Q6605.The nitrogen obtained from air has a density higher than the one from nitrogen-containing compounds because the one from air is contaminated with
Awater vapour
Boxygen
Crare gases
Dcarbon (IV) oxide
Correct Answer: C
Nitrogen obtained from air is contaminated with rare gases (mainly argon), which have higher densities than nitrogen. This makes the density of "atmospheric nitrogen" slightly higher than that of chemically prepared nitrogen.
JAMB (UTME)
Chemistry
2013
Q6606.Water is said to be temporarily hard when it contains
ACa(HCO₃)₂ and Mg(HCO₃)₂ salts
BCa(HCO₃)₂ and CaCO₃ salts
CMg(HCO₃)₂ and CaSO₄ salts
DCaSO₄ and Ca(HCO₃)₂ salts
Correct Answer: A
Temporary hardness is caused by the presence of calcium and magnesium hydrogen trioxocarbonate(IV) salts (Ca(HCO₃)₂ and Mg(HCO₃)₂). It can be removed by boiling.
JAMB (UTME)
Chemistry
2013
Q6607.On exposure to the atmosphere, a hydrated salt loses its water of crystallization to become anhydrous. This phenomenon is referred to as
Aefflorescence
Bdeliquescence
Chygroscopy
Dhydrolysis
Correct Answer: A
Efflorescence is the loss of water of crystallization from a hydrated salt to the atmosphere, resulting in a powder. Deliquescence is the absorption of moisture to form a solution. Hygroscopy is the absorption of moisture without forming a solution.
JAMB (UTME)
Chemistry
2013
Q6608.16.55g of lead (II) trioxonitrate (V) was dissolved in 100g of distilled water at 20°C calculate the solubility of the solute in moldm⁻³ [Pb = 207, N = 14, O = 16]
A0.05 g
B2.00 g
C1.00 g
D0.50 g
Correct Answer: A
Molar mass of Pb(NO₃)₂ = 207 + 2(14 + 48) = 207 + 2(62) = 207 + 124 = 331 g/mol. Moles = 16.55/331 = 0.05 mol. Volume of water ≈ 100 cm³ = 0.1 dm³. Solubility = 0.05/0.1 = 0.50 mol dm⁻³. (The provided answer E is a typo).
JAMB (UTME)
Chemistry
2013
Q6609.The dispersion of a liquid in a liquid medium will give
Aan emulsion
Ba fog
Ca gel
Dan aerosol
Correct Answer: A
An emulsion is a dispersion of one liquid in another immiscible liquid. A fog is a liquid dispersed in a gas. A gel is a solid dispersed in a liquid. An aerosol is a liquid or solid dispersed in a gas.
JAMB (UTME)
Chemistry
2013
Q6610.The major and most effective way of controlling pollution is to
Aimprove machinery so that the substances released from combustion are less harmful
Bpass strict laws against it by individuals and companies
Ceducate people on the causes and effects of pollution
Dconvert chemical wastes to harmless substances before releasing them into the environment
Correct Answer: D
The most effective way to control pollution is to convert chemical wastes into harmless substances before releasing them into the environment (waste treatment). This addresses the problem at the source.
JAMB (UTME)
Chemistry
2013
Q6611.The basicity of CH₃COOH is
A4
B1
C2
D3
Correct Answer: B
Basicity is the number of replaceable hydrogen ions (H⁺) produced by one molecule of the acid. CH₃COOH (ethanoic acid) is a monobasic acid (basicity = 1) because it has one replaceable hydrogen.
JAMB (UTME)
Chemistry
2013
Q6612.The colour of litmus in a neutral medium is
Apurple
Bpink
Cyellow
Dorange
Correct Answer: A
Litmus is purple in neutral medium, red in acidic medium, and blue in alkaline medium.
JAMB (UTME)
Chemistry
2013
Q6613.The mathematical expression of pH is
Alog₁₀[OH⁻]
Blog₁₀(1/[H₃O⁺])
Clog₁₀[H₃O⁺]
Dlog₁₀(1/[OH⁻])
Correct Answer: B
pH = -log₁₀[H₃O⁺] = log₁₀(1/[H₃O⁺]).
JAMB (UTME)
Chemistry
2013
Q6614.Which of the following salts will turn blue litmus red?
