CBSE Class 12th Chemistry Notes: Chemistry in Everyday LifeGurmeet Kaur
This article provides you the revision notes on Class 12 Chemistry: Chapter- Chemistry in Everyday Life, to give you a quick glance of the chapter. In this article you will learn about the various types of drugs, food preservatives and cleansing agents. These quick notes are prepared strictly according to the latest CBSE syllabus for Class 12th Chemistry.
The main topics covered in this part are:
• Drugs and Medicines
• Some Important Classes of Drugs
• Food Preservatives
• Cleansing Agents
The key notes of the chapter are as follows:
Drugs and Medicines
Drug, also called medicine, is a chemical substance used to cure, prevent, or diagnose a disease
Use of chemical substances for the treatment of a disease is termed as chemotherapy.
Some Important Classes of Drugs
• Tranquilizers are the chemicals used to relieve stress, mental tension, anxiety. These form a major component of the sleeping pills. Most of these drugs are derivatives of barbituric acid. Examples: Luminal, equanil, iproniazid, barbiturate.
• Analgesics: These are the drugs used to reduce or abolish pain without causing the loss of consciousness, paralysis and some other disturbances.
For example- Asprin, Analgin, Paracitamol.
These are of two types:
(i) Narcotics: These drugs relieve pain but also produce sleep or drowsiness. These are habit forming drugs and are also termed as addictive drugs.
For example: Morphine, codeine, heroin.
(ii) Non-narcotics: These are non-habit forming drugs also named as non-addictive drugs. These are used to reduce mild to moderate pains such as headache, toothache, muscle and joint pain, etc. These drugs do not produce drowsiness.
For example: Asprin, paracitamol.
• Antiseptics: These are the chemicals which are used to kill or to prevent the growth of microorganisms without affecting the living human tissues.
For example: Dettol (chloroxylenol + terpeneol), Bithional, tincture of iodine, iodoform.
• Disinfectants: These are the antimicrobial agents that are applied to the surface of non-living objects to destroy microorganisms that are living on the objects.
For example: 0.2% solution of phenol act as a disinfectant. KMnO4, Cl2 are also used as disinfectant.
• Antibiotics: These are the chemical substances produces from microorganisms and are used to kill or inhibit the growth of microorganisms.
For example- Penicillin, Tetracycline, Ampicillin.
• Antipyretic: They are used to lower the body temperature in case of high fever.
For example: Aspirin, paracetamol, phenacetin.
• Antifertility Drugs: These drugs are used to control birth and population. These drugs are esentially a mixture of synthetic estrogen and progesterons derivatives which are more potent than the natural hormones.
For example: Mala D, Norethindrone, Novestrol.
• Antacid: The chemical substances which neutralize the excess acid in stomach and give relief from acidity are called antacids.
For example: Sodium hydrogencarbonate (NaHCO3), magnesium hydroxide [Mg(OH)2] and aluminium hydroxide [Al(OH)3].
• Antihistamine: Also known as the anti-allergic drug, It suppresses the action of histamine (a compound released by cells in response to injury or any allergic and inflammatory reactions).
For example: Terfinadine, Cimetidine.
Some Important Chemicals Used in Food
Artificial Sweetening Agents: These are substances that are used in place of natural sugar.
Some common artificial sweeteners are given below:
(i) Aspartame: It is the most successful and widely used artificial sweetener. It is roughly 100 times as sweet as cane sugar. It is methyl ester of dipeptide formed from aspartic acid and phenylalanine.
Use of aspartame is limited to cold foods and soft drinks because it is unstable at cooking temperature.
(ii) Saccharin: It is the most popular artificial sweetener. It is about 400-500 times as sweet as cane sugar.
(iii) Sucrolose: It is a trichloro derivative of sucrose.
Its appearance and taste are like sugar. It is stable at cooking temperature.
These are the chemical substances that are added to prevent spoilage of food due to microbial growth.
Most common example is sodium benzoate used in soft drinks and acidic foods.
Antioxidants like BHT(butylated hydroxytoluene) and BHA (butylated hydroxyanisole) retard the action of oxygen on the food and help in the preservation of food materials.
Cleansing agents are the substance which remove dirt and have cleansing action in water.
These are of two types: (i) Soaps and (ii) Detergents
Soaps are sodium or potassium salts of higher fatty acids (containing 15-18 carbon atoms) e.g., stearic acid, oleic acid and palmitic acid.
Saponification: The process of producing soap by heating fat (glyceryl ester ~fatty acid) with aqueous sodium hydroxide solution, is termed as Saponification.
Soaps are not useful in hard water:
Hard water contains calcium and magnesium ions. The sodium salts present in soaps are converted to their corresponding calcium and magnesium salts which are precipitated as scum.
The insoluble scum sticks on the clothes hence reduces the cleaning capacity of soap.
Detergents are sodium salt of long chain linear alkyl benzene sulphonic acid. These are manufactured chemically from materials other than animal fats.
These can be used both in soft and hard water as they give foam even in hard water.
Detergents are three types of detergents:
(i) Anionic detergents: These are sodium salts of sulphonated long chain alcohols or hydrocarbons. In anionic detergents, the anionic part of the molecule is involved in the cleansing action. For example: alkyl benzene sulphonates are obtained by neutralising alkyl benzene sulphonic acids with alkali.
Use: They are also used in toothpastes.
(ii) Cationic detergents: These detergents are quarternary ammonium salts of amines with acetates, chlorides or bromides as anions.
Cationic part possess a long hydrocarbon chain and a positive charge on nitrogen atom. For example: Cetyltrimethylammonium bromide is a popular cationic detergent used in hair conditioners.
Use: They are used as germicides.
(iii) Non-ionic detergents: These are the detergents that does not contain any ion in their constitution. For example: Esters of high molecular mass formed by reaction of polyethylene glycol and stearic acid are non-ionic detergents.
Use: They are used in liquid dishwashing detergents.