. Chemical pesticides are synthetic chemicals used to control pests and diseases in crops. 1. Biological pesticides, also known as biopesticides, are derived from natural organisms like bacteria, fungi, and plants.

2. They are often persistent in the environment and can cause pollution and harm to non-target species. 2. Biological pesticides are generally safer for the environment and non-target organisms, as they target specific pests.

3. Chemical pesticides can lead to the development of pest resistance over time. 3. Biological pesticides are less likely to lead to resistance, as they often involve natural mechanisms like pathogens or predators.

4. Chemical pesticides tend to work faster but may require more frequent applications. 4. Biological pesticides may have slower action but often have longer-lasting effects on pests.

5. Example: Insecticides like DDT, Herbicides like Glyphosate. 5. Example: Bacillus thuringiensis (Bt), Neem oil, or predatory insects like ladybugs.

Chemical Pesticides	Biological Pesticides
1. Chemical pesticides are synthetic chemicals used to control pests and diseases in crops.	1. Biological pesticides, also known as biopesticides, are derived from natural organisms like bacteria, fungi, and plants.
2. They are often persistent in the environment and can cause pollution and harm to non-target species.	2. Biological pesticides are generally safer for the environment and non-target organisms, as they target specific pests.
3. Chemical pesticides can lead to the development of pest resistance over time.	3. Biological pesticides are less likely to lead to resistance, as they often involve natural mechanisms like pathogens or predators.
4. Chemical pesticides tend to work faster but may require more frequent applications.	4. Biological pesticides may have slower action but often have longer-lasting effects on pests.
5. Example: Insecticides like DDT, Herbicides like Glyphosate.	5. Example: Bacillus thuringiensis (Bt), Neem oil, or predatory insects like ladybugs.

b. Chemical food preservative and organic food preservative Food Preservatives Comparison

Chemical Food Preservatives Organic Food Preservatives

1. Chemical preservatives are synthetic chemicals used to extend the shelf life of food. 1. Organic preservatives are derived from natural sources such as plants, herbs, or animal products.

2. They often have side effects, such as allergic reactions or toxicity in large quantities. 2. Organic preservatives are generally considered safer for human consumption with fewer side effects.

3. Common chemical preservatives include artificial additives like sodium benzoate, sulfur dioxide, and BHA (Butylated HydroxyToluene). 3. Organic preservatives include natural substances like vinegar, salt, sugar, and citric acid.

4. They are often used to prevent spoilage, discoloration, and to preserve flavor. 4. Organic preservatives typically maintain the natural flavor and nutritional value of the food while slowing microbial growth.

5. Chemical preservatives are commonly found in processed, packaged, and convenience foods. 5. Organic preservatives are more commonly used in home-made, organic, and minimally processed foods.

Chemical Food Preservatives	Organic Food Preservatives
1. Chemical preservatives are synthetic chemicals used to extend the shelf life of food.	1. Organic preservatives are derived from natural sources such as plants, herbs, or animal products.
2. They often have side effects, such as allergic reactions or toxicity in large quantities.	2. Organic preservatives are generally considered safer for human consumption with fewer side effects.
3. Common chemical preservatives include artificial additives like sodium benzoate, sulfur dioxide, and BHA (Butylated HydroxyToluene).	3. Organic preservatives include natural substances like vinegar, salt, sugar, and citric acid.
4. They are often used to prevent spoilage, discoloration, and to preserve flavor.	4. Organic preservatives typically maintain the natural flavor and nutritional value of the food while slowing microbial growth.
5. Chemical preservatives are commonly found in processed, packaged, and convenience foods.	5. Organic preservatives are more commonly used in home-made, organic, and minimally processed foods.

C. Soap and detergent [SEE 2080 Bagmati] Soap vs Detergent

Soap Detergent

1. Soap is made from natural fats or oils combined with an alkali (like sodium hydroxide). 1. Detergents are synthetic cleansing agents made from petrochemicals or other synthetic substances.