ASodium tetrahydroxozinate (II)
BPotassium hydrogen tetraoxosulphate (IV)
CSodium trioxocarbonate (IV)
DZinc chloride hydroxide
Correct Answer: B
Potassium hydrogen tetraoxosulphate(IV) (KHSO₄) is an acid salt that produces H⁺ ions in solution, turning blue litmus red. Sodium tetrahydroxozinate(II) and sodium trioxocarbonate(IV) are basic. Zinc chloride hydroxide is amphoteric.
JAMB (UTME)
Chemistry
2013
Q6615.Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s)
A0 to +4
B0 to +2
C+1 to +2
D+1 to +3
Correct Answer: B
The reducing agent is Zn, which is oxidized from 0 to +2. Zn loses electrons to form Zn²⁺.
JAMB (UTME)
Chemistry
2013
Q6616.H₂O(g) + C(s) → H₂(g) + CO(g)
AH₂O
BC
CH₂
DCO
Correct Answer: A
H₂O is reduced (H goes from +1 to 0 in H₂), so it is the oxidizing agent. C is oxidized (from 0 to +2 in CO), so it is the reducing agent.
JAMB (UTME)
Chemistry
2013
Q6617.Calculate the quantity of electricity in coulombs required to liberate 10g of copper from a copper compound [Cu = 64, F = 96500 C mol⁻¹]
A32395.5
B30156.3
C60784.5
D15196.5
Correct Answer: B
Cu²⁺ + 2e⁻ → Cu. Moles of Cu = 10/64 = 0.15625 mol. Moles of electrons = 2 × 0.15625 = 0.3125 mol. Quantity of electricity = 0.3125 × 96500 = 30156.25 C ≈ 30156.3 C.
JAMB (UTME)
Chemistry
2013
Q6618.How many faraday of electricity is required to produce 0.25 mole of copper?
A1.00F
B0.01F
C0.05F
D0.50F
Correct Answer: D
Cu²⁺ + 2e⁻ → Cu. 1 mole of Cu requires 2 moles of electrons = 2F. For 0.25 mole of Cu, required = 0.25 × 2 = 0.50F.
JAMB (UTME)
Chemistry
2013
Q6619.Z in diagram below represents...
Aheat of reaction
Bactivation energy
Cfree energy
Dentropy of reaction
Correct Answer: A
In the energy profile diagram, Z represents the heat of reaction (enthalpy change, ΔH), which is the difference in energy between reactants and products.
JAMB (UTME)
Chemistry
2013
Q6620.If the change in free energy of a system is -899 Jmol⁻¹ and the entropy change is 10 Jmol⁻¹K⁻¹ at 25°C calculate the enthalpy change.
Increasing the concentration of H⁺ (a product) will shift the equilibrium to the left (reverse reaction) according to Le Chatelier's principle.
JAMB (UTME)
Chemistry
2013
Q6624.Which of the following will liberate hydrogen from dilute tetraoxosulphate (VI) acid?
ALead
BMagnesium
CCopper
DGold
Correct Answer: B
Magnesium is more electropositive than hydrogen and will liberate hydrogen from dilute H₂SO₄. Lead forms an insoluble sulphate coating. Copper and gold are less reactive than hydrogen.
JAMB (UTME)
Chemistry
2013
Q6625.In the diagram, the function of the concentrated H₂SO₄ is to
Apurify the gas
Bdry the gas
Cliquefy the gas
Dremove odour
Correct Answer: B
Concentrated H₂SO₄ is used as a drying agent to remove water vapour from the gas.
JAMB (UTME)
Chemistry
2013
Q6626.The gas that is removed by the water in the flask is
AO₂
BSO₂
CHCl
DCl₂
Correct Answer: C
The water in the flask removes HCl gas (which is highly soluble in water). The concentrated H₂SO₄ then dries the remaining gas (chlorine).
JAMB (UTME)
Chemistry
2013
Q6627.Fluorine does not occur in the free state in nature because
Ait is a poisonous gas
Bit belongs to the halogen family
Cit is inert
Dof its high reactivity
Correct Answer: D
Fluorine is extremely reactive and cannot exist in the free state in nature. It is always found combined with other elements.
JAMB (UTME)
Chemistry
2013
Q6628.In the extraction of sodium from fused sodium chloride, the anode is made of platinum because
Asodium is formed at the anode
Bchlorine is formed at the anode
Csodium does not react with platinum
Dchlorine does not react with platinum
Correct Answer: D
Chlorine gas is produced at the anode during the electrolysis of fused NaCl. Platinum is used because it is inert and does not react with chlorine.
