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Instruction
JAMB Chemistry 2011
JAMB (UTME)
Chemistry
2011
Q6501.An isotope has an atomic number of 15 and a mass number of 31. The number of protons it contain is
A16
B15
C46
D31
Correct Answer: B
The atomic number is equal to the number of protons. Therefore, the number of protons is 15.
JAMB (UTME)
Chemistry
2011
Q6502.The molecular lattice of iodine is held together by
Adative bond
Bmetallic bond
Chydrogen bond
Dvan der Waal's forces
Correct Answer: D
Iodine is a molecular solid. Its molecules are held together by weak van der Waals forces. Within each molecule, the atoms are held by covalent bonds.
JAMB (UTME)
Chemistry
2011
Q6503.The arrangement of particles in crystal lattices can be studied using
AX-rays
Bγ-rays
Cα-rays
Dβ-rays
Correct Answer: A
X-ray crystallography is used to study the arrangement of particles (atoms, ions, molecules) in crystal lattices.
JAMB (UTME)
Chemistry
2011
Q6504.From the diagram above, find the amount of solute deposited when 200cm³ of the solution is cooled from 55°C to 40°C
A0.10 mole
B0.20 mole
C0.01 mole
D0.02 mole
Correct Answer: B
From the graph, solubility at 55°C = 6 moles/L, solubility at 40°C = 5 moles/L. Change in solubility = 1 mole/L. For 200 cm³ = 0.2 L, amount deposited = 1 × 0.2 = 0.20 mole.
JAMB (UTME)
Chemistry
2011
Q6505.The importance of sodium aluminate (III) in the treatment of water is to
Acause coagulation
Bneutralize acidity
Cprevent goitre and tooth decay
Dkill germs
Correct Answer: A
Sodium aluminate (III) (NaAlO₂) is used in water treatment to cause coagulation — it helps fine particles clump together so they can be filtered out.
JAMB (UTME)
Chemistry
2011
Q6506.What type of bond exists between an element X with atomic number 12 and Y with atomic number 17?
AElectrovalent
BMetallic
CCovalent
DDative
Correct Answer: A
Element X (Mg, atomic number 12) is a metal and element Y (Cl, atomic number 17) is a non-metal. They form an ionic (electrovalent) bond, MgCl₂.
JAMB (UTME)
Chemistry
2011
Q6507.Hardness of water is mainly due to the presence of
Acalcium hydroxide or magnesium hydroxide
Bcalcium trioxocarbonate (IV) or calcium tetraoxosulphate (VI)
Csodium hydroxide or magnesium Hydroxide
Dcalcium chloride or sodium chloride salts
Correct Answer: B
Hardness of water is mainly due to the presence of dissolved calcium and magnesium salts — specifically calcium trioxocarbonate (CaCO₃), calcium tetraoxosulphate (CaSO₄), and their magnesium counterparts.
JAMB (UTME)
Chemistry
2011
Q6508.A suitable solvent for iodine and naphthalene is
Acarbon (IV) sulphide
Bethanol
Cwater
Dbenzene
Correct Answer: D
Benzene is a non-polar solvent that can dissolve both iodine and naphthalene (both non-polar). Water is polar. Ethanol is polar. Carbon (IV) sulphide (CS₂) is also non-polar but is less commonly used.
JAMB (UTME)
Chemistry
2011
Q6509.Which of the following noble gases is commonly found in the atmosphere?
AXenon
BArgon
CHelium
DKrypton
Correct Answer: B
Argon is the most abundant noble gas in the atmosphere (about 0.93% by volume). Helium, xenon, and krypton are present in trace amounts.
JAMB (UTME)
Chemistry
2011
Q6510.N₂O₄(g) ⇌ 2NO₂(g) ΔH = +ve. In the reaction above, an increase in temperature will
Aincrease the value of the equilibrium constant
Bdecrease the value of the equilibrium constant
Cincrease the reactant production
Dshift the equilibrium to the left
Correct Answer: A
The reaction is endothermic (ΔH positive). According to Le Chatelier's principle, increasing the temperature favours the endothermic (forward) reaction, increasing the equilibrium constant K.
CH₃COO⁻ is the conjugate base of the acid CH₃COOH. The acid donates a proton (H⁺) to form its conjugate base.
