Practice with a curated collection of JAMB, WAEC, NECO, and school exam questions. Filter by subject, year, or exam type.
10,710questions available
12subjects covered
32years of exams
Showing 8651–8700 of 10710 questions
Instruction
JAMB Chemistry 1999
JAMB (UTME)
Chemistry
1999
Q8651.When chlorine is passed into water and the resulting solution exposed to sunlight, the products formed are
AChlorine gas and hydrogen
BHydrochloric acid and oxygen
CChlorine gas and oxochlorate (I) acid
DOxygen and oxochlorate (I) acid
Correct Answer: B
2Cl₂ + 2H₂O → 4HCl + O₂ in the presence of sunlight.
JAMB (UTME)
Chemistry
1999
Q8652.The pair of organic compounds that are isomers is
ABut-1-ene and but-2-ene
BEthanol and propanone
CTrichloromethane and tetrachloromethane
DBenzene and methylbenzene
Correct Answer: A
But-1-ene and but-2-ene have the same molecular formula (C₄H₈) but different structures.
JAMB (UTME)
Chemistry
1999
Q8653.C₁₂H₂₂O₁₁ + H₂SO₄ → 12C + 11H₂O + H₂SO₄
Aa reducing agent
Ba catalyst
Ca dehydrating agent
Dan oxidizing agent
Correct Answer: C
Concentrated H₂SO₄ removes water from sugar, leaving behind carbon. This is a dehydration reaction.
JAMB (UTME)
Chemistry
1999
Q8654.During the vulcanization of rubber, sulphur is added to
Alengthen the chain of rubber
Bbreak down rubber polymer
Cact as a catalyst
Dbind rubber molecules together
Correct Answer: D
Sulphur forms cross-links between rubber polymer chains, binding them together.
JAMB (UTME)
Chemistry
1999
Q8655.When sodium reacts with water, the resulting solution is
AAlkaline
BAcidic
CNeutral
DWeakly acidic
Correct Answer: A
2Na + 2H₂O → 2NaOH + H₂. The resulting solution is sodium hydroxide, which is alkaline.
JAMB (UTME)
Chemistry
1999
Q8656.The general formula for the alkanals is
ARCOOR
BRCO
CRCHO
DROH
Correct Answer: C
Alkanals (aldehydes) have the general formula RCHO.
JAMB (UTME)
Chemistry
1999
Q8657.Which of the following metals burns with a brick red flame?
ACa
BNa
CMg
DPb
Correct Answer: A
Calcium compounds give a brick-red colour to a non-luminous flame.
JAMB (UTME)
Chemistry
1999
Q8658.The gas that can best be collected by downward displacement of air is
AChlorine
BSulphur (IV) oxide
CCarbon (IV) oxide
DAmmonia
Correct Answer: A
Downward displacement of air is used for gases that are heavier than air. Chlorine is denser than air.
JAMB (UTME)
Chemistry
1999
Q8659.A trihydric alkanol is
APhenol
BGlycol
CGlycerol
DEthanol
Correct Answer: C
Glycerol (propane-1,2,3-triol) has three hydroxyl groups, so it is trihydric.
JAMB (UTME)
Chemistry
1999
Q8660.The main impurity in iron ore during the extraction of iron is
ACalcium trioxosilicate
BSilicon (IV) oxide
CSulphur (II) oxide
DCarbon (IV) oxide
Correct Answer: B
The main impurity in iron ore is silica (SiO₂), which is removed as slag.
JAMB (UTME)
Chemistry
1999
Q8661.A burning candle produces water and
Acarbon (IV) oxide
Bcarbon (II) oxide
Coxygen
Dhydrogen
Correct Answer: A
Complete combustion of candle wax produces carbon dioxide and water.
JAMB (UTME)
Chemistry
1999
Q8662.The molecular formula of a compound is C₆H₁₂O₆. Its empirical formula is
ACHO
BCH₂O
CC₂H₄O₂
DC₆H₁₂O₆
Correct Answer: B
The empirical formula is the simplest whole-number ratio of atoms. C₆H₁₂O₆ simplifies to CH₂O.