2. Soap is typically biodegradable and less harmful to the environment. 2. Detergents may contain synthetic chemicals that are not biodegradable and can harm the environment.

3. Soap works best in soft water but can form scum in hard water, reducing its effectiveness. 3. Detergents are effective in both soft and hard water, as they don't form scum.

4. Soap has a more limited range of uses, typically used for personal hygiene and cleaning of fabrics. 4. Detergents have a wider range of uses, including household cleaning, dishwashing, and laundry.

5. Example: Bar soap, Liquid soap, Castile soap. 5. Example: Laundry detergent, Dishwashing liquid, All-purpose cleaners.

Soap	Detergent
1. Soap is made from natural fats or oils combined with an alkali (like sodium hydroxide).	1. Detergents are synthetic cleansing agents made from petrochemicals or other synthetic substances.
2. Soap is typically biodegradable and less harmful to the environment.	2. Detergents may contain synthetic chemicals that are not biodegradable and can harm the environment.
3. Soap works best in soft water but can form scum in hard water, reducing its effectiveness.	3. Detergents are effective in both soft and hard water, as they don't form scum.
4. Soap has a more limited range of uses, typically used for personal hygiene and cleaning of fabrics.	4. Detergents have a wider range of uses, including household cleaning, dishwashing, and laundry.
5. Example: Bar soap, Liquid soap, Castile soap.	5. Example: Laundry detergent, Dishwashing liquid, All-purpose cleaners.

3. Give reason

a. Use of DDT powder causes imbalance in the ecosystem.

→ The use of DDT powder causes environmental pollution by disrupting ecosystems, killing both harmful and beneficial insects. It contaminates soil and water, harming aquatic animals and causing reproductive issues in fish and birds. DDT accumulates in the food chain and can lead to respiratory diseases in living organisms. Its persistence in soil further degrades soil quality and harms biodiversity.

b. The use of chemical pesticides should be decreased.

→ The use of chemical pesticides should be decreased because their excessive and unscientific use has caused serious health issues like cancer. Additionally, unsafe handling of chemical pesticides leads to injuries as well as pollution of surface and underground water highlighting the need for safer practices and reduced dependence on harmful chemicals.

C. Salt is used in the process of making soap.

→ Salt is used in the process of making soap to precipitate soap out of the solution making it solid.

d. Pickles can be preserved for a long time.

→ Most of the pickles uses oil and salt which acts as a preservative and prevents pickle from decaying by checking the growth of bacteria, yeast, mold etc.

4. Answer the following questions:

a. Write the full forms of DDT and BHC.

→ DDT- Dichlorodiphenyltrichloroethane

BHC- Benzene hexachloride

b. What do you mean by food preservatives? Why are they used?

→ The substances used to protect food from decaying are called food preservatives. They are used to prevent food from decaying for a long time.

C. What chemicals are used as food preservatives?

→ The chemicals like sodium benzoate sorbate, Sulphur dioxide, nitrates and nitrites, butylated hydroxyanisole (BHA), butylated hydroxytoulene (BHT), calcium propionate, sodium metabisulfite are used as food preservatives.

d. What are the natural methods used to preserve the nutrients of food?

→ The natural methods used to preserve food are as follows:

· Sugaring

· Salting

· Pickling

· Spices and oils

· Broiling

· Freezing

· Canning

· Drying

· Refrigeration

· Boiling

e. What do you mean by natural food preservatives? Why are they good in comparison to the chemical food preservatives? Analyze it.

→ The substances which can directly be obtained from the natural organic sources and can be used to protect food from decaying are called natural food preservatives.

They are good in comparison to chemical food preservatives because they have fewer side effects on health of human and do not degrade the environment.

f. How can fruits be ripened artificially? Write methods and processes for it.

→ Fruits can be ripened artificially by using chemicals like calcium carbide, ethylene gas, ethephon etc.