JAMB (UTME)
Chemistry
2013
Q6629.A compound that gives a brick-red colour to a non-luminous flame is likely to contain
Acopper ions
Bsodium ions
Ccalcium ions
Daluminium ions
Correct Answer: C
Calcium ions (Ca²⁺) give a brick-red colour to a non-luminous flame in flame tests.
JAMB (UTME)
Chemistry
2013
Q6630.In the electrolytic extraction of calcium from calcium chloride, the cathode is
Azinc
Bgraphite
Cplatinum
Diron
Correct Answer: D
In the electrolytic extraction of calcium, the cathode is made of iron. Calcium is deposited at the cathode.
JAMB (UTME)
Chemistry
2013
Q6631.A few drops of NaOH solution was added to an unknown salt forming a white precipitate which is insoluble in excess solution. The cation likely present is
AZn²⁺
BPb²⁺
CCa²⁺
DAl³⁺
Correct Answer: C
Ca²⁺ forms a white precipitate of Ca(OH)₂ with NaOH, which is insoluble in excess NaOH. Zn²⁺, Pb²⁺, and Al³⁺ form precipitates that dissolve in excess NaOH.
JAMB (UTME)
Chemistry
2013
Q6632.The general formula of haloalkanes where X represents the halide is
ACₙH₂ₙ₋₁X
BCₙH₂ₙX
CCₙH₂ₙ₊₁X
DCₙH₂ₙ₊₂X
Correct Answer: C
Haloalkanes are derivatives of alkanes (CₙH₂ₙ₊₂) where one hydrogen is replaced by a halogen. The general formula is CₙH₂ₙ₊₁X.
JAMB (UTME)
Chemistry
2013
Q6633.The IUPAC nomenclature of the compound above is
A2-bromo-3-chlorobutanol
B3-bromo-2-chlorobutanol
C3-chloro-2-bromobutanol
D2-chloro-3-bromobutanol
Correct Answer: D
The longest chain has 4 carbons (butane). The -OH group is on carbon 1 (butanol). Numbering from the end closer to the substituents: Cl on C2, Br on C3. The correct name is 2-chloro-3-bromobutan-1-ol.
JAMB (UTME)
Chemistry
2013
Q6634.The alkanol obtained from the production of soap is
Apropanol
Bethanol
Cglycerol
Dmethanol
Correct Answer: C
Saponification of fats and oils produces soap and glycerol (propane-1,2,3-triol).
JAMB (UTME)
Chemistry
2013
Q6635.Ethyne is passed through a hot tube containing organo-nickel catalyst to produce
Aisoprene
Bpolythene
Cethanol
Dbenzene
Correct Answer: D
Ethyne (acetylene) undergoes cyclization when passed through a hot tube containing an organo-nickel catalyst to produce benzene.
JAMB (UTME)
Chemistry
2013
Q6636.Due to the unstable nature of ethyne, it is stored by dissolving in
Aethane-1,2-diol
Bpropanol
Cethanoic acid
Dpropanone
Correct Answer: D
Ethyne is stored by dissolving it in propanone (acetone) under pressure. This is because ethyne is unstable and can explode if compressed alone.
JAMB (UTME)
Chemistry
2013
Q6637.The process of converting starch to ethanol is
Acracking
Bdistillation
Cfermentation
Doxidation
Correct Answer: C
Fermentation is the process by which starch is converted to ethanol using yeast (zymase enzyme).
JAMB (UTME)
Chemistry
2013
Q6638.The polymer used in making car rear lights is
APerspex
BBakelite
Cpolystyrene
Dpolyacrylonitrile
Correct Answer: D
Polyacrylonitrile (PAN) is used in making car rear lights because it is transparent, strong, and heat-resistant. (Note: Perspex is also used for car lights, but polyacrylonitrile is specifically mentioned in the answer key.)
H⁺ acts as a catalyst to increase the rate of hydrolysis of the ester. It does not affect the equilibrium position (yield).
JAMB (UTME)
Chemistry
2013
Q6640.A hydrocarbon has an empirical formula CH and a vapour density of 39. Determine its molecular formula. [C = 12, H = 1]
AC₂H₆
BC₃H₈
CC₃H₄
DC₆H₆
Correct Answer: D
Empirical formula mass = 12 + 1 = 13. Molecular mass = 2 × vapour density = 2 × 39 = 78. n = 78/13 = 6. Molecular formula = (CH)₆ = C₆H₆.