Instruction
JAMB Chemistry 2000
JAMB (UTME)
Chemistry
2000
Q8663.A mixture of iodine and sulphur crystals can be separated by treatment with
Awater to filter off sulphur
Bcarbon (IV) sulphide to filter off iodine
Cethanoic acid to filter off sulphur
Dmethanol to filter off iodine
Correct Answer: B
Iodine is soluble in carbon(IV) sulphide (CS₂), while sulphur is not. Filtration can then separate the insoluble sulphur.
JAMB (UTME)
Chemistry
2000
Q8664.Sieving is a technique used to separate mixtures containing solid particles of
Asmall sizes
Blarge sizes
Cdifferent sizes
Dthe same size
Correct Answer: C
Sieving separates solid particles based on size differences.
JAMB (UTME)
Chemistry
2000
Q8665.Which of the following compounds is composed of Al, Si, O and H?
AEpsom salt
BLimestone
CClay
DUrea
Correct Answer: C
Clay is a hydrated aluminium silicate, containing Al, Si, O, and H.
JAMB (UTME)
Chemistry
2000
Q8666.50 cm³ of carbon (II) oxide was exploded with 150 cm³ of air containing 20% oxygen by volume. Which of the reactants was in excess?
ACarbon (II) oxide
BCarbon (IV) oxide
COxygen
DNitrogen
Correct Answer: C
Volume of O₂ in air = 20% × 150 = 30 cm³. The reaction is 2CO + O₂ → 2CO₂. 50 cm³ of CO requires 25 cm³ of O₂. Since 30 cm³ of O₂ is available, O₂ is in excess.
JAMB (UTME)
Chemistry
2000
Q8667.How many moles of HCl will be required to react with potassium heptaoxodichromate (VI) to produce 3 moles of chlorine?
A14
B12
C11
D10
Correct Answer: B
K₂Cr₂O₇ + 14HCl → 2KCl + 2CrCl₃ + 7H₂O + 3Cl₂. 14 moles of HCl produce 3 moles of Cl₂.
JAMB (UTME)
Chemistry
2000
Q8668.The ratio of the initial to the final pressure of a given mass of gas is 1:1.5. Calculate the final volume of the gas if the initial volume was 300 cm³ at the same temperature.
Q8670.The fundamental difference between the three states of matter is the
Ashape of their particles
Bnumber of particles in each state
Cshape of the container they occupy
Ddegree of movement of their particles
Correct Answer: D
The main difference between solids, liquids, and gases is the degree of movement of their constituent particles.
JAMB (UTME)
Chemistry
2000
Q8671.Which of the following statements is correct about the periodic table?
AElements in the same period have the same number of valence electrons
BThe valence electrons of the elements in the same period increase progressively across the period
CElements in the same group have the same number of electron shells
DThe non-metallic properties of the elements tend to decrease across each period
Correct Answer: B
Across a period, the number of valence electrons increases progressively.
JAMB (UTME)
Chemistry
2000
Q8672.The electron configuration of ₂₂X²⁺ ion is
A1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d²
B1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹
C1s² 2s² 2p⁶ 3s² 3p⁶
D1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d³
Correct Answer: C
Element X has atomic number 22 (titanium). X²⁺ has lost 2 electrons, so its configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ (argon configuration).
JAMB (UTME)
Chemistry
2000
Q8673.Which of the following types of bonding does NOT involve the formation of new substances?
AMetallic
BCovalent
CCo-ordinate
DElectrovalent
Correct Answer: A
Metallic bonding is a physical attraction between metal cations and delocalized electrons. It does not involve the formation of new chemical substances.
JAMB (UTME)
Chemistry
2000
Q8674.The knowledge of half-life can be used to
Acreate an element
Bdetect an element
Csplit an element
Dirradiate an element
Correct Answer: B
Half-life is used in radiometric dating to detect the age of an element or artifact.
JAMB (UTME)
Chemistry
2000
Q8675.The shape of CO₂, H₂O and CH₄ respectively are
Abent, linear and tetrahedral
Bbent, tetrahedral and linear
Clinear, bent and tetrahedral
Dtetrahedral, linear and bent
Correct Answer: C
CO₂ is linear, H₂O is bent (V-shaped), and CH₄ is tetrahedral.
JAMB (UTME)
Chemistry
2000
Q8676.The distance between the nuclei of chlorine atoms in a chlorine molecule is 0.914 nm. The atomic radius of chlorine atom is
A0.097 nm
B0.914 nm
C2.388 nm
D0.457 nm
Correct Answer: D
The bond length is the distance between two nuclei. Atomic radius = bond length / 2 = 0.914 / 2 = 0.457 nm.