- METHOD & PROCESSES:

· Calcium Carbide: It should be applied in small quantities on the surface of fruits in closed environment. Doing this will release acetylene gas which helps in ripening process.

· Ethylene gas: Ethylene gas is released in a controlled environment, either through the use of ethylene generators or by storing fruits in rooms where the gas concentration is kept at a specific level.

· Ethephon: Ethephon is typically applied as a spray or dip to fruits before they are harvested or in the early stages of ripening.

g. What precautions should be taken while using chemical pesticides?

→ Following precautions should be taken while using chemical pesticides:

· The import, production, business and use of chemical pesticides should be done in accordance with the law.

· It should be bought only in the prescription or suggestion of expert JTA.

· The vessel in which the chemical pesticides are stored should be named properly.

· Chemical pesticides should be stored in a sealed and non-leaking container.

· Hands should be washed properly with soap and water after using chemical pesticides.

· The crops shouldn’t be sold or used immediately after using chemical pesticides.

h. Make a list of chemicals used for cleaning purposes in your house and locality? Write the effects of these substances in the environment.

→ Following are the list of chemicals used for cleaning purpose in our home and locality:

· Soap

· Detergent

· Phenyl

· Bleaching powder etc.

The effects of these chemicals in environment are as follows:

· Soaps contain phosphates and surfactants, which can contribute to water pollution when they enter water bodies through wastewater.

· Detergents can contribute to water pollution by encouraging the excessive growth of algae.

· Phenol and chlorophenol containing phenyl can have several effects on the environment, including water pollution, soil contamination, air pollution, and toxicity to wildlife.

· Bleaching powder interact with organic impurities to make it carcinogenic.

i. Explain the soap making process.

→ Process of making a soap:

Materials required: animal fat or vegetable oil, NaOH solution, common salt, beaker, funnel, filter paper, source of heat

Procedure:

Fig: Soap making process

· Take about 40 ml of vegetable oil in a beaker.

· Make about 50 ml mixture of NaOH by dissolving 15 grams of NaOH in 50 ml water.

· Mix both of them and heat the mixture for some time which gives a thick paste. Add a little soda and common salt which separates soap from the mixture.

· Filter the mixture by using filter paper. The residue left on filter paper is soap.

· Pour the soap in a desired shape vessel. Keep the soap untouched for a day.

j. What is detergent? Write its two examples. What effects are seen on the human health and environment due to the use of detergent? Present your argument.

→ Detergent can be defined as a substance used to clean clothes.

The use of detergent causes problems like skin irritation or skin burn in human while it may cause soil and water pollution in the environment.

k. There has been an excessive use of chemical pesticides in Hari's village due to which complex problems have been observed in the health of people and the environment. What may be the alternatives to solve these problems? Give some suggestions.

→ Following alternatives can be used to resolve problems of health and environment due to chemical pesticides:

· Only those pesticides should be imported, produced, traded or used which are permitted by ‘Pesticides management act 2076’.

· Pesticides should be kept out of reach of children.

· Only less harmful but effective pesticides should be used.

· We should endorse the use of organic fertilizers and biological pest control methods.

l. What do you mean by chemical pollution? What are its effects? Write practical ways to minimize it.

→ If a chemical substance degrades the natural quality of the environment, offend the senses of sight, taste, or smell, or cause a health hazard, then such pollution is called chemical pollution.

Effects of chemical pollutions are as follows:

· It creates imbalance in the ecosystem.

· It causes negative impacts on aquatic and terrestrial animals.

· It affects reproductive system in organisms.

· It causes different respiratory diseases.

· It degrades the quality of a soil.

Following measures can be adopted to minimize it

· Organic or compost fertilizers should be used instead of chemical fertilizers.

· The waste water after use of soap and detergent should not be directly mixed to water sources or agricultural land.

· Reduce, Recycle or reuse automotive liquids, and donate items like paint and chemicals to those who can make use of them.

