JEE Chemistry Chemistry In Everyday Life MCQs Set 10

Answer: (c) They contain a mixture of estrogen and progesterone derivatives

Explanation:
1. Oral contraceptives contain a mixture of synthetic estrogen and progesterone derivatives (for example norethindrone with ethynylestradiol).
2. They suppress ovulation, and progesterone does not enhance it.

Teacher's Note:
1. The pills mimic pregnancy hormone levels, so ovulation does not occur.

Answer: (a) Aspirin belongs to narcotic analgesics

Explanation:
1. Aspirin is a non-narcotic analgesic, so statement (a) is false.
2. It relieves pain, lowers fever and, because it inhibits platelet aggregation, helps prevent heart attacks.

Teacher's Note:
1. Narcotic analgesics are morphine, codeine and related compounds.

Answer: (a) Some tranquilizers function by inhibiting the enzymes which catalyse the degradation of noradrenaline

Explanation:
1. Antidepressant tranquilizers such as iproniazid and phenelzine inhibit the enzymes that break down noradrenaline, so more of it remains and mood is lifted.
2. Tranquilizers are not narcotics, they do affect nerve transmission, and they do not act as analgesics or antipyretics.

Teacher's Note:
1. Tranquilizers treat anxiety and mental disorders; analgesics treat pain.

Answer: (a) syphilis

Explanation:
1. Paul Ehrlich developed salvarsan (arsphenamine) as the first synthetic antibacterial against the spirochaete that causes syphilis.

Teacher's Note:
1. Salvarsan was the first 'magic bullet' chemotherapeutic drug.

Answer: (b) tranquilizers

Explanation:
1. Antidepressants such as iproniazid and phenelzine are tranquilizers: they act on the central nervous system to relieve anxiety and depression.
2. Analgesics relieve pain and antihistamines counter allergy.

Teacher's Note:
1. Tranquilizers include antidepressants, barbiturates (for sleep) and meprobamate (equanil).

Answer: (d) Bithional

Explanation:
1. Bithional (bithionol) is a phenolic antiseptic added to medicated soaps.
2. Sodium lauryl sulphate and sodium dodecylbenzenesulphonate are detergents, and rosin is a filler that improves lathering.

Teacher's Note:
1. Medicated soaps contain antiseptics such as bithional or chloroxylenol.

Answer: (b) a tranquilizer

Explanation:
1. Equanil (meprobamate) is a tranquilizer used to control depression and hypertension.

Teacher's Note:
1. Equanil should be remembered with the other tranquilizers: valium, serotonin analogues and barbiturates.

Answer: (b) Sodium rosinate

Explanation:
1. Sodium rosinate, made by adding rosin during soap making, gives a good lather.
2. Sodium carbonate and trisodium phosphate are builders, and sodium stearate is the soap itself.

Teacher's Note:
1. Rosin also keeps the soap soft and gives it a golden colour.

Answer: (b) A non-ionic detergent: the polyethylene glycol ether of nonylphenol

Explanation:
1. Liquid dishwashing detergents are non-ionic detergents, formed from a polyethylene glycol chain and an alkylphenol (for example stearic acid esters or nonylphenol ethoxylates).
2. They have no charge and are not affected by hard water.
3. Cetyltrimethylammonium bromide is a cationic detergent and sodium lauryl sulphate an anionic detergent.

Teacher's Note:
1. Non-ionic detergents do not ionise, so they are used in liquid household cleaners.

Answer: (c) Vitamins

Explanation:
1. Drugs interact with biomolecules such as carbohydrates, lipids, proteins (enzymes, receptors) and nucleic acids.
2. Vitamins are not considered target molecules.

Teacher's Note:
1. The main drug targets are macromolecules of the cell.

Answer: (c) Generally a strong covalent bond is formed between the inhibitor and the enzyme

Explanation:
1. Most drug-type inhibitors bind reversibly through weak interactions (hydrogen bonds, ionic and van der Waals forces), so a strong covalent bond is not generally formed.
2. The other statements are correct.

