PHYSICS-15-10- 11th (PQRS) SOLUTION

https://docs.google.com/document/d/1uqLNw_gMQpgT57Z7KPTUFkJD4sEysCTn/edit?usp=sharing&ouid=109474854956598892099&rtpof=true&sd=true Chemistry in Everyday Life Chemicals in medicines - Analgesics, tranquilizers, antiseptics, disinfectants, antimicrobials, antifertility drugs, antibiotics, antacids, antihistamins - their meaning and common examples, Chemicals in food - Preservatives, artificial sweetening agents - common examples, Cleansing agents - Soaps and detergents, cleansing action. CHEMICALS IN MEDICINES Chemical substances used for treatment of disease and for reducing the suffering from pain are called medicines or drugs. Chemotherapy is the science in which chemicals are used for the treatment of diseases. Chemicals used in chemotherapy are frequently classified according to their action. Thus analgesics relieve pain, antipyretics reduce temperature, anti-inflammatories control inflammation and antibiotics kill bacteria and other micro-organisms. Antipyretics Antipyretics are substances used to bring down body temperature in high fever. e.g. Aspirin, Phenacetin and Paracetamol. Aspirin is a common antipyretic. It should not be taken empty-stomach as it generates salicylic acid which may ulcerate stomach wall and can cause bleeding. Calcium and sodium salts of aspirin are more soluble and less harmful. C H A P T E R CHAPTER INCLUDES Chemicals in medicines Antipyretics Analgesics Antibiotics Tranquilizers Chemical in food Chemical OCOCH3 COOH OH C2H5 Preservatives Artificial Sweetening NH — C — CH3 NHCOCH3 Agents Cleansing agents Analgesics Aspirin O 4–acetamidophenol (Paracetamol) Phenacetin Soaps and Detergents There are drugs used for relieving pain. Aspirin and some other antipyretics act as analgesics also. Certain narcotics (which produce sleep and unconsciouness) are also used as analgesics. Examples of narcotics are morphine, marijuana, codeine pethidine and heroin. They are known to be habit-forming. RO C6H5 COOC2H5 O R = H, Morphine R = CH3, Codeine N — CH3 N CH3 H Pethidine hydrochloride Cl– TEACHING CARE Online Live Classes https://www.teachingcare.com/ +91-9811000616 JEE main Chemistry in Everyday Life Antibiotics Antibiotics are chemical substances produced by micro-organisms (bacteria, fungi and moulds) that can inhibit the growth or even destroy other micro-organisms. Penicillin is used against large number of infections caused by various bacteria. It is an effective drug for pneumonia, bronchitis, sore throat and abcesses. Other antibiotics like streptomycin and tetracycline are used against diseases caused by bacteria. Some antibiotics are specific for certain diseases, for example, streptomycin for tuberculosis and chloramphenicol for typhoid. Broad spectrum antibiotics are medicines effective against several different types of harmful micro-organisms, e.g., tetracycline, chloramphenicol. Penicillin has a narrow spectrum. Ampicillin and amoxicillin are derivatives of penicillin. Chloramphenicol is a broad spectrum antibiotic. It is rapidly absorbed from the gastro-intestinal tract and hence can be given orally in case of typhoid, dysentry, acute fever, certain form of urinary infections, meningitis and pneumonia. Sulpha drugs like sulphanilamide, sulphadiazine and sulphaguanidine act against micro-organisms like antibiotics and have been used in place of them. Tranquillizers The chemical substances which act on the central nervous system and has a calming effect to reduce anxiety are specified as tranquillizers. They are used for the treatment of mental diseases they are also used for making sleeping pills. They are habit forming and should not be taken without proper prescription. They do not add any energy into the person but help to remove the emotional distress or depression and the person is able to work to his full capacity. The most commonly used transquillisers are barbituric acid and its substituted derivatives such as luminal and seconal. CHEMICAL IN FOOD During processing of food a number of chemicals are added to it to increase its life and also to make it more attraction. Some of these chemicals which are present in food are discussed below. Chemical preservatives : Growth of micro organisms in a food material can be inhibited by adding certain chemical substance. Such chemical substances which are added to food materials to prevents their spoilage are known as chemical preservatives. The most commonly used preservatives includes table salt, sugar, vegetable oils and sodium benzoate. Sodium benzoate is used in limited quantities salts of sorbic acid and propanoic acid are also used as preservatives. Artificial sweetening agent : Sugar is the natural sweeting agent however excess of sugar leads of many diseases such as obesity, diabetes. Many artificial sweetening agents have been isolated which are more sweeter than sugar. Ortho-sulphobenzimide also called saccharin is the first popular sweetening agent. Some other artificial sweetener are aspartame, sucrolose, alitame etc. CLEANSING AGENT Two types of detergents are used as cleansing agent. These are soaps and synthetic detergents. These help in removal of fats which bind other materials to the fabric or skin. These days detergents are much in vogue and get preference over soaps because they work even in hard water. Synthetic detergents are classified into three main categories namely anionic, cationic and non-ionic and each category has its specific use detergents with straight chain of hydrocarbons are preferred over branched chain as the latter are non-biodegradable and consequently cause environmental pollution. ❑ ❑ ❑