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Instruction
JAMB Chemistry 2012
JAMB (UTME)
Chemistry
2012
Q6551.If the elements X and Y have atomic numbers 11 and 17 respectively, what type of bond can they form?
ADative
BCovalent
CIonic
DMetallic
Correct Answer: C
Element X (sodium, atomic number 11) is a metal, and element Y (chlorine, atomic number 17) is a non-metal. They form an ionic (electrovalent) bond, NaCl.
JAMB (UTME)
Chemistry
2012
Q6552.A hydrogen atom which has lost an electron contains
Aone proton only
Bone neutron only
Cone proton and one neutron
Done proton, one electron and one neutron
Correct Answer: A
A hydrogen atom (¹H) has 1 proton and 1 electron (no neutron). When it loses an electron, it becomes a proton (H⁺), containing only one proton.
JAMB (UTME)
Chemistry
2012
Q6553.The electronic configuration of Mg²⁺ is
A1s² 2s² 2p⁶ 3s² 3p²
B1s² 2s² 2p⁶ 3s²
C1s² 2s² 2p⁶
D1s² 2s² 2p⁴
Correct Answer: C
Magnesium (atomic number 12) has configuration 1s² 2s² 2p⁶ 3s². When it loses 2 electrons to form Mg²⁺, the configuration becomes 1s² 2s² 2p⁶ (neon configuration).
JAMB (UTME)
Chemistry
2012
Q6554.Group VII elements are
Amonoatomic
Bgood oxidizing agents
Chighly electropositive
Delectron donors
Correct Answer: B
Group VII elements (halogens) are good oxidizing agents because they have a strong tendency to gain an electron to achieve a noble gas configuration. They are not monoatomic (they exist as diatomic molecules), highly electropositive (they are electronegative), or electron donors.
JAMB (UTME)
Chemistry
2012
Q6555.Which of the following is used to study the arrangement of particles in crystal lattices?
AAlpha-particles
BBeta-particles
CGamma-rays
DX-rays
Correct Answer: D
X-rays are used in crystallography to study the arrangement of particles in crystal lattices.
JAMB (UTME)
Chemistry
2012
Q6556.I. It has a varied composition from one place to another. II. its constituents can be separated by physical means III. It contains unreactive noble gases
AI and II only
BII and III only
CI and III only
DI, II and III
Correct Answer: A
Air has a varied composition from place to place (I) and its constituents can be separated by physical means (II). The presence of noble gases (III) does not by itself prove it is a mixture.
JAMB (UTME)
Chemistry
2012
Q6557.The chemicals used to soften hard water involves the addition of
Ainsoluble sodium compounds which form soluble solutions of calcium and magnesium
Bsoluble sodium compounds which form soluble solutions of calcium and magnesium ions
Csoluble sodium compounds which form insoluble precipitates of calcium and magnesium ions
Dinsoluble precipitates of calcium and magnesium ions
Correct Answer: C
Hard water is softened by adding soluble sodium compounds (like Na₂CO₃ or NaOH) which react with dissolved calcium and magnesium ions to form insoluble precipitates (CaCO₃, Mg(OH)₂) that can be filtered out.
JAMB (UTME)
Chemistry
2012
Q6558.Chlorination of water for town supply is carried out to
Amake the water colourless
Bremove germs from the water
Cmake the water tasteful
Dremove odour from the water
Correct Answer: B
Chlorination is the addition of chlorine to water to kill harmful microorganisms (germs) and make it safe for drinking.
JAMB (UTME)
Chemistry
2012
Q6559.The solubilities of different solutes in a given solvent can be compared by
Aplotting their solubility curves on separate axes
Bplotting their solubility curves on the same axes
Cplotting some of the solubility curves on the x-axis and others on the y-axis
Dcomparing their molar masses
Correct Answer: B
To compare the solubilities of different solutes, their solubility curves should be plotted on the same axes (temperature on x-axis, solubility on y-axis).
JAMB (UTME)
Chemistry
2012
Q6560.Potassium trioxochlorate (V) has a solubility of 1.5 mol dm⁻³ at 45°C. On cooling this solution to a temperature of 20°C, the solubility was found to be 0.5 mol dm⁻³. What mass of KClO₃ was crystallized out? [K = 39, Cl = 35.5, O = 16]
A1.00g
B10.00g
C12.25g
D122.50g
Correct Answer: D
Change in solubility = 1.5 - 0.5 = 1.0 mol dm⁻³. Molar mass of KClO₃ = 39 + 35.5 + 3(16) = 39 + 35.5 + 48 = 122.5 g/mol. Mass crystallized = 1.0 mol × 122.5 g/mol = 122.50g.
