CBSE Class 12 Chemistry Chemistry in Everyday Life Questions Answers

Question. Tranquilisers are substances used for the treatment of :
a. Cancer
b. AIDS
c. Mental diseases
d. Physical disorders
Answer : C

Question. The major factor in causing global warming is:
a. Increase in oxygen concentration in atmosphere
b. Decrease in carbon dioxide concentration in atmosphere
c. Increase in carbon dioxide concentration in atmosphere
d. Decrease in atmospheric nitrogen
Answer : D

Question. Lichens are important in the studies on atmospheric pollution because they:
a. Can grow in polluted atmosphere
b. Can readily multiply in polluted atmosphere
c. Efficiently purify the atmosphere
d. Are very sensitive to pollutants like sulphur dioxide
Answer : C

Question. Acid rain is caused by or recent reports of acid rain in some industrial cities are due to the effect of atmospheric pollution by:
a. Excessive release of CO₂ by burning of fuels like wood and charcoal, cutting of forests and increased animal population
b. Excessive release of NO₂ and SO₂ in atmosphere by burning of fossil fuel
c. Excessive release of NH₃ by industrial plants and coal gas
d. Excessive release of CO in atmosphere by incomplete combustion of coke, charcoal and other carbonaceous fuel in paucity of oxygen
Answer : D

Question. Alizarin gives a red colour by mordanting it with the sulphate of a metal. The metal ion involved is:
a. Cr³⁺
b. Fe³⁺
c. Al³⁺
d. Sn²⁺
Answer : C

Question. Man–engineered ecosystem is:
a. Forest
b. Grassland
c. Cropland
d. Marine
Answer : C

Question. Which one of the following statement is not true?
a. Oxides of sulphur, nitrogen and carbon are the most widespread air pollutant.
b. pH of drinking water should be between 5.5 and 9.5.
c. Concentration of DO below 6 ppm is good for the growth of fish.
d. Clean water would have a BOD value of less than 5 ppm
Answer : C

Question. Which of the following represents a synthetic detergent?

CHEMISTRY IN EVERYDAY LIFE

Q1. Name two types of chemical messengers.

Answer: Hormones and neurotransmitters.

Teacher's Note:
a) Chemical messengers carry signals from one cell or organ to another.
b) Hormones act through the blood, while neurotransmitters act across nerve synapses.

Q2. Name the antibiotic used in typhoid fever.

Answer: Chloramphenicol.

Teacher's Note:
a) Chloramphenicol is a broad spectrum antibiotic.
b) Typhoid is caused by the bacterium Salmonella typhi.

Q3. Name a Broad spectrum Antibiotic.

Answer: Chloramphenicol.

Teacher's Note:
a) A broad spectrum antibiotic acts against a wide range of bacteria.
b) Ampicillin and ciprofloxacin are other examples.

Q4. Name the Medicine which can act as analgesic as well as antipyretic .

Answer: Aspirin.

Teacher's Note:
a) Analgesics relieve pain, and antipyretics reduce fever.
b) Aspirin is also used to prevent blood clotting.

Q5. Name the constituents of Dettol.

Answer: Chloroxylenol and terpineol.

Teacher's Note:
a) Dettol is an antiseptic used for cleaning wounds and surfaces.
b) Chloroxylenol is the main active antiseptic in Dettol.

Q6. Why is Ethanal added to Soap ?

Answer: Ethanol (printed as ethanal) is added to soap to make it transparent. It dissolves the soap and makes it clear.

Teacher's Note:
a) The printed word 'Ethanal' should read ethanol, the alcohol used in transparent soap.
b) Transparent soaps are made by dissolving soap in ethanol.

Q7. Name an ant acid which prevent the formation of acid in the stomach.

Answer: Ranitidine.

Teacher's Note:
a) Ranitidine blocks histamine receptors that trigger acid release.
b) Cimetidine is another example of this type of antacid.

Q8. Why is glycerol is added to shaving soap?

Answer: Glycerol is added to shaving soap to prevent rapid drying.

Teacher's Note:
a) Glycerol is a humectant that keeps the soap moist.
b) It also makes the soap smoother on the skin.