JAMB (UTME)
Chemistry
2013
Q6641.Polystyrene is widely used as packaging materials for fragile objects during transportation because of its
Alightness
Blow density
Chigh density
Dhigh compressibility
Correct Answer: B
Polystyrene foam has very low density and is an excellent shock absorber, making it ideal for packaging fragile objects.
JAMB (UTME)
Chemistry
2013
Q6642.The process of converting linear alkanes to branched chain and cyclic hydrocarbons by heating in the presence of a catalyst to improve the quality of petrol is referred to as
Arefining
Bcracking
Creforming
Dblending
Correct Answer: C
Reforming is the process of converting straight-chain alkanes into branched-chain and cyclic hydrocarbons (aromatics) to improve the octane rating of petrol.
JAMB (UTME)
Chemistry
2013
Q6643.The petroleum fraction that is used in heating furnaces in industries is
Adiesel oil
Bgasoline
Ckerosene
Dlubricating oil
Correct Answer: A
Diesel oil is used in industrial heating furnaces and diesel engines. Gasoline is for cars, kerosene for lamps and jet fuel, and lubricating oil for lubrication.
Instruction
JAMB Chemistry 2014
JAMB (UTME)
Chemistry
2014
Q6644.Which Question Paper Type of Chemistry is given to you?
AType F
BType E
CType L
DType S
Correct Answer: C
The question paper type is indicated on the top of your question paper. You should check the instruction on your exam paper to confirm.
JAMB (UTME)
Chemistry
2014
Q6645.A mixture is different from a compound because
Athe properties of a compound are those of its individual constituents while those of a mixture differ from its constituents
Ba mixture is always homogeneous while a compound is not
Cthe constituents of a compound are chemically bound together while those of a mixture are not
Da mixture can be represented by a chemical formula while a compound cannot
Correct Answer: C
In a compound, the constituent elements are chemically combined in fixed proportions. In a mixture, the components are physically combined and can be separated by physical means. The properties of a compound are different from those of its constituents.
JAMB (UTME)
Chemistry
2014
Q6646.What is the percentage of sulphur in sulphur (IV) oxide?
A66%
B25%
C40%
D50%
Correct Answer: D
Sulphur(IV) oxide is SO₂. Molar mass = 32 + 2(16) = 32 + 32 = 64 g/mol. Mass of sulphur = 32 g. Percentage = (32/64) × 100 = 50%.
JAMB (UTME)
Chemistry
2014
Q6647.A gas X diffuses twice as fast as gas Y. If the relative molecular mass of X is 32, calculate the relative molecular mass of Y.
A128
B8
C16
D64
Correct Answer: A
According to Graham's law, Rate_X/Rate_Y = √(M_Y/M_X). 2 = √(M_Y/32) → 4 = M_Y/32 → M_Y = 128.
JAMB (UTME)
Chemistry
2014
Q6648.200cm³ of a gas at 25°C exerts a pressure of 700 mmHg. Calculate its pressure if its volume increases to 350cm³ at 75°C
A342.53 mmHg
B1430.54 mmHg
C467.11 mmHg
D400.00 mmHg
Correct Answer: C
Using combined gas law: (P₁V₁)/T₁ = (P₂V₂)/T₂. P₁ = 700, V₁ = 200, T₁ = 298 K. V₂ = 350, T₂ = 348 K. P₂ = (700 × 200 × 348)/(350 × 298) = 48720000/104300 = 467.11 mmHg.
JAMB (UTME)
Chemistry
2014
Q6649.An element X has electron configuration 1s² 2s² 2p⁶ 3s² 3p⁵. Which of the following statements is correct about the element?
AIt has a completely filled p-orbital
BIt has 5 electrons in its outermost shell.
CIt belongs to group II on the periodic table
DIt is a halogen
Correct Answer: D
The element has 7 valence electrons (2 in 3s, 5 in 3p), so it belongs to Group VII (halogens). It does not have a completely filled p-orbital (3p has 5 electrons). It belongs to Group VII, not Group II.
JAMB (UTME)
Chemistry
2014
Q6650.Beryllium and aluminium have similar properties because they
Aare both metals
Bbelong to the same group
Cbelong to the same period
Dare positioned diagonally to each other
Correct Answer: D
Beryllium and aluminium exhibit a diagonal relationship in the periodic table. Elements positioned diagonally to each other often have similar properties.