JAMB (UTME)
Chemistry
2012
Q6561.Which of the following pollutants is associated with brain damage?
ACarbon (II) oxide
BRadioactive fallout
CBiodegradable waste
DSulphur (IV) oxide
Correct Answer: B
Radioactive fallout contains radioactive isotopes that can cause brain damage and other serious health effects. Carbon(II) oxide affects oxygen transport. SO₂ affects the respiratory system.
JAMB (UTME)
Chemistry
2012
Q6562.Which of the following will produce a solution with pH less than 7 at equivalent point?
AHNO₃ + NaOH
BH₂SO₄ + KOH
CHCl + Mg(OH)₂
DHNO₃ + KOH
Correct Answer: A
The pH at the equivalence point depends on the nature of the salt formed. Strong acid + strong base gives pH = 7 (neutral). Strong acid + weak base gives pH < 7. Weak acid + strong base gives pH > 7. All the options are strong acid + strong base, so pH = 7.
JAMB (UTME)
Chemistry
2012
Q6563.The number of hydroxonium ions produced by one molecule of an acid in aqueous solution is its
Abasicity
Bacid strength
CpH
Dconcentration
Correct Answer: A
Basicity of an acid is the number of replaceable hydrogen ions (H⁺) or hydroxonium ions (H₃O⁺) produced by one molecule of the acid in aqueous solution.
JAMB (UTME)
Chemistry
2012
Q6564.During a titration experiment, 0.05 moles of carbon (IV) oxide is liberated. What is the volume of gas liberated?
A22.40 dm³
B11.20 dm³
C2.24 dm³
D1.12 dm³
Correct Answer: D
At s.t.p., 1 mole of gas occupies 22.4 dm³. 0.05 moles × 22.4 dm³/mol = 1.12 dm³.
JAMB (UTME)
Chemistry
2012
Q6565.A major factor considered in selecting a suitable method for preparing a simple salt is its
ACrystalline form
BSolubility in water
CMelting point
DReactivity
Correct Answer: B
The solubility of a salt in water is a major factor in selecting its preparation method. For example, insoluble salts are prepared by precipitation, while soluble salts are prepared by titration or direct reaction.
JAMB (UTME)
Chemistry
2012
Q6566.The oxidation number of boron in NaBH₄ is
A-3
B-1
C+1
D+3
Correct Answer: D
Na is +1, H is -1. Let B be x. +1 + x + 4(-1) = 0 → 1 + x - 4 = 0 → x = +3.
JAMB (UTME)
Chemistry
2012
Q6567.2Na₂O₂(s) + 2H₂O(l) → 4NaOH(s) + O₂(g)
A2Na₂O₂(s)
BNaOH(aq)
CH₂O(l)
DO₂(g)
Correct Answer: A
In Na₂O₂, oxygen has an oxidation state of -1. In O₂, it is 0 (oxidized), and in NaOH, it is -2 (reduced). Na₂O₂ undergoes both oxidation and reduction (disproportionation). The substance oxidized is Na₂O₂.
JAMB (UTME)
Chemistry
2012
Q6568.What number of moles of Cu²⁺ will be deposited by 360 coulombs of electricity? [F = 96500 C mol⁻¹]
A5.36 × 10⁻⁴ mole
B1.87 × 10⁻³ mole
C9.35 × 10⁻⁴ mole
D3.73 × 10⁻³ mole
Correct Answer: B
Cu²⁺ + 2e⁻ → Cu. 2 moles of electrons (2 × 96500 C) deposit 1 mole of Cu. Moles of Cu = 360 / (2 × 96500) = 360 / 193000 = 1.87 × 10⁻³ mole.
JAMB (UTME)
Chemistry
2012
Q6569.A metal M displaces zinc from ZnCl₂ solution. This shows that
Aelectrons flow from zinc to M
BM is more electropositive than zinc
CM is more electronegative than zinc
Dzinc is more electropositive than M
Correct Answer: B
A metal can displace another from its salt solution if it is more electropositive (more reactive) than the other. So M is more electropositive than zinc.
Q6571.An increase in entropy can best be illustrated by
Adissolving salt in water
Bfreezing water
Ccondensation of steam
Dsolidification of a liquid
Correct Answer: A
Entropy (disorder) increases when a solid dissolves in a liquid to form a solution. Freezing, condensation, and solidification decrease entropy (increase order).
JAMB (UTME)
Chemistry
2012
Q6572.The highest rate of production of carbon (IV) oxide can be achieved using
A0.05 mol dm⁻³ HCl and 5g powdered CaCO₃
B0.05 mol dm⁻³ HCl and 5g lump CaCO₃
C0.10 mol dm⁻³ HCl and 5g powdered CaCO₃
D0.025 mol dm⁻³ HCl and 5g powdered CaCO₃
Correct Answer: C
The rate of reaction increases with higher concentration of acid and smaller particle size (larger surface area). Option C has the highest concentration (0.10 mol dm⁻³) and powdered CaCO₃.