JAMB (UTME)
Chemistry
2000
Q8677.The noble gas, argon, is used for
Aelectric arc welding
Bwelding brass
Cunderwater welding
Dsteel welding
Correct Answer: A
Argon is used as a shielding gas in electric arc welding to prevent oxidation of the hot metal.
JAMB (UTME)
Chemistry
2000
Q8678.A side effect of soft water is that
Ait gives offensive taste
Bexcess calcium is precipitated
Cit attacks lead contained in pipes
Dit encourages the growth of bacteria
Correct Answer: C
Soft water is acidic and can dissolve lead from pipes, leading to lead poisoning.
JAMB (UTME)
Chemistry
2000
Q8679.Water molecules can be ligands especially when they are bonded to
Aalkaline earth metals
Balkali metals
Ctransition metals
Dgroup VII elements
Correct Answer: C
Water molecules act as ligands when they coordinate to transition metal ions (e.g., [Cu(H₂O)₆]²⁺).
JAMB (UTME)
Chemistry
2000
Q8680.The air pollutant unknown in nature is
ANO
BCO
CHCHO
DDDT
Correct Answer: D
DDT (dichlorodiphenyltrichloroethane) is a synthetic pesticide that does not occur naturally in the environment.
JAMB (UTME)
Chemistry
2000
Q8681.10 dm³ of distilled water used to wash 2.0 g of a precipitate of AgCl. If the solubility product of AgCl is 2.0 × 10⁻¹⁰ mol² dm⁻⁶, what quantity of silver was lost in the process?
A2.029 × 10⁻³ mol dm⁻³
B1.414 × 10⁻³ mol dm⁻³
C2.029 × 10⁻⁵ mol dm⁻³
D1.414 × 10⁻⁵ mol dm⁻³
Correct Answer: A
Solubility (s) = √Ksp = √(2.0 × 10⁻¹⁰) = 1.414 × 10⁻⁵ mol dm⁻³. Moles lost in 10 dm³ = 1.414 × 10⁻⁴ mol. (The provided answer E is a typo).
JAMB (UTME)
Chemistry
2000
Q8682.Hydration of ions in solution is associated with
Aabsorption of heat
Breduction of heat
Cconduction of heat
Dliberation of heat
Correct Answer: D
Hydration of ions is an exothermic process that releases heat.
JAMB (UTME)
Chemistry
2000
Q8683.The diagram above is the solubility curve of solute, X. Find the amount of X deposited when 500 cm³ of solution of X is cooled from 60°C to 20°C.
A0.745 mol
B0.950 mol
C2.375 mol
D4.750 mol
Correct Answer: C
From the graph, solubility at 60°C = 5.0 mol dm⁻³, at 20°C = 3.0 mol dm⁻³. Amount deposited = (5.0 - 3.0) × 0.5 = 1.0 mol. (The provided answer C is a typo).
JAMB (UTME)
Chemistry
2000
Q8684.HCl(aq) + H₂O(l) ⇌ H₃O⁺(aq) + Cl⁻(aq)
AConjugate acid
BAcid
CConjugate base
DBase
Correct Answer: C
Cl⁻ is the conjugate base of the acid HCl.
JAMB (UTME)
Chemistry
2000
Q8685.In which order are the following salts sensitive to light?
AAgI > AgCl > AgBr
BAgCl > AgI > AgBr
CAgBr > AgCl > AgI
DAgCl > AgBr > AgI
Correct Answer: D
The order of light sensitivity of silver halides is AgCl > AgBr > AgI.
JAMB (UTME)
Chemistry
2000
Q8686.The pOH of a solution of 0.25 mol dm⁻³ of hydrochloric acid is
A12.40
B13.40
C14.40
D14.60
Correct Answer: A
HCl is a strong acid, [H⁺] = 0.25 M. pH = -log(0.25) = 0.60. pOH = 14 - 0.60 = 13.40. (The provided answer E is a typo; the correct answer is B).
JAMB (UTME)
Chemistry
2000
Q8687.MnO₄⁻ + 8H⁺ + ne⁻ → Mn²⁺ + 4H₂O. Y in the equation above represents
A2
B3
C5
D7
Correct Answer: C
In MnO₄⁻, Mn is +7. In Mn²⁺, it is +2. The change is 5 electrons. So n = 5.
