NCERT Solutions For Class 12 Chemistry Chapter 16: Chemistry in Everyday Life

Ques 1. Why do we need to classify drugs in different ways?

Ans. The following factors are the reason for the drug’s classification:

 (i) The pharmacological impact is determined on:

This definition is useful for doctors. It provides a wide variety of medications to categorize medications for various conditions and different diseases.

(ii) Based on the action of the drugs:

This is based on the effect of the action of drugs on a specific biochemical process.

(iii) Building on the chemical structure:

The range of drugs that share the characteristics of a common structure will have similar pharmacological activity.

(iv) Building on the molecular objectives:

Many drugs have similar targets and actions. This difference is helpful in certain circumstances.

Ques 2. Explain the term, target molecules or drug targets as used in medicinal chemistry.

Ans. The primary molecule that several metabolic pathways that might result in particular illnesses are driven by is what the medicine targets. Proteins, nucleic acids, carbohydrates, and lipids are what the medication targets.

Drugs are chemical substances that interact with the active sites of important molecules to block those target molecules.

Ques 3. Name the macromolecules that are chosen as drug targets.

Ans. The macromolecules which are chosen as drug targets are carbohydrates, lipids, proteins, and nucleic acids.

Ques 4. Why should medicines not be taken without consulting doctors?

Ans. Since drugs can bind to several receptor sites, they should not be used without a doctor's advice and prescription. As a result, some receptor sites may suffer injury. When used in excess, medications might have negative consequences on different body parts. Thus, drugs may be lethal.

Read More: Antidepressant Drugs

Ques 5. Define the term chemotherapy.

Ans. Chemotherapy is the use of chemicals for therapeutic purposes. Chemical agents are used for illness prevention, diagnosis, and therapy as sources.

Ques 6. Which forces are involved in holding the drugs to the active site of enzymes?

Ans. The forces responsible for holding the drugs to the active site of enzymes are hydrogen bonding, ionic bonding, van der Waals forces, and dipole-dipole interaction.

Ques 7. While antacids and antiallergic drugs interfere with the function of histamines, why do these not interfere with the function of each other?

Ans. Only certain receptors are impacted by some medications. Antiallergic medications and antacids do not interact since they target separate receptors. Because of this, antacids and antiallergic medications don't affect each other's ability to affect histamine function.

Ques 8. Low level of noradrenaline is the cause of depression. What type of drugs are needed to cure this problem? Name two drugs.

Ans. Antidepressant medication is used to decrease the effects of depression. These medications have enzymes that help noradrenaline's neurotransmitter breakdown. The neurotransmitter can therefore activate the receptor for a longer amount of time since its metabolism is sluggish.

The two anti-depressant drugs are:

1. Phenelzine
2. Iproniazid

Read More: Stress Hormones

Ques 9. What is meant by the term “board spectrum antibiotics”? Explain.

Ans. Antibiotics are referred to as broad-spectrum antibiotics because they work well against both gram-positive and gram-negative bacteria. Such as chloramphenicol.

Acute fever, typhoid, meningitis, dysentery, TB, and certain UTIs are all treated with this. Vancomycin and ofloxacin are the other 2 antibiotics with a broad spectrum. Broad-spectrum antibiotics that are synthetically produced from penicillin include amoxicillin and ampicillin.

Structure of Chloramphenicol 

Ques 10. How do antiseptics differ from disinfectants? Give one example of each.

Ans. Antiseptics and disinfectants are very sorts of effective against microorganisms. While disinfectants specifically are used for items like floors, drainage systems, equipment, etc., antiseptics are utilized to specifically treat live tissues like cuts, wounds, damaged skin surfaces, and ulcers. 

Living tissues are harmed by disinfectants, particularly contrary to popular belief. Iodine works well as an antiseptic. Injuries specifically are treated with the iodine tincture, kind of contrary to popular belief. For a disinfectant, a phenol solution at 1% is used.

Read More:

Ques 11. Why are cimetidine and ranitidine better antacids than sodium hydrogen carbonate or magnesium or aluminium hydroxide?

Ans. The antacids magnesium hydroxide, sodium hydrogen carbonate, and aluminium hydroxide are used to neutralize excess hydrochloric acid in the stomach. However, the cause of the acid release has not been addressed. 

Because they reduce the source of the acidity, cimetidine and ranitidine are effective antacids. These medications stop histamine from connecting with the receptors found in the stomach's walls, which can lessen the amount of acid the stomach secretes.

Read More: Stomach Ulcer

Ques 12. Name a substance that can be used as an antiseptic as well as a disinfectant.

Ans. The chemical that has both antiseptic and disinfection properties is phenol. One per cent of the phenol solution should be used as a disinfectant, and 0.2 per cent of the solution can be used as an antiseptic.

Ques 13. What are the main constituents of Dettol?

Ans. Alpha-terpineol and chloroxylenol are the two main ingredients in Dettol.

Ques 14. What is the tincture of iodine? What is its use?

Ans. Iodine tincture, which contains 2-3% iodine in alcohol-water mixes, is typically given to wounds.

Ques 15. What are food preservatives?

Ans. Preservatives for food are substances that stop microbes from growing. They reduced spoilage. Sugar, table salt, vegetable oil, propanoic acid salts, and sodium benzoate are a few examples of food preservatives (C₆H₅COONa).

Ques 16. Why is the use of aspartame limited to cold foods and drinks?

