Chemistry in Everyday Life
1. Introduction
Chemistry in Everyday Life deals with the application of chemistry in daily human activities.
It explains how chemical substances improve our quality of life through medicines, food,
cleansing agents, and other useful materials.
2. Drugs and Medicines
A drug is a chemical substance used to diagnose, prevent, or treat diseases.
Medicines are drugs used in correct doses for therapeutic purposes.
3. Classification of Drugs Based on Pharmacological Effect
| Class | Function |
|---|---|
| Analgesics | Relieve pain |
| Antipyretics | Reduce fever |
| Antibiotics | Kill or inhibit bacteria |
| Antiseptics | Prevent infection on living tissues |
| Disinfectants | Kill microorganisms on non-living objects |
4. Analgesics
Analgesics are drugs that reduce or eliminate pain without causing loss of consciousness.
Examples: Aspirin $(\mathrm{C_9H_8O_4})$, Paracetamol $(\mathrm{C_8H_9NO_2})$
Aspirin inhibits the synthesis of prostaglandins responsible for pain and inflammation.
5. Antipyretics
Antipyretics are drugs used to lower body temperature during fever.
Example: Paracetamol $(\mathrm{C_8H_9NO_2})$
6. Antibiotics
Antibiotics are drugs that kill or inhibit the growth of bacteria.
They are ineffective against viral infections.
Examples: Penicillin, Streptomycin, Tetracycline
Overuse of antibiotics can lead to antibiotic resistance.
7. Antiseptics and Disinfectants
Antiseptics are applied to living tissues, while disinfectants are applied to non-living surfaces.
| Antiseptic | Disinfectant |
|---|---|
| Tincture of iodine | Phenol |
| Chlorhexidine | Bleaching powder |
8. Antacids
Antacids are substances that neutralize excess hydrochloric acid in the stomach.
$\mathrm{Mg(OH)_2 + 2HCl \rightarrow MgCl_2 + 2H_2O}$
Common antacids: Magnesium hydroxide, Sodium bicarbonate
9. Tranquilizers
Tranquilizers are drugs that reduce mental stress and anxiety.
Examples: Diazepam, Barbiturates
10. Food Additives
Food additives are chemicals added to food to improve taste, texture, shelf life, and appearance.
Types of Food Additives
| Type | Example |
|---|---|
| Preservatives | Sodium benzoate |
| Sweetening agents | Aspartame |
| Flavouring agents | Vanillin |
11. Artificial Sweetening Agents
Artificial sweeteners provide sweetness without adding calories.
Examples: Saccharin, Aspartame $(\mathrm{C_{14}H_{18}N_2O_5})$
Aspartame is unstable at high temperatures and unsuitable for cooking.
12. Soaps
Soaps are sodium or potassium salts of long-chain fatty acids.
$\mathrm{RCOO^-Na^+}$
Soaps work effectively in soft water.
13. Cleansing Action of Soap
Soap molecules form micelles where the hydrophobic tail traps grease
and hydrophilic head dissolves in water.
14. Detergents
Detergents are cleansing agents that work in both hard and soft water.
Example: Sodium alkyl benzene sulphonate
15. Difference Between Soaps and Detergents
| Soaps | Detergents |
|---|---|
| Ineffective in hard water | Effective in hard water |
| Biodegradable | Some are non-biodegradable |
16. Common Exam Traps
- Antibiotics do not cure viral diseases
- Detergents are not salts of fatty acids
- Antacids neutralize acid, not reduce acid production
17. Final Revision Checklist
You have mastered this chapter if you can:
- Classify drugs correctly
- Write reactions of antacids
- Differentiate soaps and detergents
- Explain cleansing action using micelles
- Identify uses of food additives