JAMB (UTME)
Chemistry
2011
Q6512.How many cations will be produced from a solution of potassium aluminium tetraoxosulphate (VI)?
A3
B4
C1
D2
Correct Answer: D
Potassium aluminium tetraoxosulphate(VI) is KAl(SO₄)₂. In solution, it dissociates into K⁺ and Al³⁺ cations, and SO₄²⁻ anions. So, 2 cations are produced.
JAMB (UTME)
Chemistry
2011
Q6513.Which of the following is NOT an alkali?
ANH₃
BMg(OH)₂
CCa(OH)₂
DNaOH
Correct Answer: B
Mg(OH)₂ (magnesium hydroxide) is a weak base but not an alkali. Alkalis are bases that are soluble in water. Mg(OH)₂ is only sparingly soluble. NH₃ (ammonia solution), Ca(OH)₂ (limewater), and NaOH are all soluble bases (alkalis).
JAMB (UTME)
Chemistry
2011
Q6514.An effect of thermal pollution on water bodies is that the
Avolume of water reduces
Bvolume of chemical waste increase
Clevel of oxides of nitrogen increase
Dlevel of oxygen reduces
Correct Answer: D
Thermal pollution (release of heated water) reduces the solubility of oxygen in water, lowering the dissolved oxygen level. This can harm aquatic life.
JAMB (UTME)
Chemistry
2011
Q6515.Which of the following is a deliquescent compound?
ANaCl
BCaCl₂
CCuO
DNa₂CO₃
Correct Answer: B
Deliquescent compounds absorb moisture from the air and dissolve in it to form a solution. Calcium chloride (CaCl₂) is deliquescent. NaCl is not. CuO is insoluble. Na₂CO₃ is efflorescent.
JAMB (UTME)
Chemistry
2011
Q6516.A chemical reaction in which the hydration energy is greater than the lattice energy is referred to as
Aa spontaneous reaction
Ban endothermic reaction
Can exothermic reaction
Da reversible reaction
Correct Answer: C
When hydration energy is greater than lattice energy, the dissolution process releases heat, making it exothermic. If lattice energy is greater, it is endothermic.
JAMB (UTME)
Chemistry
2011
Q6517.The function of zinc electrode in a galvanic cell is that it
Aundergoes reduction
Bserves as the positive electrode
Cproduces electrons
Duses up electrons
Correct Answer: C
In a galvanic cell, the more reactive metal (zinc) acts as the anode. It undergoes oxidation (loses electrons) and produces electrons that flow through the external circuit.
JAMB (UTME)
Chemistry
2011
Q6518.CH₄(g) + Cl₂(g) → CH₃Cl(s) + HCl(g)
Acatalyst
Btemperature
Cconcentration
Dlight
Correct Answer: D
The reaction between methane and chlorine is a free radical substitution reaction that is initiated by ultraviolet light. Light is the major factor influencing the rate.
JAMB (UTME)
Chemistry
2011
Q6519.The condition required for corrosion to take place is the presence of
Awater and carbon (IV) oxide
Bwater, carbon (IV) oxide and oxygen
Coxygen and carbon (IV) oxide
Dwater and oxygen
Correct Answer: D
Rusting of iron requires the presence of both water and oxygen. Carbon (IV) oxide can accelerate the process but is not essential.
JAMB (UTME)
Chemistry
2011
Q6520.In the diagram above, X is the
Aenthalpy
Benthalpy change
Cactivation energy
Dactivated complex
Correct Answer: B
X represents the enthalpy change (ΔH) of the reaction — the difference in energy between the reactants and products.
JAMB (UTME)
Chemistry
2011
Q6521.The diagram below best illustrates the effect of decrease in
Apressure on the rate of reaction
Btemperature on the rate of reaction
Cconcentration on the rate of reaction
Dsurface area on the rate of reaction
Correct Answer: B
The diagram (not fully visible) likely shows the effect of temperature on reaction rate. Decreasing temperature decreases the rate of reaction.
JAMB (UTME)
Chemistry
2011
Q6522.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 is highest with the highest concentration of acid (0.10 mol dm⁻³) and the smallest particle size (powdered CaCO₃), which provides the largest surface area.
JAMB (UTME)
Chemistry
2011
Q6523.From the reaction above, which of the curves represents the production of CO₂ gas as dilute HCl is added?
