Science Class 12 - Chemistry In-Everyday-Life Notes

Chemistry in Everyday Life

Welcome to the chapter on Chemistry in Everyday Life for Class 12. In this chapter, you will learn how chemistry is a part of our daily lives, from medicines and food to cleaning agents and cosmetics. By the end of this chapter, you will understand the role of chemicals in health, hygiene, and industry, and how to use them safely and responsibly.

Introduction

Chemistry is not just a subject in the classroom—it is everywhere around us. The food we eat, the medicines we take, the soaps we use, and even the clothes we wear involve chemistry. Let’s explore how chemicals make our lives better and safer.

Drugs and Medicines

• Analgesics: Painkillers like paracetamol and aspirin.
• Antibiotics: Drugs that kill or stop the growth of bacteria, e.g., penicillin.
• Antiseptics: Chemicals applied to living tissues to prevent infection, e.g., Dettol.
• Disinfectants: Chemicals used on non-living objects to kill microorganisms, e.g., phenol.
• Antacids: Substances that neutralize excess stomach acid, e.g., milk of magnesia.

Chemicals in Food

• Preservatives: Prevent spoilage of food, e.g., sodium benzoate, salt, sugar.
• Artificial Sweeteners: Used by diabetics, e.g., aspartame, saccharin.
• Food Colors and Flavours: Enhance appearance and taste, e.g., tartrazine, vanillin.

Cleansing Agents

• Soaps: Sodium or potassium salts of fatty acids, used for cleaning.
• Synthetic Detergents: Clean in hard water, e.g., sodium lauryl sulphate.
• Toothpaste and Shampoos: Contain mild abrasives and detergents.

Chemicals in Cosmetics

• Perfumes, deodorants, creams, and lotions contain various chemicals for fragrance and skin care.
• Some cosmetics may cause allergies; always check ingredients.

Other Applications

• Polymers: Plastics, nylon, and polyester are used in packaging, clothing, and utensils.
• Fertilizers and Pesticides: Increase crop yield and protect plants.
• Dyes and Paints: Used in textiles, art, and construction.

Safety and Environmental Concerns

• Use chemicals as directed and store them safely.
• Improper use of chemicals can harm health and the environment.
• Prefer eco-friendly and biodegradable products when possible.

Practice Questions

1. What is the difference between an antiseptic and a disinfectant?
2. Name two artificial sweeteners and their uses.
3. Why are synthetic detergents preferred over soaps in hard water?
4. List two chemicals used as food preservatives.
5. What are the environmental concerns related to the use of fertilizers and pesticides?

Challenge Yourself

• Research and write about a chemical used in your home and its safety precautions.
• Find out how biodegradable detergents are different from regular detergents.

Did You Know?

• The first antibiotic, penicillin, was discovered by Alexander Fleming in 1928.
• Some food colors are made from natural sources like beetroot and turmeric.

Glossary

• Antibiotic: A drug that kills or stops the growth of bacteria.
• Preservative: A substance used to prevent food spoilage.
• Detergent: A cleaning agent that works in hard water.
• Polymer: A large molecule made from many smaller units (monomers).

Answers to Practice Questions

1. Antiseptics are used on living tissues; disinfectants are used on non-living objects.
2. Aspartame and saccharin; both are used as sugar substitutes for diabetics.
3. Synthetic detergents do not form scum in hard water, so they clean better.
4. Sodium benzoate and salt (sodium chloride).
5. They can pollute soil and water, harm useful organisms, and cause health problems.

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Chemistry is everywhere! Use chemicals wisely to make life better and safer.