Q9. Give an example of bacteriocidal antibiotic.

Answer: Penicillin.

Teacher's Note:
a) A bactericidal antibiotic kills bacteria.
b) A bacteriostatic antibiotic only stops their growth.

Q10. Name a drug used in mental depression .

Answer: Equanil.

Teacher's Note:
a) Equanil (meprobamate) is a tranquiliser used to treat stress and mental disorders.
b) Tranquilisers act on the central nervous system.

Q11. Name a few artificial sweatners

Answer: Saccharin and aspartame.

Teacher's Note:
a) Artificial sweeteners are many times sweeter than sugar.
b) They provide very few calories, so they suit diabetic patients.

Q12. What type drugh is phenacetine?

Answer: Analgesic (and antipyretic). Phenacetin is used to relieve pain and reduce fever, and it is not an antibiotic.

Teacher's Note:
a) The printed answer 'Antibiotic' is wrong; phenacetin is a pain reliever.
b) Antibiotics kill or stop the growth of microorganisms.

Q13. What are pathogens?

Answer: Pathogens are disease causing organisms.

Teacher's Note:
a) Pathogens include bacteria, viruses, fungi and protozoa.
b) Pathogens enter the body through food, water or air.

Q14. Name two Narcotics which are used as analgesics >

Answer: Morphine and codeine.

Teacher's Note:
a) Narcotic analgesics relieve severe pain.
b) They can be addictive, so they are used under medical supervision.

Q15. What is Chemotherapy?

Answer: Chemotherapy is the use of chemicals for the treatment of disease.

Teacher's Note:
a) Chemotherapy is used for treating infections and cancer.
b) Antibiotics are a common example of chemotherapy.

Q16. Mention a few drug targets .

Answer: Carbohydrates, lipids, proteins and nucleic acids are drug targets.

Teacher's Note:
a) A drug target is a biomolecule with which a drug interacts.
b) Proteins such as enzymes and receptors are the most common drug targets.

Q17. Define a Tanquilizer.

Answer: A tranquiliser is a drug that acts on the central nervous system (CNS) to reduce anxiety and stress.

Teacher's Note:
a) Tranquilisers are also used in mild or severe mental disorders.
b) Valium is an example of a tranquiliser.

Q18. Define Soap .

Answer: Soap is a sodium or potassium salt of higher fatty acids.

Teacher's Note:
a) Soaps are made by alkaline hydrolysis of fats or oils.
b) Sodium soaps are hard, and potassium soaps are soft.

Q19. Why are detergents preferred over soaps ?

Answer: Detergents are preferred over soaps because they can be used even in hard water.

Teacher's Note:
a) Soaps form scum with the calcium and magnesium ions of hard water.
b) Detergents do not form scum, so they clean better in hard water.

Q20. What is a Bacteriostatic drug ?

Answer: A bacteriostatic drug inhibits the growth of disease causing organisms.

Teacher's Note:
a) It stops the bacteria from multiplying but does not kill them.
b) Tetracycline is an example of a bacteriostatic drug.

Chapter 16. Chemistry in everyday life
Section A (One Mark Question)

1. Name a drug which is an analgesic and antipyretic? [1 Mark]

Answer: Aspirin.

Teacher's Note:
a) Aspirin relieves pain and reduces fever.

2. Elucidate the structural differences between biodegradable and non- bio degradable detergent? [1 Mark]

Answer: Biodegradable detergents have straight chains, for example sodium dodecyl benzene sulphonate. Non-biodegradable detergents have branched chains, for example sodium (1,3,5,7-tetramethyloctyl) benzene sulphonate.

Teacher's Note:
a) Straight chains are broken down by bacteria, so they are biodegradable.

3. Why are ranitidine and cimetidine better antacids than sodium bicarbonate? [1 Mark]

Answer: Sodium bicarbonate, if taken in excess, makes the stomach alkaline, so more HCl is released, which causes ulcers. Ranitidine prevents the interaction of histamine with the stomach wall, so less HCl is released.

