HBSE Class 12th Previous Year Chemistry MCQs

Haryana Board (HBSE) Class 12 Previous Year Chemistry MCQs

Haryana Board (HBSE) 12th Exam: 2026

Q1: When vapours of a compound 'X' are passed over heated copper, the major product obtained is acetone. The compound 'X' is

1. n-Propyl alcohol
2. Isopropyl alcohol
3. Acetaldehyde
4. Propane

Correct Answer: B

Isopropyl alcohol undergoes dehydrogenation to form acetone when passed over heated copper.

\((CH_3)_2CH-OH \xrightarrow{Cu, 573 K} (CH_3)_2C=O + H_2\)

Haryana Board (HBSE) 12th Exam: 2026

Q2: Which of the following has the highest ionization enthalpy?

1. Oxygen
2. Nitrogen
3. Fluorine
4. Neon

Correct Answer: D

Neon, being a noble gas with stable configuration, has the highest ionization enthalpy.

Haryana Board (HBSE) 12th Exam: 2026

Q3: The IUPAC name of CH₃-CH=CH₂ is

1. Propane
2. Propene
3. Propyne
4. Methane

Correct Answer: B

CH₃-CH=CH₂ contains a double bond, hence named Propene.

Haryana Board (HBSE) 12th Exam: 2026

Q4: Which law explains the relationship between pressure and volume of a gas at constant temperature?

1. Boyle’s Law
2. Charles’ Law
3. Avogadro’s Law
4. Dalton’s Law

Correct Answer: A

Boyle’s Law states that pressure is inversely proportional to volume at constant temperature.

Haryana Board (HBSE) 12th Exam: 2026

Q5: Which of the following is an example of a heterogeneous catalyst?

1. Enzyme catalysis
2. Pt in hydrogenation of alkenes
3. Acid catalysis
4. Base catalysis

Correct Answer: B

Platinum acts as a solid catalyst in hydrogenation of alkenes, while reactants are in gaseous state.

Haryana Board (HBSE) 12th Exam: 2026

Q6: Which of the following is the strongest acid?

1. HF
2. HCl
3. HBr
4. HI

Correct Answer: D

Acid strength increases down the group; HI is the strongest acid among hydrogen halides.

Haryana Board (HBSE) 12th Exam: 2026

Q7: The hybridization of carbon in methane (CH₄) is

1. sp
2. sp²
3. sp³
4. None

Correct Answer: C

In methane, carbon forms four sigma bonds using sp³ hybrid orbitals.

Haryana Board (HBSE) 12th Exam: 2026

Q8: Which of the following is used as an anti-knock compound in petrol?

1. Tetraethyl lead
2. Benzene
3. Toluene
4. Acetone

Correct Answer: A

Tetraethyl lead was historically used as an anti-knock compound in petrol.

Haryana Board (HBSE) 12th Exam: 2026

Q9: Which of the following is a greenhouse gas?

1. CO₂
2. O₂
3. N₂
4. Ar

Correct Answer: A

Carbon dioxide is a major greenhouse gas responsible for global warming.

Haryana Board (HBSE) 12th Exam: 2026

Q10: Which of the following is an example of a redox reaction?

1. Neutralization of acid and base
2. Precipitation reaction
3. Zn + CuSO₄ → ZnSO₄ + Cu
4. Dissolution of sugar in water

Correct Answer: C

Zinc is oxidized and copper is reduced, hence it is a redox reaction.

Haryana Board (HBSE) 12th Exam: 2026

Q11: Which of the following has the highest electronegativity?

1. Oxygen
2. Fluorine
3. Chlorine
4. Nitrogen

Correct Answer: B

Fluorine is the most electronegative element in the periodic table.

Haryana Board (HBSE) 12th Exam: 2026

Q12: The compound used in the silvering of mirrors is

1. Silver chloride
2. Silver nitrate
3. Silver bromide
4. Silver oxide

Correct Answer: B

Silver nitrate is reduced to metallic silver during the silvering of mirrors.

Haryana Board (HBSE) 12th Exam: 2026

Q13: Which of the following is an example of a colloid?

1. Sugar solution
2. Salt solution
3. Milk
4. Alcohol-water mixture

Correct Answer: C

Milk is an emulsion colloid consisting of fat dispersed in water.

Haryana Board (HBSE) 12th Exam: 2026

Q14: The monomer of natural rubber is

1. Isoprene
2. Butadiene
3. Styrene
4. Vinyl chloride

Correct Answer: A

Natural rubber is a polymer of isoprene units.

Haryana Board (HBSE) 12th Exam: 2026

Q15: Which of the following is used in the manufacture of explosives?

1. Glycerol
2. Nitroglycerin
3. Glucose
4. Acetic acid

Correct Answer: B

Nitroglycerin is a key component in dynamite and other explosives.

Haryana Board (HBSE) 12th Exam: 2026

Q16: The pH of pure water at 25°C is

1. 6
2. 7
3. 8
4. 9

Correct Answer: B

Pure water is neutral at 25°C, hence pH = 7.