· We should buy and use only what we need.

m. Write about the pollution caused by industrial products like cement, glass, ceramics, plastic, fiber, chemical fertilizers, soap, detergent,etc. in your locality. Write its causes and suggest proper ways for management.

→ The industrial products like cement, glass, ceramics, plastic, fiber, chemical fertilizers, soap, detergent etc has degraded the quality of different components of the environment like air, water, soil etc. which causes imbalance in ecosystem.

The cause of this pollution are as follows:

· Overuse of chemical pesticides,

· Dependence on chemical fertilizers

· Plastic and wastes from home and kitchen

· Synthetic cleansers

· Colors used in food etc.

Proper ways of managing it:

· Glass, ceramics, plastics, fibers etc shouldn’t be thrown haphazardly and should be managed in proper places.

· Cement sacs should be tied and covered properly to prevent dust blow.

· Organic and compost fertilizers should be used.

· Chemical fertilizers and pesticides should be used only as directed by agricultural expert.

Questions Asked In SEE

1. We should use and store pesticides carefully. Write two reason behind this. [SEE 2080 Koshi]

→ We should use and store pesticides carefully due to following reasons:

a) to protect beneficial insects, wildlife, human and to prevent environmental harm.

b) to prevent children from its accidental exposure and spills.

2. Pollutants of a city are shown in the given diagram. [SEE 2080 Koshi]

(i) which pollutants of them is non biodegradable?

(ii) How can we manage such pollutants?

→ Among them - plastics, glass, ceramics and fibers are non bio degradable. We can manage such pollutants by following these methods:

Glass, ceramics, plastics, fibers etc shouldn’t be thrown haphazardly and should be managed in proper places.
Cement sacs should be tied and covered properly to prevent dust blow.

3. Write any two advantages of use of food preservatives. [SEE 2080 Gandaki]

→ The two advantages of use of food preservatives are as follows:

They make food more resistant to microorganism growth.
They help to reduce food waste thus decreasing production cost.

4. Why is detergent considered as more pollutant than soap? [SEE 2080 Karnali]

→ Detergent is considered more pollutant than soap because detergent is not biodegradable and hence it causes chemical pollution in water and land.

5. Detergent is considered more efficient than soap in laundry, why? [SEE 2080 Lumbini]

→ Detergent is considered more efficient than soap in laundry because it eliminate the laborious rubbing of laundry by hand. Detergents also work well in both hard and soft water, while soap can form scum in hard water thus reducing its effectiveness.

6. A person wants to eat mature mango fruit soon by using artificial ripening method. After some days, the person feels itching in skin, finds rashes in skin, and eyes become red and itching. which chemical could have been used by the person for ripening of mango? What is another chronic effect of excessive use of it? [SEE Grade Increment exam - 2080]

→ The chemical he might have used is Calcium carbide which releases acetylene gas when exposed to moisture triggering ripening of mango.

Excessive use of calcium carbide may cause chronic respiratory diseases like breathing difficulty, coughing etc. It may also cause problems in liver and kidneys.

7. How are the chemicals produced from industries managed? write any two points. [SEE 2080 Bagmati]

→ Chemicals produced from industries are managed in following ways:

By properly tagging and labelling chemical containers.
By managing and reducing chemical wastes.

8. Why is food preservative used? [SEE 2080 Sudurpaschim]

→ Answer is same as in question no 3.

9. Define food preservatives with an example. Write any two points those should be remembered while using food preservatives. [SEE 2080 Madhesh]

→ The substances which can be used to protect food from decaying are called food preservatives. Examples: common salt, sugar, vegetable oil, nitrates, calcium propionate etc.

Following things should always be taken in mind while using food preservatives:

Use preservatives in recommended amounts to avoid health risks.
Store preserved foods properly to maintain their effectiveness and prevent spoilage.

Chemicals Used in Daily Life (Solution of Science, Class X)