Teacher's Note:
a) Ranitidine and cimetidine are H2 receptor blockers.

4. Though saccharin is 550 times sweeter than sugar it is used as a sweetening agent by diabetic patient. Why? [1 Mark]

Answer: Saccharin is eliminated in urine and provides less calorie, so it is safe for diabetic patients.

Teacher's Note:
a) Saccharin is not metabolised by the body.

5. Distinguish between drugs and medicine. [1 Mark]

Answer: A drug is a chemical substance used for the diagnosis, treatment or prevention of disease, and some drugs are addictive. A medicine is a drug used in a safe, therapeutic dose to cure or relieve disease and is not addictive when used as prescribed.

Teacher's Note:
a) The printed key says drugs are addictive, but only some drugs are.

6. If water contains (CaHCO3)2,out of soap and detergent which one will you choose for cleaning clothes.? [1 Mark]

Answer: Detergent will be chosen, because calcium ions in the hard water form scum with soap, while detergents do not.

Teacher's Note:
a) The formula should be written as Ca(HCO3)2 (calcium hydrogen carbonate).

7. Why cationic detergent has limited use? [1 Mark]

Answer: Cationic detergents are quaternary ammonium salts of amines with acetates, chlorides or bromides. They have germicidal properties but are expensive, so their use is limited.

Teacher's Note:
a) Cationic detergents are mostly used as germicides and in hair conditioners.

8. While antacids and antiallergic drugs interfere with the function of histamine. Why do not interfere with the function of each other?Explain. [1 Mark]

Answer: Antacids and antiallergic drugs act on different receptors. Histamine causes allergy and also causes acidity due to the release of HCl. Antihistamines remove allergy, while antacids remove acidity.

Teacher's Note:
a) Antiallergic drugs block H1 receptors.

9. Aspirin helps in prevention of heart attack. [1 Mark]

Answer: Aspirin prevents heart attack because of its anti-blood clotting action.

Teacher's Note:
a) Low dose aspirin stops platelets from clumping together.

9. Give One example of drugs used as antiseptics and disinfectants.? [1 Mark]

Answer: 0.2% solution of phenol is an antiseptic, while its 1% solution is a disinfectant.

Teacher's Note:
a) Antiseptics are safe for use on living tissue.

Question. How carbon monoxide, emitted by automobiles, prevents transport of oxygen in the body tissues:
a. By changing oxygen into carbon dioxide
b. By destroying the haemoglobin
c. By forming a stable compound with haemoglobin
d. By obstructing the reaction of oxygen with haemoglobin
Answer : C

Question. Among the following analgesics, select the odd one:
a. Codeine
b. Morphine
c. Aspirin
d. Heroin
Answer : C

Question. The gas leaked from a storage tank of the Union Carbide plant in Bhopal gas tragedy was:
a. Ammonia
b. Phosgene
c. Methylisocyanate
d. Methylamine
Answer : C

Question. Which one of the following statement regarding photochemical smog is not correct?
a. Photochemical smog is formed through photochemical reaction involving solar energy.
b. Photochemical smog does not cause irritation in eyes and throat.
c. Carbon monoxide does not play any role in photochemical smog fraction.
d. Photochemical smog is an oxidizing agent in character.
Answer : B

Question. Select the correct statements:
a. 2-3% alcohol-water mixture is known as tincture of iodine.
b. Iodoform solution is antiseptic for wounds.
c. Boric acid solution is antiseptic for eyes.
d. All of these
Answer : D

Question. Identify the wrong statement among the following?
a. Chlorofluorocarbons are responsible for ozone layer depletion.
b. Green house effect is responsible for global warming.
c. Ozone layer does not permit infrared radiation from the sun to reach the earth.
d. Acid rain is mostly because of oxides of nitrogen and sulphur.
Answer : C

Question. When rain is accompanied by a thunderstorm, the collected rain water will have a pH value:
a. Which depends upon the amount of dust in air
b. Slightly lower than that when rain water is without thunderstorm
c. Slightly higher than that when the thunderstorm is not there
d. Uninfluenced by occurrence of thunderstorm
Answer : B