AL
BM
CN
DP
Correct Answer: B
The question is incomplete without the diagram. The curve that rises fastest initially and then levels off represents the production of CO₂.
JAMB (UTME)
Chemistry
2011
Q6524.2CO(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
2011
Q6525.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
2011
Q6526.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
2011
Q6527.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
2011
Q6528.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
2011
Q6529.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
2011
Q6530.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
2011
Q6531.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
2011
Q6532.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
2011
Q6533.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
2011
Q6534.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
2011
Q6535.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
2011
Q6536.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
2011
Q6537.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
2011
Q6538.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
2011
Q6539.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
2011
Q6540.2-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
2011
Q6541.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
2011
Q6542.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
2011
Q6543.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 2012
JAMB (UTME)
Chemistry
2012
Q6544.Which Question Paper Type of Chemistry is given to you?
AType Green
BType Purple
CType Red
DType Yellow
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
2012
Q6545.Which of the following methods can be used to obtain pure water from a mixture of sand, water and methanoic acid?
Aneutralization with NaOH followed by filtration
Bneutralization with NaOH followed by distillation
Cfractional distillation
Dfiltration followed by distillation
Correct Answer: D
First, filtration removes the sand (insoluble solid). The filtrate contains water and methanoic acid. To obtain pure water, distillation is used to separate water from methanoic acid based on their boiling points. Neutralization with NaOH would convert the acid to sodium methanoate, which would then need to be separated from water by distillation, but this introduces a salt. Filtration followed by distillation is the best method.
JAMB (UTME)
Chemistry
2012
Q6546.How many atoms are present in 6.0g of magnesium? [Mg = 24, NA = 6.02 × 10²³ mol⁻¹]
A1.20 × 10²²
B2.41 × 10²²
C1.51 × 10²³
D3.02 × 10²³
Correct Answer: C
Moles of Mg = 6.0/24 = 0.25 mol. Number of atoms = 0.25 × 6.02 × 10²³ = 1.505 × 10²³ ≈ 1.51 × 10²³.
JAMB (UTME)
Chemistry
2012
Q6547.50 cm³ of gas was collected over water at 10°C and 765 mm Hg. Calculate the volume of the gas at s.t.p. if the saturated vapour pressure of water at 10°C is 5mm Hg
A49.19 cm³
B48.87 cm³
C48.55 cm³
D48.23 cm³
Correct Answer: D
Using the combined gas law: (P₁V₁)/T₁ = (P₂V₂)/T₂. P₁ = 765 - 5 = 760 mm Hg (pressure of dry gas). V₁ = 50 cm³. T₁ = 10 + 273 = 283 K. P₂ = 760 mm Hg (s.t.p.). T₂ = 273 K. V₂ = (P₁V₁T₂)/(P₂T₁) = (760 × 50 × 273)/(760 × 283) = (50 × 273)/283 = 13650/283 = 48.23 cm³.
JAMB (UTME)
Chemistry
2012
Q6548.An increase in the pressure exerted on gas at a constant temperature result in
Aa decrease in the number of effective collisions
Ba decrease in volume
Can increase in the average intermolecular distance
Dan increase in volume
Correct Answer: B
According to Boyle's Law, at constant temperature, the volume of a fixed mass of gas is inversely proportional to its pressure. An increase in pressure results in a decrease in volume.
JAMB (UTME)
Chemistry
2012
Q6549.2H₂(g) + O₂(g) → 2H₂O(g)
A200 cm³
B400 cm³
C600 cm³
D700 cm³
Correct Answer: B
The reaction is 2H₂ + O₂ → 2H₂O. 300 cm³ of O₂ requires 2 × 300 = 600 cm³ of H₂. Since we have 1000 cm³ of H₂, the excess H₂ = 1000 - 600 = 400 cm³.
JAMB (UTME)
Chemistry
2012
Q6550.I. Evaporation. II. Sublimation. III. Diffusion. IV. Brownian motion.
AI and III only
BII and IV only
CI, II and III only
DI, II, III and IV
Correct Answer: D
All four phenomena provide evidence for the particulate nature of matter. Evaporation shows particles can escape from a liquid surface. Sublimation shows particles can move directly from solid to gas. Diffusion shows particles move and mix. Brownian motion shows particles are in constant random motion.