Teacher's Note:
1. Competitive inhibitors compete with the substrate for the active site; non-competitive inhibitors bind elsewhere and change the shape of the active site.

Answer: (d) Sucralose

Explanation:
1. Sucralose is a chlorinated derivative of sucrose that is stable at cooking temperature and is not metabolised, so it adds no calories.
2. Aspartame decomposes on heating, and sucrose and glucose provide calories.

Teacher's Note:
1. Sucralose is about 600 times sweeter than sucrose.

Answer: (c) The shape of the receptor does not change during attachment of the messenger

Explanation:
1. When the messenger binds, the receptor changes shape; this triggers the cell response.
2. So statement (c) is incorrect.

Teacher's Note:
1. Receptor binding causes a conformational change that passes the message into the cell.

Answer: (b) Sodium hydrogen carbonate

Explanation:
1. Salt, sugar (in jams) and benzoic acid (as sodium benzoate) prevent microbial growth.
2. Sodium hydrogen carbonate (baking soda) is a leavening agent, not a preservative.

Teacher's Note:
1. Common preservatives: table salt, sugar, vegetable oils, sodium benzoate and sorbic acid.

Answer: (a) (i) and (ii) only

Explanation:
1. Sulphapyridine and Prontosil (which is converted in the body to sulphanilamide) are sulphonamide drugs.
2. Salvarsan is an arsenic compound, and Nardil (phenelzine) is an antidepressant.

Teacher's Note:
1. Sulpha drugs are derivatives of sulphanilamide.

Answer: (a) (i) and (ii) only

Explanation:
1. Iproniazid and phenelzine (Nardil) are antidepressants (monoamine oxidase inhibitors).
2. Equanil is a tranquilizer used for depression and hypertension, and salvarsan is an antibacterial.

Teacher's Note:
1. Antidepressant drugs inhibit the enzyme that degrades noradrenaline.

Answer: (a) (ii) and (iv) only

Explanation:
1. Sodium hydrogen carbonate and magnesium hydroxide (milk of magnesia) neutralise excess stomach acid safely.
2. Sodium carbonate is too alkaline, and aluminium hydroxide (not carbonate) is the aluminium antacid.

Teacher's Note:
1. Excess NaHCO3 can make the stomach alkaline and increase acid secretion, so Mg(OH)2 and Al(OH)3 are preferred.

Answer: (a) (i) and (iv) only

Explanation:
1. Cimetidine (Tagamet) and ranitidine (Zantac) block H2 receptors in the stomach lining, reducing acid release.
2. Brompheniramine and terfenadine block H1 receptors and are used for allergies.

Teacher's Note:
1. Antacids neutralise acid; H2-antagonists stop its release.

Answer: (a) tranquilizers (neurologically active drugs)

Explanation:
1. These barbiturates act on the central nervous system and produce sleep or sedation, so they are tranquilizers (neurologically active drugs).
2. They do not relieve pain, counter allergies or kill bacteria.

Teacher's Note:
1. Barbiturates are sleep inducers (hypnotics).

Answer: (a) (i), (iii) and (iv) only

Explanation:
1. Quaternary ammonium (cationic) detergents are germicidal.
2. Synthetic detergents form no insoluble salts with Ca2+ and Mg2+ and lather even in cold or hard water, and they are not soaps (not sodium salts of fatty acids).
3. Highly branched chains are not biodegraded by bacteria, so (ii) is false.

Teacher's Note:
1. Straight-chain detergents are biodegradable; branched chains caused foam pollution in rivers.

Answer: (a) methyl isocyanate

Explanation:
1. Methyl isocyanate, \(\ce{CH3-N=C=O}\), leaked in December 1984 after water entered the storage tank.

Teacher's Note:
1. Phosgene is a reagent used in making methyl isocyanate, not the leaked gas.

Answer: (d) Non-biodegradable pollutant

Explanation:
1. DDT is an organochlorine insecticide that is very stable and fat soluble.
2. It is not broken down by microorganisms and accumulates in food chains.

Teacher's Note:
1. Biomagnification of DDT leads to thinning of bird egg shells.