The question is incomplete without the graph. The curve that rises fastest initially and then levels off represents the production of CO₂.
JAMB (UTME)
Chemistry
2012
Q6574.2CO(g) + O₂(g) ⇌ 2CO₂(g)
Ahigh pressure favours gas formation
Bthe reaction is in dynamic equilibrium
Cthe reaction is exothermic
Dthe process occurs with a decrease in volume
Correct Answer: D
The forward reaction converts 3 volumes of gas (2CO + O₂) to 2 volumes of gas (2CO₂). Since the forward reaction decreases volume, high pressure favours it according to Le Chatelier's principle.
JAMB (UTME)
Chemistry
2012
Q6575.A piece of filter paper moistened with lead (II) ethanoate solution turns black when the paper is dropped into a gas likely to be
Asulphur (VI) oxide
Bhydrogen sulphide
Cammonia
Dchlorine
Correct Answer: B
Lead(II) ethanoate paper turns black in the presence of hydrogen sulphide (H₂S) gas due to the formation of black lead(II) sulphide (PbS).
JAMB (UTME)
Chemistry
2012
Q6576.Which of the following gases has a characteristic pungent smell, turns red litmus paper blue and forms dense white fumes with hydrogen chloride gas?
AN₂
BN₂O
CCl₂
DNH₃
Correct Answer: D
Ammonia (NH₃) has a pungent smell, is basic (turns red litmus blue), and forms dense white fumes of ammonium chloride (NH₄Cl) with hydrogen chloride gas.
JAMB (UTME)
Chemistry
2012
Q6577.Commercial bleaching can be carried out using
Asulphur (IV) oxide and ammonia
Bhydrogen sulphide and chlorine
Cchlorine and sulphur (IV) oxide
Dammonia and chlorine
Correct Answer: C
Chlorine and sulphur(IV) oxide are both bleaching agents. Chlorine bleaches by oxidation, while SO₂ bleaches by reduction.
JAMB (UTME)
Chemistry
2012
Q6578.Mineral acids are usually added to commercial hydrogen peroxide to
Aoxidize it
Bdecompose it
Cminimize its decomposition
Dreduce it to water and oxygen
Correct Answer: C
Mineral acids (like H₂SO₄ or H₃PO₄) are added to hydrogen peroxide to stabilize it and minimize its decomposition into water and oxygen.
JAMB (UTME)
Chemistry
2012
Q6579.Which of the following compounds will burn with a brick-red colour in a non-luminous Bunsen flame?
ALiCl
BNaCl
CCaCl₂
DMgCl₂
Correct Answer: C
Calcium compounds (CaCl₂) give a brick-red colour in a non-luminous flame. Lithium gives crimson, sodium gives yellow, and magnesium gives no colour.
JAMB (UTME)
Chemistry
2012
Q6580.The purest form of iron which contains only about 0.1% carbon is
Apig iron
Bwrought iron
Ccast iron
Diron pyrite
Correct Answer: B
Wrought iron is the purest form of iron, containing about 0.1% carbon. Pig iron contains about 4% carbon, and cast iron contains 2-4% carbon.
JAMB (UTME)
Chemistry
2012
Q6581.A common characteristic between zinc and the other transition elements is the ability to
Ahave variable oxidation states
Bform complex ions
Cact as a catalyst
Dform coloured ions
Correct Answer: B
Zinc can form complex ions like [Zn(NH₃)₄]²⁺, which is a characteristic of transition metals. Zinc does not have variable oxidation states (only +2), does not act as a catalyst in the same way, and its ions are colourless (d¹⁰ configuration).
JAMB (UTME)
Chemistry
2012
Q6582.Which of the following metals is the least reactive?
APb
BSn
CHg
DAu
Correct Answer: D
Gold (Au) is the least reactive metal. It is at the bottom of the reactivity series and does not react with water, acids, or oxygen under normal conditions.
JAMB (UTME)
Chemistry
2012
Q6583.Geometric isomerism can exist in
Ahex-3-ene
Bhexane
Cprop-1-ene
D3-methyl but-1-ene
Correct Answer: A
Geometric isomerism (cis-trans) requires a C=C double bond with different groups attached to each carbon. Hex-3-ene (CH₃CH₂CH=CHCH₂CH₃) has this structure. Hexane is saturated. Prop-1-ene has two H atoms on one carbon. 3-methylbut-1-ene has two H atoms on one carbon.