Haryana Board (HBSE) 12th Exam: 2026

Q17: Which of the following is a biodegradable polymer?

1. Polythene
2. Nylon
3. PHBV
4. Polystyrene

Correct Answer: C

PHBV (Polyhydroxybutyrate-co-valerate) is a biodegradable polymer.

Haryana Board (HBSE) 12th Exam: 2026

Q18: Which of the following is used as a moderator in nuclear reactors?

1. Graphite
2. Lead
3. Iron
4. Aluminium

Correct Answer: A

Graphite slows down neutrons and acts as a moderator in nuclear reactors.

Haryana Board (HBSE) 12th Exam: 2026

Q19: Which of the following is an ore of aluminium?

1. Hematite
2. Bauxite
3. Galena
4. Magnetite

Correct Answer: B

Bauxite is the principal ore of aluminium.

Haryana Board (HBSE) 12th Exam: 2026

Q20: Which of the following vitamins is fat-soluble?

1. Vitamin B
2. Vitamin C
3. Vitamin D
4. Vitamin H

Correct Answer: C

Vitamin D is fat-soluble, while B and C are water-soluble.

Haryana Board (HBSE) 12th Exam: 2026

Q21: Which of the following is used in the preparation of soaps?

1. Sodium hydroxide
2. Calcium hydroxide
3. Magnesium hydroxide
4. Ammonium hydroxide

Correct Answer: A

Soaps are prepared by saponification of fats with sodium hydroxide.

Haryana Board (HBSE) 12th Exam: 2026

Q22: Which of the following is a noble gas?

1. Oxygen
2. Nitrogen
3. Argon
4. Hydrogen

Correct Answer: C

Argon belongs to group 18 and is a noble gas.

Haryana Board (HBSE) 12th Exam: 2026

Q23: Which of the following is used in the manufacture of cement?

1. Limestone
2. Sand
3. Clay
4. All of these

Correct Answer: D

Cement is manufactured from limestone, clay, and sand.

Haryana Board (HBSE) 12th Exam: 2026

Q24: Which of the following is an example of a reducing sugar?

1. Glucose
2. Sucrose
3. Starch
4. Cellulose

Correct Answer: A

Glucose contains a free aldehyde group and acts as a reducing sugar.

Haryana Board (HBSE) 12th Exam: 2026

Q25: Which of the following is used in the vulcanization of rubber?

1. Sulphur
2. Phosphorus
3. Carbon
4. Silicon

Correct Answer: A

Sulphur is used to cross-link rubber molecules during vulcanization.

Haryana Board (HBSE) 12th Exam: 2026

Q26: Which of the following is used as a refrigerant?

1. Ammonia
2. Carbon dioxide
3. Freon
4. All of these

Correct Answer: D

Ammonia, CO₂, and Freon are all used as refrigerants.

Haryana Board (HBSE) 12th Exam: 2026

Q27: Which of the following is used in the treatment of cancer?

1. Cisplatin
2. Paracetamol
3. Aspirin
4. Penicillin

Correct Answer: A

Cisplatin is a platinum-based drug used in chemotherapy.

Haryana Board (HBSE) 12th Exam: 2026

Q28: Which of the following is used in the manufacture of glass?

1. Sodium carbonate
2. Calcium carbonate
3. Silica
4. All of these

Correct Answer: D

Glass is manufactured using silica, sodium carbonate, and calcium carbonate.

Haryana Board (HBSE) 12th Exam: 2026

Q29: Which of the following is used in the preservation of food?

1. Sodium benzoate
2. Acetic acid
3. Citric acid
4. All of these

Correct Answer: A

Sodium benzoate is commonly used as a preservative in food products.

Haryana Board (HBSE) 12th Exam: 2026

Q30: Which of the following is used in the manufacture of fertilizers?

1. Ammonia
2. Urea
3. Superphosphate
4. All of these

Correct Answer: D

Ammonia, urea, and superphosphate are all used in fertilizers.

Haryana Board (HBSE) 12th Exam: 2026

Q31: Which of the following is used in the manufacture of bleaching powder?

1. Calcium hydroxide
2. Calcium carbonate
3. Calcium sulphate
4. Calcium chloride

Correct Answer: A

Bleaching powder is prepared by passing chlorine gas over dry slaked lime (Ca(OH)₂).

Haryana Board (HBSE) 12th Exam: 2026

Q32: Which of the following is used in the manufacture of ammonia by Haber’s process?

1. Nitrogen and hydrogen
2. Nitrogen and oxygen
3. Nitrogen and chlorine
4. Nitrogen and carbon dioxide

Correct Answer: A

Haber’s process involves direct combination of nitrogen and hydrogen to form ammonia.

Haryana Board (HBSE) 12th Exam: 2026

Q33: Which of the following is used in the manufacture of soft drinks?

1. Carbon dioxide
2. Oxygen
3. Nitrogen
4. Hydrogen

Correct Answer: A

Carbon dioxide is dissolved under pressure to make soft drinks fizzy.

Haryana Board (HBSE) 12th Exam: 2026

Q34: Which of the following is used in the manufacture of rayon?

1. Cellulose
2. Protein
3. Starch
4. Glucose

Correct Answer: A

Rayon is a regenerated cellulose fiber obtained from wood pulp.

Haryana Board (HBSE) 12th Exam: 2026

Q35: Which of the following is used in the manufacture of Portland cement?

1. Limestone
2. Clay
3. Gypsum
4. All of these

Correct Answer: D

Portland cement is manufactured from limestone, clay, and gypsum.

Haryana Board (HBSE) 12th Exam: 2026

Q36: Which of the following is used in the manufacture of washing soda?

1. Sodium carbonate
2. Sodium bicarbonate
3. Sodium chloride
4. Sodium hydroxide

Correct Answer: A

Washing soda is chemically sodium carbonate decahydrate (Na₂CO₃·10H₂O).

Haryana Board (HBSE) 12th Exam: 2026

Q37: Which of the following is used in the manufacture of nitric acid?

1. Ammonia
2. Nitrogen
3. Oxygen
4. Hydrogen

Correct Answer: A

Nitric acid is manufactured by Ostwald’s process using ammonia as the raw material.

Haryana Board (HBSE) 12th Exam: 2026

Q38: Which of the following is used in the manufacture of plastics?

1. Ethylene
2. Propylene
3. Vinyl chloride
4. All of these

Correct Answer: D

Ethylene, propylene, and vinyl chloride are all monomers used in plastics manufacture.

Haryana Board (HBSE) 12th Exam: 2026

Q39: Which of the following is used in the manufacture of steel?

1. Iron ore
2. Coke
3. Limestone
4. All of these

Correct Answer: D

Steel is manufactured using iron ore, coke, and limestone in a blast furnace.

Haryana Board (HBSE) 12th Exam: 2026

Q40: Which of the following is used in the manufacture of soap as a cleansing agent?

1. Sodium stearate
2. Sodium chloride
3. Sodium carbonate
4. Sodium hydroxide

Correct Answer: A

Sodium stearate is the main cleansing agent present in soaps.

Haryana Board (HBSE) 12th Exam: 2026

Q41: Which of the following is used in the manufacture of chloroform?

1. Ethyl alcohol
2. Acetone
3. Carbon tetrachloride
4. Chloral

Correct Answer: D

Chloroform is prepared by reduction of chloral with bleaching powder.

Haryana Board (HBSE) 12th Exam: 2026

Q42: Which of the following is used in the manufacture of dynamite?

1. Nitroglycerin
2. Ammonium nitrate
3. Potassium nitrate
4. Sodium nitrate

Correct Answer: A

Dynamite is made by absorbing nitroglycerin in kieselguhr.

Haryana Board (HBSE) 12th Exam: 2026

Q43: Which of the following is used in the manufacture of baking powder?

1. Sodium bicarbonate
2. Sodium carbonate
3. Sodium hydroxide
4. Sodium chloride

Correct Answer: A

Baking powder contains sodium bicarbonate as the main ingredient.

Haryana Board (HBSE) 12th Exam: 2026

Q44: Which of the following is used in the manufacture of photographic films?

1. Silver chloride
2. Silver bromide
3. Silver nitrate
4. Silver oxide

Correct Answer: B

Silver bromide is light-sensitive and used in photographic films.

Haryana Board (HBSE) 12th Exam: 2026

Q45: Which of the following is used in the manufacture of paints?

1. Linseed oil
2. Turpentine oil
3. Both A and B
4. None of these

Correct Answer: C

Linseed oil is used as a binder and turpentine oil as a solvent in paints.

Haryana Board (HBSE) 12th Exam: 2026

Q46: Which of the following is used in the manufacture of artificial silk?

1. Cellulose
2. Protein
3. Starch
4. Glucose

Correct Answer: A

Artificial silk (rayon) is made from regenerated cellulose.

Haryana Board (HBSE) 12th Exam: 2026

Q47: Which of the following is used in the manufacture of stainless steel?

1. Chromium
2. Nickel
3. Iron
4. All of these

Correct Answer: D

Stainless steel is an alloy of iron, chromium, and nickel.

Haryana Board (HBSE) 12th Exam: 2026

Q48: Which of the following is used in the manufacture of Portland cement as a setting regulator?

1. Limestone
2. Clay
3. Gypsum
4. Sand

Correct Answer: C

Gypsum is added to cement to regulate its setting time.

Haryana Board (HBSE) 12th Exam: 2026

Q49: Which of the following is used in the manufacture of glass as the main raw material?

1. Silica
2. Sodium carbonate
3. Calcium carbonate
4. All of these

Correct Answer: A

Silica (SiO₂) is the principal raw material for glass manufacture.

Haryana Board (HBSE) 12th Exam: 2026

Q50: Which of the following is used in the manufacture of fertilizers as a source of nitrogen?

1. Ammonium sulphate
2. Urea
3. Calcium ammonium nitrate
4. All of these

Correct Answer: D

Ammonium sulphate, urea, and calcium ammonium nitrate are all nitrogenous fertilizers.

Read also:
CBSE Class 12th Previous Year Chemistry MCQs