Important Questions for CBSE Class 12 Chemistry Chapter 16 - Chemistry in Everyday life 2024-25

Very Short Answer Type Questions (1 Mark)

1. Which among the following is a semi synthetic modification of penicillin: Erythromycin, Ampicillin, Tetracycline, Ofloxacin.

Ans: Ampicillin is the semi-synthetic modification of penicillin, because it has a broad spectrum. 

2. Substances produced wholly or partly by chemical synthesis, which in low concentrations inhibits the growth or destroys microorganisms by intervening in their metabolic processes. Identify the substance.

Ans: Because of their low toxicity in people and animals, antibiotics are employed as medicines to treat infections. An antibiotic is a drug generated entirely or partially by chemical synthesis that inhibits or kills bacteria by interfering with their metabolic activities at low doses.

3. Drugs are classified as:

Aspirin – analgesic

Chlordiazepoxide – tranquilizer

Penicillin – antibiotic

Mention on what basis the above classification is done?

Ans: Analgesics decrease or eliminate pain without impairing awareness, producing mental disorientation, incoordination, or paralysis, or causing other nervous system abnormalities. Aspirin, morphine, heroin, and codeine are examples of analgesics.

Tranquilisers are a family of pharmacological substances that are used to alleviate stress as well as mild to severe mental illnesses. These induce a sensation of well-being, which relieves worry, tension, impatience, and excitement. Tranquilizers include chlordiazepoxide, meprobamate, veronal, amytal, nembutal, luminal, and phenelzine, to name a few.

Antibiotics are substances generated entirely or partially by chemical synthesis that, at low doses, inhibit or kill bacteria by interfering with their metabolic activities. Penicillin, Erythromycin, Tetracycline, Ofloxacin, Chloramphenicol, and Aminoglycosides are examples of antibiotics.

4.     

Identify the type of detergent given in the above structure.

Ans: The detergent given in the above structure iscetyltrimethylammonium bromide also called Cetrimide. It is made up of a mixture of different ammonium salts .'

5. Which of the following drug combinations is not correct and state why?

Chloramphenicol – broad spectrum antibiotic 

Equanil – sedative

Phenacetin – antipyretic 

Bithional – tranquilizer

Ans: From the above list, bithional is not a tranquilizer, it is an antibacterial disinfectant. Bithional is used in soaps not only as an antibacterial, but also to decrease odours caused by microbial breakdown of organic compounds on the skin.

2 Mark Questions 

1. Analysis of water in a place shows that the water contains Magnesium Chloride. The people in that place are advised to use detergents for washing clothes. Why?

Ans: The two most frequent minerals that make water "hard" are calcium and magnesium dissolved in water. As the calcium and magnesium concentration increases in the water its degree of hardness also increases, and is connected to the concentration of multivalent cations dissolved in the water. Synthetic detergents are considerably better cleaners than soaps since they are made up of numerous petroleum compounds. They are also antimicrobial and can readily displace the calcium and magnesium ions in hard water, making them suitable for use in hard water.

2. Pick out the odd one from the following and mention why? 

Erythromycin, penicillin, tetracycline, chloramphenicol

Ans: The above mentioned species are all antibiotics, but amongst them penicillin exists as tablets and rest all are bacterias used to treat infections.

3. Antiallergics and antacids are antihistamines. Can antiallergics be used to reduce the acidity of the stomach? Give a plausible reason for your answer.

Ans: Antihistamines are anti allergy medications. Antacids, on the other hand, are not antihistamines. As a result, they can't be used interchangeably. Anti allergic medicines, often known as antihistamines, are used to treat allergic responses, which are caused by the release of histamine in the body. Acidity in the stomach is treated with antacids. Antacids, such as sodium bicarbonate, magnesium and aluminium hydroxide can be used to neutralise the excess acid.

4. Following drugs are used as analgesics. One among them is different from others. Identify it and state the reason. 

Morphine, Heroin, Aspirin, Codeine

Ans: Although the above given drugs come under the category of analgesics but only aspirin is different from the rest. Morphine, heroin and codeine are narcotic drugs whereas aspirin is an anti-inflammatory analgesic used in the treating pain and inflammation. 

5. The structure below is given as:

(i). Identify the compound.

Ans: The compound given in the structure is bithionol. It is an antiseptic

(ii). What is its use?

Ans: Being an antiseptic, bithionol is used to cure wounds and treat minor cuts.

6. Birth control pills essentially contain a mixture of synthetic estrogen and progesterone. What are estrogen and progesterone? Why are they used in birth control pills?

Ans: Estrogen and progesterone are female hormones that are linked to ovulation and menstruation in women. They also play a role in pregnancy. Birth control pills contain a mix of both hormones and act in the following ways:

1. Birth control pills operate by halting the entire development of the ovum each month, causing it to no longer absorb sperm and therefore preventing conception.

2. If the woman's egg develops, such tablets thicken the cervical mucus near the uterus' entrance, making it difficult for sperm to reach the egg.