Ans. Aspartame can only be used in cold foods and beverages since it cannot withstand the heat of cooking.

Ques 17. What are artificial sweetening agents? Give two examples.

Ans. Artificial sweeteners are the substances that are used to sweeten meals. Artificial sweeteners do not harm or add calories to our bodies in any way. Sucralose, aspartame, alitame, and saccharin are a few well-known artificial sweeteners.

Read More: Artificial Sweeteners

Ques 18. Name the sweetening agent used in the preparation of sweets for a diabetic patient.

Ans. For the preparation of desserts for diabetics, sweetening chemicals including saccharin, aspartame, and alitame are utilized.

Ques 19. What problem arises in using alitame as an artificial sweetener?

Ans. Alitame is a highly effective sweetener. When utilizing alitame as an artificial sweetener, it might be challenging to regulate the sweetness of the dish.

Ques 20. How are synthetic detergents better than soaps?

Ans. In comparison to soaps, synthetic detergents are utilized in both soft water and hard water. Soaps are ineffective in hard water. Therefore, synthetic detergents are superior to soaps.

Ques 21. Explain the following terms with suitable examples.

1. Cationic detergent
2. Anionic detergent
3. Non- ionic detergent

Ans. (i) Cationic Detergent: Quaternary ammonium salts of chlorides, bromides, or acetates are used in cationic detergents. Because the cationic component of these detergents has a long hydrocarbon chain and a positive charge on the N atom, they are known as cationic detergents. Using cetyltrimethylammonium bromide as an example.

(ii) Anionic Detergents: Anionic detergents can be basically classified into two types: 

• Sodium alkyl sulfates: These anionic detergents, sodium salts of long-chain alcohols, are known as sodium alkyl sulfates. Alcohols are first treated with strong sulfuric acid, and subsequently with sodium hydroxide, to prepare them.
• Sodium alkylbenzene sulphonates: These anionic detergents, known as sodium alkylbenzene sulphonates, are sodium salts of long-chain alkyl benzene sulphonic acids. They are made by alkylating benzene with long-chain alkyl halides or alkenes in a Friedel-Crafts process. The final product is processed with sodium hydroxide and concentrated sulfuric acid in that order. Sodium 4-(1-dodecyl) benzenesulfonate is one example (SDS).

(iii) Non-Ionic Detergents: These detergents' molecules don't include any ions. These detergents are high molecular mass alcohol esters. They are created by stearic acid and polyethylene glycol interacting.

Read More: Sulphonation

Ques 22. What are biodegradable and non-biodegradable detergents? Give one example of each.

Ans. Detergents that break down by bacterial action are biodegradable. They do include hydrocarbons in straight chains. Consider sodium lauryl sulfate. The detergents that cannot be broken down by microorganisms are considered non-biodegradable. They have highly branched hydrocarbon chains.

For instance, benzene sulphonate with sodium -4- (1, 3, 5, 7- tetramethyl octyl)

Ques 23. Why do soaps not work in hard water?

Ans. Soaps include salts of sodium or potassium that contain long-chain fatty acids. Calcium and magnesium are found in hard water. Insoluble calcium or magnesium salts of fatty acids are created when the ions displace sodium or potassium from soaps that are dissolving in hard water. Sort out the scum of insoluble salts. Because of this, soaps don't work in hard water.

Ques 24. Can you use soaps and synthetic detergents to check the hardness of water?

Ans. Since soap precipitates in hard water but not in mild, it may be used to measure the hardness of the water. Contrarily, synthetic detergents cannot be used to determine the hardness of water since they do not precipitate in either soft or hard water.

Ques 25. Explain the cleansing action of soaps. 

Ans. Two components make up soap: a hydrophobic (repels water) and a hydrophilic (dissolves water) element. For the hydrophilic regions of the distinctions to project outside the oil droplet and the hydrophobic parts to cling to the oil droplet, soap molecules create micelles surrounding the oil droplet (dirt). The stearate ions (together with the dirt) are drawn into the water by the hydrophilic, polar components, which remove the dirt from the fabric.

Read More: Cleaning Capacity of Soap in Soft & Hard Water

Ques 26. If the water contains dissolved calcium hydrogen carbonate, out of soaps and synthetic detergents which one will you use for cleaning clothes?

Ans. Synthetic detergents are often used for washing. These ions result in the formation of insoluble salts when they dissolve in water along with useless calcium ions. Synthetic detergents are dissolved in water containing calcium ions, and the resultant soluble salts act as cleaning agents.

Ques 27. Label the hydrophilic and hydrophobic parts in the following compounds.

1. CH₃ (CH₂)₁₀ CH₂OSO₃ – Na⁺
2. CH₃ (CH₂) ₁₅ N⁺ (CH₃)₃ Br^- 
3. CH₃ (CH₂) ₁₆COO (CH₂CH₂O)_n CH₂CH₂OH

Ans. (i) [CH₃ (CH₂)₁₀CH₂]^- Hydrophobic Part, [OSO_3-Na⁺]^- Hydrophilic Part

(ii) [CH₃(CH₂)₁₅]^- Hydrophobic Part, [N⁺(CH₃)₃^-Br]^- Hydrophilic Part

(iii) [CH₃(CH₂)₁₆ ]^- Hydrophobic Part, [COO(CH₂CH₂O)_nCH₂CH₂OH]^- Hydrophilic Part.

Do Check Out: