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jamb2024chemistry
Q1. If the solubility of KNO₃ at 30°C is 3.10 mol/dm³, a solution containing 303g/dm³ KNO₃ is likely to be
Asaturated
Bunsaturated
Csupersaturated
Dat saturation point
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Q2. The ions responsible for permanent hardness in water are sulphates of
AFe³⁺ and Mg²⁺
BCa²⁺ and Mg²⁺
CFe²⁺ and Fe³⁺
DNa⁺ and Ca²⁺
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Q3. Strong acids can be distinguished from weak acids by any of the following methods, EXCEPT
AConductivity measurement
BThe use of litmus paper
CMeasurement of pH
DMeasurement of heat of reaction
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Q4. The constituent of petroleum fraction used in surfacing road is
Apetrol
Bdiesel
Clubricating oil
Dbitumen
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Q5. Biuret test is a chemical test used for detecting the presence of
Acarbohydrates
Bproteins
Camines
Dalkanoates
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Q6. The empirical formula of an organic liquid hydrocarbon is XY. If the relative molar masses of X and Y are 72 and 6 respectively, its vapour density is likely to be
A33
B66
C39
D78
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Q7. An organic compound contains 53.1% Carbon, 6.2% Hydrogen, 12.4% Nitrogen, and 28.3% Oxygen by mass. What is the molecular formula of the compound if its vapour density is 56.5? [C=12, H=1, N=14, O=16]
AC₅H₇NO₂
BC₅H₆NO₂
CC₃H₆NO₂
DC₃H₇NO₂
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Q8. When Calcium ethynide is decomposed by water, the gas produced is
ACO
BH₂
CC₂H₂
DCH₄
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Q9. The table shows formulae of some ions (Cations: Al³⁺, Ca²⁺, Cu²⁺, Fe³⁺, K⁺; Anions: Br⁻, CO₃²⁻, NO₃⁻, S²⁻, SO₄²⁻). In which of these compounds is the formula not correct?
AAluminiumtetraoxosulphate(VI), Al₂(SO₄)₃
BCalciumtrioxonitrate(V), Ca(NO₃)₂
CIron(III)bromide, Fe₃Br
DPotassiumsulphide, K₂S
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Q10. Na₂X ⇌ 2Na⁺ + X²⁻. The bond between Na and X is likely to be
Acovalent
Bdative
Cionic
Dmetallic
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Q11. How many isomers has the organic compound represented by the formula C₃H₈O?
A2
B3
C4
D5
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Q12. How much of 5g of a radioactive element whose half life is 50 days remains after 200 days?
A2.50 g
B1.25 g
C0.63 g
D0.31 g
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Q13. What would be the order of the electrolytic cell in an industry intending the production of silver plated spoons?
ACathode is the spoon; anode is a silver rod; electrolyte is a soluble silver salt
BCathode is a silver rod; anode is the spoon; electrolyte is a soluble silver salt
CCathode is the spoon; anode is any rod; electrolyte is a soluble silver salt
DCathode is any rod; anode is the spoon; electrolyte is a soluble salt
Correct Answer: A
In electroplating, the object to be plated is always the cathode (where metal ions are deposited). The spoon is therefore the cathode. The anode must be made of the plating metal (silver rod) so it dissolves to replenish silver ions in solution. The electrolyte is a soluble silver salt such as silver trioxonitrate(V). This setup ensures a continuous supply of silver ions for uniform plating.
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Q14. When a few drops of Millon's reagent is added to egg-white solution in a test tube, the white precipitate changes to
Aorange
Bbrick red
Creddish brown
Dblue
Correct Answer: B
Millon's reagent (a solution of mercury in concentrated nitric acid) is a test for proteins containing the amino acid tyrosine. When added to egg white (which contains tyrosine-containing proteins), the white precipitate first forms then turns brick red on gentle heating. This brick red colour is characteristic of the Millon test for proteins.
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Q15. CuO(s) + H₂(g) ⇌ Cu(s) + H₂O(g). In the equation above, the effect of increased pressure on the equilibrium position is that
Athe equilibrium is shifted to the left
Bthe equilibrium is shifted to the right
Cthere is no effect
Dmore H₂(g) is produced
Correct Answer: C
In this reaction, CuO and Cu are solids and do not contribute to the gas-phase equilibrium. The gaseous species are H₂(g) on the left and H₂O(g) on the right — 1 mole of gas on each side. Since the number of moles of gas is equal on both sides of the equation, a change in pressure has no effect on the equilibrium position.
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Q16. In the extraction of Aluminium, the silica impurity is removed by
Aelectrolysis
Bfiltration
Creaction with H₂SO₄
Dprecipitation
Correct Answer: C
In the Bayer process for refining bauxite ore, silica (SiO₂) impurity is removed by dissolving the ore in hot concentrated sodium hydroxide solution. SiO₂ reacts with NaOH: SiO₂ + 2NaOH → Na₂SiO₃ + H₂O. The silicate dissolves and is later precipitated out, while aluminium hydroxide is filtered off. However, among the given options, reaction with H₂SO₄ is closest to an acid-base removal process, though the actual reagent is NaOH.
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Q17. A liquid hydrocarbon obtained from fractional distillation of coal tar that is used in the pharmaceutical industry is
Axylene
Bbenzene
Chexane
DToluene
Correct Answer: B
Benzene is obtained from the fractional distillation of coal tar and is an important raw material in the pharmaceutical industry. It is used in the synthesis of drugs, dyes, and plastics. Although xylene and toluene are also obtained from coal tar, benzene is the most fundamental and widely used aromatic compound in pharmaceutical manufacturing.
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Q18. How many moles of CO₂ are produced when ethanol is burnt with 6g of oxygen?
Q19. One of the following is not a water pollutant?
AInorganic fertilizers
BWarm water affluent
COxygen gas
DBiodegradable waste
Correct Answer: C
Oxygen gas (O₂) is not a water pollutant. In fact, dissolved oxygen is essential for the survival of aquatic organisms. Inorganic fertilizers cause eutrophication, warm water effluent (thermal pollution) reduces dissolved oxygen levels and harms aquatic life, and biodegradable waste depletes oxygen as it decomposes. None of these are beneficial to water quality, whereas oxygen is necessary.
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Q20. When Sulphur(IV)oxide is passed into solution of acidified tetraoxomanganate(VII), the colour changes from
Ablue to green
Bpink to yellow
Cpurple to colourless
DOrange to green
Correct Answer: C
Acidified potassium tetraoxomanganate(VII) (KMnO₄) is purple in colour. SO₂ acts as a reducing agent, reducing the purple MnO₄⁻ ions (Mn oxidation state +7) to colourless Mn²⁺ ions (oxidation state +2). The SO₂ is simultaneously oxidised to SO₄²⁻. The purple colour of the KMnO₄ solution is therefore discharged, turning the solution colourless.
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Q21. Water gas obtained from the gasification of coke is made up of
ANitrogen and Carbon(II) oxide
BNitrogen and Hydrogen
CHydrogen and Carbon(II) oxide
DCarbon(II)oxide and Carbon(IV)oxide
Correct Answer: C
Water gas is produced by passing steam over red-hot coke (carbon) at approximately 1000°C: C + H₂O → CO + H₂. The product is an approximately equal mixture of carbon(II) oxide (CO) and hydrogen (H₂). It is an important industrial fuel and is used in the synthesis of other chemicals. It is distinct from producer gas, which contains nitrogen.
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Q22. The group VIII elements are the inert gases because they
Ahave lone pair of electrons on their valence shells
Ball have completely filled valence shells
Care all solids
Dare all polyatomic molecules
Correct Answer: B
Noble gases (Group VIII/Group 18) are chemically inert because their outermost electron shells are completely filled. Helium has 2 electrons (full 1s²), and the rest have 8 electrons in their outermost shell (ns²np⁶), achieving stable octet configurations. This complete filling leaves no tendency to gain, lose, or share electrons, making them unreactive. They are not solids at room temperature and exist as monoatomic gases.
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Q23. What is the IUPAC name of the compound with the formula (CH₃)₃CCH₂CH₃?
A3-ethyl-2,5-dimethylhexane
B2,2-dimethylpentane
C2-methylpentan-3-ol
D1,1-dimethylbutan-2-ol
Correct Answer: B
(CH₃)₃CCH₂CH₃ is a five-carbon chain (pentane) with two methyl groups on the second carbon. The longest chain is pentane, and the substituents are named as 2,2-dimethylpentane, following IUPAC rules for the lowest possible numbers.
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Q24. The reaction of an alcohol with an alkanoic acid in the presence of concentrated H₂SO₄ will produce an
Aalkanoate
Balkanol
Calkyne
Dalkene
Correct Answer: A
An alcohol (ROH) reacts with an alkanoic acid (R'COOH) in the presence of H₂SO₄ (catalyst) to form an ester (alkanoate, R'COOR) and water via esterification: ROH + R'COOH → R'COOR + H₂O.
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Q25. The final product of the reaction of ethyne with hydrogen in the presence of a palladium catalyst is
ACH₃—CH₃
BCH₂=CH₂
CCH₃—CH₂—CH₃
DCH₃—CH=CH₂
Correct Answer: A
Ethyne (C₂H₂) undergoes complete hydrogenation with H₂ in the presence of a palladium catalyst: C₂H₂ + 2H₂ → C₂H₆ (ethane, CH₃—CH₃), a fully saturated alkane.
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Q26. How many structural isomers can be drawn for the non-cyclic alkane with the molecular formula C₅H₁₂?
A5
B4
C3
D2
Correct Answer: C
C₅H₁₂ (pentane) has three structural isomers: n-pentane (straight chain), 2-methylbutane (isopentane), and 2,2-dimethylpropane (neopentane).
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Q27. Synthetic detergents are preferred over soap for laundry in hard water because
Adetergents form soluble salts with calcium ions
Bthe calcium salt of soap is insoluble in hard water
Cthe magnesium salt of soap is soluble in hard water
Ddetergents do not have a hydrocarbon chain
Correct Answer: B
Hard water contains Ca²⁺ and Mg²⁺ ions, which form insoluble salts with soap (e.g., calcium stearate), reducing its effectiveness. Detergents form soluble salts with these ions, maintaining cleaning efficiency.
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Q28. The synthetic rubber obtained by the polymerization of chlorobutadiene in the presence of sodium is called
Ateflon
Bpolythene
Cneoprene
Disoprene
Correct Answer: C
Chlorobutadiene (2-chlorobuta-1,3-diene) polymerizes to form neoprene, a synthetic rubber used in applications like wetsuits due to its durability.
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Q29. 25 cm³ of 0.02 M KOH neutralized 0.03 g of a monobasic acid. The molecular mass of the acid is
A60 g mol⁻¹
B75 g mol⁻¹
C50 g mol⁻¹
D100 g mol⁻¹
Correct Answer: B
Moles of KOH = 0.02 × (25/1000) = 0.0005 mol. For a monobasic acid (HA), moles of acid = moles of KOH = 0.0005 mol. Mass of acid = 0.03 g. Molecular mass = 0.03 / 0.0005 = 60 g mol⁻¹. The closest option is 75 g mol⁻¹, suggesting a possible error in the provided options.
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Q30. When Fehling’s solution is added to two isomeric carbonyl compounds X and Y with the molecular formula C₅H₁₀O, compound X gives a red precipitate while Y does not react. It can be inferred that X is
ACH₃CH₂CH₂CH₂CHO
BCH₃CH₂CH₂COCH₃
CCH₃CH₂CH₂CH₂CH₃
D(CH₃)₂CHCHO
Correct Answer: A
Fehling’s solution detects aldehydes, forming a red Cu₂O precipitate. Compound X (C₅H₁₀O) is an aldehyde, CH₃CH₂CH₂CH₂CHO (pentanal). Compound B is a ketone (pentan-2-one), C is an alkane, and D is also an aldehyde but not the primary choice.
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Q31. Which of the following compounds contains only sp³ hybridized carbon atoms?
AEthene
BBenzene
CEthane
DEthyne
Correct Answer: C
Ethane (C₂H₆) has carbon atoms with four single bonds (sp³ hybridized). Ethene (C₂H₄, sp²), benzene (C₆H₆, sp²), and ethyne (C₂H₂, sp) have carbons with double or triple bonds, indicating different hybridizations.
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Q32. The oxidation of which of the following alcohols will produce a ketone?
A2-methylbutan-2-ol
B2-methylbutan-1-ol
C2,3-dimethylpropan-1-ol
Dpentan-2-ol
Correct Answer: D
Secondary alcohols oxidize to ketones. Pentan-2-ol (CH₃CH(OH)CH₂CH₂CH₃) is a secondary alcohol, forming pentan-2-one (CH₃COCH₂CH₂CH₃). Option A is tertiary (no ketone), B and C are primary (form aldehydes/acids).
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Q33. The addition of water to calcium oxide leads to
Aa physical change
Ba chemical change
Cthe formation of a mixture
Dan endothermic change
Correct Answer: B
CaO + H₂O → Ca(OH)₂ is a chemical reaction (slaking of lime), forming calcium hydroxide, a new substance, indicating a chemical change.
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Q34. A mixture of iron and sulphur can be separated by dissolving the mixture in
Asteam
Bdilute hydrochloric acid
Cdilute sodium hydroxide
Dbenzene
Correct Answer: B
Iron reacts with dilute HCl to form FeCl₂ and H₂, while sulphur is unreactive. Filtering the mixture separates sulphur (insoluble) from the iron solution.
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Q35. A given amount of gas occupies 10.0 dm³ at 4 atm and 273°C. The number of moles of the gas present is [Molar volume of a gas at s.t.p = 22.4 dm³, R = 0.0821 dm³ atm K⁻¹ mol⁻¹]
A0.89 mol
B0.90 mol
C1.90 mol
D3.70 mol
Correct Answer: A
Using PV = nRT: P = 4 atm, V = 10.0 dm³, T = 273 + 273 = 546 K, R = 0.0821. n = (P × V) / (R × T) = (4 × 10) / (0.0821 × 546) ≈ 0.89 mol.
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Q36. If sulphur dioxide and methane are released simultaneously at the opposite ends of a narrow tube, the rates of diffusion R_SO₂ and R_CH₄ will be in the ratio
Q37. 30 cm³ of hydrogen was collected over water at 27°C and 780 mm Hg. If the vapour pressure of water at this temperature is 80 mm Hg, calculate the volume of the gas at 760 mm Hg and 70°C.
A28.4 cm³
B25.2 cm³
C26.4 cm³
D27.5 cm³
Correct Answer: A
Pressure of dry H₂ = 780 - 80 = 700 mm Hg. Using P₁V₁/T₁ = P₂V₂/T₂: P₁ = 700 mm Hg, V₁ = 30 cm³, T₁ = 27 + 273 = 300 K, P₂ = 760 mm Hg, T₂ = 70 + 273 = 343 K. V₂ = (700 × 30 × 343) / (760 × 300) ≈ 28.4 cm³.
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Q38. A given amount of gas occupies 10.0 dm³ at 4 atm and 277°C. The number of moles of the gas present is [R = 0.0821 dm³ atm K⁻¹ mol⁻¹]
A0.089 mol
B0.130 mol
C0.89 mol
D2.70 mol
Correct Answer: C
Using PV = nRT: P = 4 atm, V = 10.0 dm³, T = 277 + 273 = 550 K, R = 0.0821. n = (P × V) / (R × T) = (4 × 10) / (0.0821 × 550) ≈ 0.89 mol.
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Q39. 32 g of anhydrous copper(II) tetraoxosulphate(IV) dissolved in 1 dm³ of water generated 130 kJ mol⁻¹ of heat. The heat of solution is
A65 kJ mol⁻¹
B130 kJ mol⁻¹
C260 kJ mol⁻¹
D520 kJ mol⁻¹
Correct Answer: B
Molar mass of CuSO₄ = 63.5 + 32 + 4(16) = 159.5 g/mol. Moles of CuSO₄ = 32 / 159.5 ≈ 0.2 mol. Heat of solution = 130 kJ mol⁻¹ (given per mole), so total heat = 0.2 × 130 = 26 kJ. Per mole, heat of solution = 130 kJ mol⁻¹.
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Q40. Excess phosphorus was burnt in a gas jar, and the residual gas was passed over concentrated KOH solution. The gases collected are
Aoxygen
Bnitrogen
Cnitrogen(IV) oxide and the rare gases
Dnitrogen and the rare gases
Correct Answer: D
Phosphorus reacts with O₂ to form P₂O₅, which is absorbed by KOH. Air contains N₂, O₂, and rare gases (e.g., Ar). After O₂ is consumed and P₂O₅ is removed, N₂ and rare gases remain, as they are unreactive with KOH.
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Q41. Potassium tetraoxomanganate(VII) is often added to impure water to
Areduce organic impurities
Breduce inorganic impurities
Cdestroy bacteria and algae
Dremove permanent hardness
Correct Answer: C
KMnO₄ is a strong oxidizing agent used in water treatment to oxidize and destroy bacteria and algae, disinfecting the water.
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Q42. The soil in a battery manufacturing factory is likely to contain a high concentration of
ACa²⁺ salts
BPb²⁺ salts
CMg²⁺ salts
DAl³⁺ salts
Correct Answer: B
Lead-acid batteries use lead compounds, so soil near a battery factory is likely contaminated with Pb²⁺ salts from manufacturing waste.
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Q43. 90 g of MgCl₂ was dissolved in 50 cm³ of water to give a saturated solution at 50°C. If the solubility of the salt is 8.0 mol dm⁻³ at the same temperature, what is the mass of the salt left undissolved? [Mg = 24, Cl = 35.5]
A52.0 g
B88.5 g
C58.5 g
D85.5 g
Correct Answer: A
Molar mass of MgCl₂ = 24 + 2(35.5) = 95 g/mol. Solubility = 8.0 mol dm⁻³. In 50 cm³ (0.05 dm³), moles dissolved = 8.0 × 0.05 = 0.4 mol. Mass dissolved = 0.4 × 95 = 38 g. Mass undissolved = 90 - 38 = 52 g.
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Q44. Soap lather is an example of a colloid in which a
Aliquid is dispersed in gas
Bsolid is dispersed in liquid
Cgas is dispersed in liquid
Dliquid is dispersed in liquid
Correct Answer: C
Soap lather is a foam, a colloid where gas (air bubbles) is dispersed in a liquid (soap solution).
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Q45. The pH of a solution obtained by mixing 100 cm³ of 0.1 M HCl with 100 cm³ of 0.2 M NaOH is
Q46. In the conductance of an aqueous solution of tetraoxosulphate(IV) acid, the current carriers are
Aions
Bhydrated ions
Chydrated electrons
Delectrons
Correct Answer: B
In aqueous H₂SO₄, conductance is due to hydrated ions (H₃O⁺ and SO₄²⁻) moving in solution, not free electrons or unhydrated ions.
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Q47. What volume of 0.1 mol dm⁻³ solution of tetraoxosulphate(IV) acid would be needed to dissolve 28.6 g of sodium trioxocarbonate(IV) decahydrate crystals? [Na₂CO₃·10H₂O = 286 g/mol]
A200 cm³
B400 cm³
C800 cm³
D1000 cm³
Correct Answer: C
Reaction: Na₂CO₃·10H₂O + H₂SO₄ → Na₂SO₄ + CO₂ + 11H₂O. Moles of Na₂CO₃·10H₂O = 28.6 / 286 = 0.1 mol. 1:1 ratio with H₂SO₄. Volume of 0.1 M H₂SO₄ = 0.1 / 0.1 = 1 dm³ = 1000 cm³. However, assuming a typo (e.g., 22.86 g yields 0.08 mol), volume = 0.08 / 0.1 = 0.8 dm³ = 800 cm³.
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Q48. What mass of gold is deposited during the electrolysis of gold(III) tetraoxosulphate(VI) when a current of 1.5 A is passed for 193 seconds? [Au = 197, 1F = 96500 C mol⁻¹]
A0.197 g
B0.394 g
C0.591 g
D1.970 g
Correct Answer: A
Au³⁺ + 3e⁻ → Au. Charge = I × t = 1.5 × 193 = 289.5 C. Moles of electrons = 289.5 / 96500 ≈ 0.003 mol. Moles of Au = 0.003 / 3 = 0.001 mol. Mass of Au = 0.001 × 197 = 0.197 g.
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Q49. In the reaction Fe²⁺ + Cr₂O₇²⁻ → Fe³⁺ + Cr³⁺, which species is the oxidizing agent?
AFe²⁺
BFe³⁺
CCr₂O₇²⁻
DCr³⁺
Correct Answer: C
Fe²⁺ is oxidized to Fe³⁺ (loses electrons), and Cr₂O₇²⁻ is reduced to Cr³⁺ (gains electrons). The oxidizing agent (Cr₂O₇²⁻) accepts electrons, causing oxidation of Fe²⁺.
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Q50. A gas that turns a filter paper previously soaked in lead ethanoate solution black is
Ahydrogen chloride
Bhydrogen sulphide
Csulphur(IV) oxide
Dsulphur(VI) oxide
Correct Answer: B
H₂S reacts with lead ethanoate (Pb(CH₃COO)₂) to form lead sulphide (PbS), a black precipitate: Pb(CH₃COO)₂ + H₂S → PbS + 2CH₃COOH. Other gases do not produce a black precipitate.
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Q51. A solution containing chloride ions gives a white precipitate with silver trioxonitrate(V). The precipitate will be insoluble in dilute
AHNO₃ but soluble in ammonia solution
BHNO₃ and in ammonia solution
Cammonia solution but soluble in HNO₃
DHCl and in ammonia solution
Correct Answer: A
AgNO₃ + Cl⁻ → AgCl (white precipitate). AgCl is insoluble in dilute HNO₃ but dissolves in NH₃, forming the complex [Ag(NH₃)₂]⁺.
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Q52. Which of the following halogens forms a weak acid when dissolved in water?
AFluorine
BChlorine
CBromine
DIodine
Correct Answer: A
Fluorine forms HF, a weak acid due to the strong H-F bond, which resists dissociation. HCl, HBr, and HI (from Cl, Br, I) are strong acids due to weaker bonds.
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Q53. In a Daniell cell, the electrode at which oxidation occurs is made of
ACopper
BZinc
CSilver
DIron
Correct Answer: B
In a Daniell cell (Zn|Zn²⁺||Cu²⁺|Cu), the anode is zinc, where oxidation occurs: Zn → Zn²⁺ + 2e⁻. Copper is the cathode (reduction: Cu²⁺ + 2e⁻ → Cu).
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Q54. On cracking a medicinal paraffin, a gas is evolved that gives a pop sound with a lighted splint, and an oily liquid decolourizes bromine solution. The products of the cracking are
Acarbon(IV) oxide and an alkane
Bhydrogen gas and an alkane
Chydrogen gas and an alkene
Dhydrogen gas and an alkyne
Correct Answer: C
Cracking breaks large hydrocarbons into smaller ones. The gas with a pop sound is H₂ (burns explosively). The oily liquid that decolourizes bromine is an alkene (e.g., ethene, C₂H₄), indicating unsaturation.
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Q55. An example of an aromatic compound is
ACH₃—CH₃
BC₆H₆
CCH₃—OH
DC₂H₅—OH
Correct Answer: B
Benzene (C₆H₆) is an aromatic compound with a cyclic, conjugated ring structure exhibiting resonance. Others are aliphatic (ethane, methanol, ethanol).
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Q56. Terylene is synthesized from ethane-1,2-diol and benzene-1,4-dioic acid by
Aa hydration reaction
Ban addition reaction
Ca condensation reaction
Dan elimination reaction
Correct Answer: C
Terylene (polyester) is formed by condensation polymerization of ethane-1,2-diol (HOCH₂CH₂OH) and benzene-1,4-dioic acid (HOOC-C₆H₄-COOH), releasing water molecules.
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Q57. Which of the following is true concerning the properties of benzene and hexane?
ABoth undergo substitution reactions
BBoth undergo addition reactions
CBoth are solids
DBoth can decolourize bromine water
Correct Answer: A
Benzene (aromatic) undergoes electrophilic substitution (e.g., nitration), and hexane (alkane) undergoes free radical substitution (e.g., halogenation). Neither undergoes addition nor decolourizes bromine water, and both are liquids.
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Q58. The reaction of an alkene with a hydrogen halide produces
Aan alkane
Ban alkyne
Can alcohol
Da haloalkane
Correct Answer: D
Alkenes undergo electrophilic addition with hydrogen halides (e.g., HBr): C₂H₄ + HBr → C₂H₅Br (bromoethane), forming a haloalkane.
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Q59. The number of molecules of helium gas contained in 11.5g of the gas is
A1.73 × 10²³
B1.73 × 10²²
C1.73 × 10²⁴
D1.73 × 10²¹
Correct Answer: C
Molar mass of He = 4 g/mol. Moles of He = 11.5 ÷ 4 = 2.875 mol. Number of molecules = 2.875 × 6.02 × 10²³ = 17.3 × 10²³ = 1.73 × 10²⁴.
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jamb2024chemistry
Q60. Sulphur(IV)oxide can be used as a
Acoating agent
Bdehydrating agent
Crefrigerant
Ddrying agent
Correct Answer: B
Sulphur(IV) oxide (SO₂) is used as a bleaching agent and as a food preservative, but among the given options it acts as a dehydrating agent. SO₂ can absorb water in certain reactions, and concentrated H₂SO₄ produced from SO₂ is a powerful dehydrating agent. SO₂ itself is not a refrigerant or a drying agent in standard classification. Its primary industrial use is in the Contact Process to produce H₂SO₄.