3. Furthermore, tablets can alter the uterine lining just enough to prevent an egg from developing in the uterus.

7. Sodium and Potassium soaps are only used for cleaning purposes. Why?

Ans: Soaps with sodium salts are made by heating fat (the glycerol ester of a fatty acid) with an aqueous sodium hydroxide solution. Soaps containing sodium and potassium are the only ones that are soluble in water and may be used for cleaning. Potassium soaps are gentler on the skin than sodium soaps.

8. Detergents containing unbranched chains are more preferable than those containing branched chains. State the reason.

Ans: Detergents containing branched chain hydrocarbons are non-biodegradable because bacteria have difficulty degrading them. As a result, straight chain hydrocarbon detergents are favoured over branched chain hydrocarbon detergents.

9. Low level of noradrenaline is the cause of depression. Suggest drugs to cure this problem?

Ans: Depression is caused by a lack of noradrenaline. Antidepressant medications are required to treat this condition. They stop noradrenaline breakdown enzymes from working. As a result, noradrenaline metabolism is delayed, allowing the neurotransmitter to activate its receptor for longer durations of time. Iproniazid and phenelzine are two examples of such medications.

3 Mark Questions 

1. Observe the diagram and answer the questions given below:

(i). Name the drug target.

Ans. Sometimes the drugs do not bind to the active site of the enzyme. They attach to the allosteric site of the enzyme, which is distinct from the active site. The inhibitor's interaction to the allosteric site alters the structure of the active site, making it unrecognisable to the substrate.

(ii). What is meant by an allosteric site?

Ans. The allosteric site is a molecule's ability to stimulate or inhibit (or turn off) enzyme activity. It's not the same as an enzyme's active site, which is where substrates bind. When allosteric activators attach to the allosteric site, the enzyme binds to the substrate more efficiently, and the process speeds up.

(iii). Mention the role of inhibitors.

Ans. Enzyme inhibitors are chemicals that alter an enzyme's catalytic characteristics, slowing or stopping catalysis in some circumstances. Blocking or altering the active site is how these inhibitors function.

2. Observe and identify the steps a, b, c from the diagram given below:

From the above diagram:

Step a: In the first step, the receptor receives the chemical messenger. Receptors are proteins that are essential for the body's communication system. Because their binding sites are distinct in form, structure, and amino acid content, receptors exhibit selectivity for one chemical messenger over the other.

Step b: In the second step, the shape of the receptor changes. Chemical messengers are substances that transmit messages between neurons and between neurons and muscles in the body. They bind to receptor proteins at their binding sites. The shape of the receptor site alters to fit a messenger, allowing the message to be transferred into the cell. The message is delivered to the recipient through a chemical messenger. 

Step c: In the third step, the structure regains its shape. Antagonists are drugs that attach to the receptor site and prevent it from performing its normal action. When message blocking is necessary, these are beneficial. Agonists are drugs that act like the natural messenger by activating the receptor. When a natural chemical messenger is unavailable, they are beneficial.

3. Sodium hydrogen carbonate and ranitidine are used as antacids. Which one is a better choice? Why?

Ans: Antacids such as sodium hydrogen carbonate, magnesium hydroxide, and aluminium hydroxide function by neutralising excess hydrochloric acid in the stomach. However, the underlying reason for excess acid production remains unaddressed. Cimetidine and ranitidine are superior antacids because they regulate acidity at its source. These medicines stop histamine from interacting with the receptors in the stomach walls. As a result, the quantity of acid produced by the stomach is reduced, which is why cimetidine and ranitidine are superior antacids than sodium hydrogen carbonate, magnesium hydroxide, or aluminium hydroxide.

4. Identify the following substances:

(i). It is about 550 times as sweet as cane sugar and excreted from the body in urine unchanged.

Ans: Saccharin, also known as ortho-sulfabenzamide, was the first widely used artificial sweetening ingredient. Since its discovery in 1879 , it has been employed as a sweetening agent. It is 550  times sweeter than cane sugar. It remains unaltered when it leaves the body and is eliminated in urine.

(ii). It is 100 times as sweet as cane sugar and its use is limited to cold food and soft drinks as it is unstable at cooking temperature.

Ans: The most popular and extensively used artificial sweetener is aspartame. It is around 100 times sweeter than cane sugar. It is a dipeptide made up of aspartic acid and phenylalanine that is methyl esterified. Because aspartame is unstable at cooking temperatures, it is only used in cold meals and soft drinks.

(iii). It is a trichloro derivative of Sucrose and it is stable at room temperature.

Ans: Sucralose is a trichloro derivative of sucrose. It is a substitute for sugar with no calories. It is present in nature as a white powdery substance and is also known as artificial sweetener.

Revise the important topics and subtopics covered in CBSE Class 12 Chemistry Chapter 16 with the help of these important questions and answers given above. While going through these important questions and answers, you will get a thorough understanding of the topics like drugs and their classifications, drug-target interaction, therapeutic action of different classes of drugs, chemicals in food, and cleansing agents. Our subject experts for Chemistry have provided concise logical explanations for each question discussed above. 

So you can rely upon these questions and answers for learning this chapter. You can also sign up for our customized online classes and 1:1 classes to get the best guidance for clearing your doubts and preparing for your exams.

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