JAMB (UTME)
Chemistry
2012
Q6584.Alkanals can be distinguished from alkanones by the reaction with
ASudan III stain
Bstarch iodide paper
Clithium tetrahydrodiolaminate (III)
DFehling's solution
Correct Answer: D
Fehling's solution is used to distinguish between alkanals (aldehydes) and alkanones (ketones). Alkanals give a brick-red precipitate with Fehling's solution, while alkanones do not react.
JAMB (UTME)
Chemistry
2012
Q6585.The isomers of C₃H₈O are
A1-propanol and 2-propanol
B1-propanol and 1-propanol
C2-propanol and 2-propanone
D2-propanol and 1-propanol
Correct Answer: A
C₃H₈O has two alcohol isomers: propan-1-ol (CH₃CH₂CH₂OH) and propan-2-ol (CH₃CHOHCH₃). Note: Propanone is C₃H₆O, not C₃H₈O.
JAMB (UTME)
Chemistry
2012
Q6586.Carbohydrates are large molecules with the molecular formula Cₓ(H₂O)ᵧ. In which of the following pairs is x not equal to y?
Aglucose and starch
Bmaltose and starch
Csucrose and fructose
Dmaltose and starch
Correct Answer: A
For glucose (C₆H₁₂O₆), x=6 and y=6. For starch (C₆H₁₀O₅)ₙ, x=6n and y=5n, so x ≠ y.
JAMB (UTME)
Chemistry
2012
Q6587.A compound contains 40.0% C, 6.7% H, 53.3% O. If the molecular mass of the compound is 180, its molecular formula is [C = 12, H = 1, O = 16]
ACH₂O
BC₃H₆O₃
CC₆H₆O₃
DC₆H₁₂O₆
Correct Answer: D
Moles ratio: C = 40/12 = 3.33, H = 6.7/1 = 6.7, O = 53.3/16 = 3.33. Ratio = 1:2:1. Empirical formula = CH₂O (M=30). Molecular formula = (CH₂O)ₙ where n = 180/30 = 6. So C₆H₁₂O₆.
JAMB (UTME)
Chemistry
2012
Q6588.The alkyne that will give a white precipitate with silver trioxonitrate (V) is
ACH₃CH₂C≡CCH₂CH₃
BCH₃C≡CCH₂CH₂CH₃
CCH₃CH₂CH₂CH₂C≡CH
DCH₃CH₂CH₂C≡CCH₂CH₃
Correct Answer: C
Alkynes with a terminal triple bond (R-C≡CH) react with ammoniacal silver nitrate to form a white precipitate of silver acetylide. Option C has a terminal alkyne.
JAMB (UTME)
Chemistry
2012
Q6589.The saponification of an alkanoate to produce soap and alkanol involves
Adehydration
Besterification
Chydrolysis
Doxidation
Correct Answer: C
Saponification is the hydrolysis of an ester (alkanoate) with an alkali to produce soap (carboxylate salt) and an alkanol.
JAMB (UTME)
Chemistry
2012
Q6590.2-methylpropan-2-ol is an example of a
Aprimary alkanol
Bsecondary alkanol
Ctertiary alkanol
Dquaternary alkanol
Correct Answer: C
In 2-methylpropan-2-ol, the carbon atom bonded to the -OH group is bonded to three other carbon atoms. This makes it a tertiary alcohol.
JAMB (UTME)
Chemistry
2012
Q6591.The final oxidation product of alkanol, alkanal and alkanones is
Aalkanoic acid
Balkanoyl halide
Calkanoate
Dalkanamide
Correct Answer: A
Primary alkanols and alkanals are oxidized to alkanoic acids. Alkanones are resistant to oxidation under normal conditions.
JAMB (UTME)
Chemistry
2012
Q6592.Ethanol reacts with concentrated tetraoxosulphate (VI) acid at a temperature above 170°C to form
Aethanone
Bethene
Cethyne
Dethanol
Correct Answer: B
When ethanol is heated with concentrated H₂SO₄ at above 170°C, it undergoes dehydration to form ethene (ethylene).
JAMB (UTME)
Chemistry
2012
Q6593.An example of oxidation-reduction enzyme is
Aamylase
Bprotease
Clipase
Ddehydrogenase
Correct Answer: D
Dehydrogenase is an oxidation-reduction enzyme that catalyses the removal of hydrogen from a substrate. Amylase, protease, and lipase are hydrolytic enzymes.
Instruction
JAMB Chemistry 2013
JAMB (UTME)
Chemistry
2013
Q6594.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
2013
Q6595.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 constituent 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
2013
Q6596.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
2013
Q6597.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
2013
Q6598.200cm³ 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
2013
Q6599.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
2013
Q6600.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.