Question. Drugs which do not bind to the enzyme’s active site, but to different site. This different site is called:
a. Inhibition Site
b. Competitive Site
c. Allosteric Site
d. None of these
Answer : C

Question. Among the following, which is not a traquilizer?
a. Noradrenaline
b. Chlordiazepoxide
c. Meprobamate
d. All are tranquilizers
Answer : D

Question. Morphine narcotic are obtained from:
a. Opium
b. Avena
c. Datura
d. All of these
Answer : A

Question. Select the correct statement:
a. Enzymes are proteins in nature and are biological catalysts
b. Proteins which help in communication are called receptors
c. Polar molecules across the cell membrane are called carrier proteins
d. All are correct
Answer : D

Question. Select the correct statement:
a. Antagonists are the substances which inhibit the natural function of receptor site.
b. Agonists are the drugs that mimic the natural messenger by switching on the receptor
c. Substrates may bind to active site of enzyme through a variety of interactions such as ionic bonding, H-bonding, van dar wasls interaction or dipole-diople interaction.
d. All of these
Answer : D

Assertion and Reason

Note: Read the Assertion (A) and Reason (R) carefully to mark the correct option out of the options given below:
a. If both assertion and reason are true and the reason is the correct explanation of the assertion.
b. If both assertion and reason are true but reason is not the correct explanation of the assertion.
c. If assertion is true but reason is false.
d. If the assertion and reason both are false.
e. If assertion is false but reason is true.

Question. Assertion: Individual is the unit of Ecology.
Reason: Biome occurs at the top of ecological hierarchy.
Answer : C

Question. Assertion: Relationship between sea anemone and hermit crab is said to be an example of obligate mutualism.
Reason: Obligate mutualism is a positive (beneficial) interaction between two species.
Answer : E

Question. Assertion: Speciation is always a very slow process.
Reason: Genetic drift is one of the causes for speciation.
Answer : E

Question. Assertion: Removal of keystone species doesn’t cause any serious disruption in the functioning of the community.
Reason: Keystone species are low in abundance (or biomass) than the dominant species.
Answer : D

Question. Assertion: In S-shaped growth form, the population may abruptly crash after attaining a peak value.
Reason: Exponential growth cannot be sustained infinitely due to environmental resistance.
Answer : E

Question. Assertion: α,β and γ rays emit by disintegration of atomic nuclei of radioactive elements.
Reason: Nuclear fallout is shown by radioactive elements.
Answer : B

Question. Assertion: Microclimate generally differs from the prevailing regional climatic conditions.
Reason: Microclimate represents the climatic conditions that prevail at local scale or in areas of limited size.
Answer : A

Question. Assertion: Biotic community has higher position than population in ecological hierarchy.
Reason: Population of similar individuals remains isolated in the community.
Answer : C

Question. Assertion: Ecological equivalents possess similar types of adaptations.
Reason: Ecological niche is the total interaction of a species with environment.
Answer : B

Question. Assertion: The main cause of Bhopal gas tragedy was phosgene.
Reason: Phosgene is a volatile liquid.
Answer : E

Question. Assertion: CO₂ causes green house effect.
Reason: Other gases do not show such effect.
Answer : C

Question. Assertion: Tetracyclin is a broad spectrum antibiotic.
Reason: Tetracyclin is effective against a number of types of bacteria, large viruses and typhus fever.
Answer : A

Question. Assertion: Methylmercury is a highly persistent kind of pollutant that accumulates in food chains.
Reason: Mercury pollution is responsible for Minamata disease.
Answer : B

Question. Assertion: Water pollutants are measured by BOD.
Reason: If BOD is more, the water is polluted.
Answer : A

Question. Assertion: Climate is said to entail the short term properties of the atmosphere (such as temperature, rainfall etc.) at a given place and time.
Reason: Temperature and rainfall are the most important factors which determine the climate of an area.
Answer : E

Question. Assertion: Heliophytes, generally have low photosynthetic, respiratory and metabolic activities.
Reason: This is an adaptation of heliophytes to high intensity of light.
Answer : D

Question. Assertion: Fluorescein is an adsorption indicator.
Reason: Fluorescein indicator is a dye.
Answer : B

Question. Assertion: Antiseptics are applied to living tissues.
Reason: Iodine is a powerful antiseptic.
Answer : B

Question. Assertion: The drugs which act on the central nervous system and help in reducing anxiety are called antibiotics.
Reason: Pencillin is an antibiotic.
Answer : C

Question. Assertion: Equanil is a tranquilizer.
Reason: Equanil is used to cure depression and hypertension.
Answer : A

Question. Assertion: Sedatives are given to patients who are mentally agitated and violent.
Reason: Sedatives are used to suppress the activities central nervous system.
Answer : A

Match the Column

Question. Match the following:

a. A→2, B→3, C→4, D→1
b. A→2, B→1, C→3, D→4
c. A→2, B→1, C→4, D→3
d. A→4, B→3, C→1, D→2
Answer : C

Question. Match the following and choose the correct combinations from the options given:

a. A→4, B→3, C→2, D→1
b. A→1, B→3, C→2, D→4
c. A→2, B→3, C→4,
D→1 d. A→3, B→2, C→4, D→1
Answer : D

Integer

Question. How many of the following compounds are gaseous air pollutants?
(i) CO (ii) NO (iii) NO₂ (iv) CO₂ (v) SO₂ (vi) H₂S (vii)
SO₃ (viii) O₃ (ix) Fumes (x) Smoke
Answer : 8

Question. The co-existence of biotic components and abiotic components is called an ecosystem. How many of the following are abiotic components?
(i) Micro-organisms (ii) Animals (iii) Plants (iv) CO₂ (v) N₂
(vi) S (vii) P (viii) Proteins (ix) Carbohydrates (x) Temperature (xii) Humidity
Answer : 8

Question. How many of the following compounds are barbituric acid derivative tranquilizers?
(i) Barbital (ii) Meprobamate (iii) Equanil (iv) Luminal
(v) Seconal (vi) Valium (vii) Serotonin (viii) Chlordiazepoxide.
Answer : 3

Question. How many gaseous species are present in mesosphere and thermosphere?
(i) O₂^⊕ (ii) O⁻²₂ (iii) 2 O⁻₂ (iv) NO^⊕ (v) N₂^⊕ (vi) Atoms of C
(vii) O^⊕ (viii) Atoms of N(ix) Atoms of S (x) Atoms of O
Answer : 6

Question. How many gases are responsible for green house effect?
(i) CO₂ (ii) CO (iii) CH₄ (iv) N₂O (v) NO (vi) NO₂
(vii) Chloroflurocarbons (CFCs) (viii) O₃ (ix) Water vapours (x) SO₂
Answer : 6

Question. How many acids are present in acid rain?
(i) H₂CO₃ (ii) HClO₄ (iii) H₂SO₄ (iv) HNO₃
(v) HCl (vi) H₃PO₄ (vii) CH₃COOH
Answer : 3

Question. How many of the following compounds are broad spectrum antibiotics?
(i) Penicillin F (ii) Penicillin K (iii) Tetracycline
(iv) Ampicillin (v) Amoxycillin (vi) Chloramhenicol
(vii) Vancomycin (viii) Ofloxacin (ix) Dysidazinine
Answer : 6

vHow many of the following compounds are neurotransmitters (chemical messangers)?
(i) Noradrenaline (ii) Dopamine (iii) Serotonin
(vi) Adrenaline (v) Acetycholine
Answer : 4

Question. How many of the following compounds are antipyretics?
(i) Morphine (ii) Codeine (iii) Heroin (iv) Aspirin
(v) Phenacetin (v) Paracetamol (vii) Ibuprofen
(viii) Diclofenac sodium (ix) Naproxen (x) Novalgin
Answer : 4

Question. How many of the following compounds are artificial sweeteners?
(i) BHT (ii) BHA (iii) Histamine (IC) Aspartame
(v) Sucralose (vi) Alitame (vii)Saccharin (viii) Ranitidine (zantac) (ix) sodium benzoate (x) Salts of sorbic acid.
Answer : 4