JAMB (UTME)
Chemistry
2000
Q8688.In the reaction 1/2Zn²⁺(aq) + e⁻ → 1/2Zn(s), calculate the quantity of electricity required to discharge zinc.
A0.965 × 10⁴ C
B4.820 × 10⁴ C
C9.650 × 10⁴ C
D48.200 × 10⁴ C
Correct Answer: A
The reaction shows 1 mole of electrons depositing 0.5 mole of Zn. To deposit 1 mole of Zn, 2 moles of electrons are needed = 2F = 193,000 C. (The provided answer E is a typo).
JAMB (UTME)
Chemistry
2000
Q8689.Given that M is the mass of substance deposited in an electrolysis and Q the quantity of electricity consumed, then Faraday's law can be written as
AM = Z/Q
BM = Q/Z
CM = Z
DM = QZ
Correct Answer: D
Faraday's first law states that M = ZQ, where Z is the electrochemical equivalent.
JAMB (UTME)
Chemistry
2000
Q8690.0.46 g of ethanol when burned raised the temperature of 50 g water by 14.3 K. Calculate the heat of combustion of ethanol.
A+3000 kJ mol⁻¹
B+300 kJ mol⁻¹
C-300 kJ mol⁻¹
D-3000 kJ mol⁻¹
Correct Answer: A
Heat released = mcΔT = 50 × 4.2 × 14.3 = 3003 J = 3.003 kJ. Moles of ethanol = 0.46/46 = 0.01 mol. Heat of combustion = -3.003/0.01 = -300.3 kJ mol⁻¹ ≈ -300 kJ mol⁻¹. (The provided answer E is a typo; the correct answer is C).
JAMB (UTME)
Chemistry
2000
Q8691.Powdered marble reacts with hydrochloric acid solution than the granular form because the powdered form has
Amore molecules
Bmore atoms
Clarge surface area
Drelatively large mass
Correct Answer: C
Powdered marble has a larger surface area, which increases the rate of reaction.
JAMB (UTME)
Chemistry
2000
Q8692.The graph that describes a zero order reaction is
AGraph A
BGraph B
CGraph C
DGraph D
Correct Answer: B
A zero-order reaction has a constant rate independent of concentration, so the rate vs. concentration graph is a horizontal line.
JAMB (UTME)
Chemistry
2000
Q8693.For the reaction 2NO(g) + O₂(g) ⇌ 2NO₂(g); ΔH = -114 kJ mol⁻¹. A decrease in temperature will
Aincrease the quantity of N₂
Bincrease the yield of NO₂
Cdecrease the yield of NO₂
Ddecrease the quantity of O₂
Correct Answer: B
The reaction is exothermic (ΔH negative). Decreasing temperature favours the forward reaction, increasing the yield of NO₂.
JAMB (UTME)
Chemistry
2000
Q8694.For a reaction in equilibrium, the species involved in the equilibrium constant expression are
Agaseous and solid species
Bliquid and solid species
Csolid and dissolved species
Dgaseous and dissolved species
Correct Answer: D
The equilibrium constant expression includes only gaseous and dissolved (aqueous) species. Pure solids and liquids are excluded.
JAMB (UTME)
Chemistry
2000
Q8695.A phenomenon where an element exists in different forms in the same physical state is known as
Aisomerism
Bamorphism
Callotropy
Disotropy
Correct Answer: C
Allotropy is the existence of an element in two or more different forms in the same physical state.
JAMB (UTME)
Chemistry
2000
Q8696.The substance often used for vulcanization of rubber is
Achlorine
Bhydrogen peroxide
Csulphur
Dtetraoxosulphate (VI) acid
Correct Answer: C
Sulphur is used in the vulcanization of rubber.
JAMB (UTME)
Chemistry
2000
Q8697.A gas that is not associated with global warming is
ACO₂
BSO₂
CCH₄
DH₂
Correct Answer: D
Hydrogen (H₂) is not a greenhouse gas and does not contribute to global warming.
JAMB (UTME)
Chemistry
2000
Q8698.The refreshing and characteristic taste of soda water and other soft drinks is as a result of the presence in them of
Acarbon (IV) oxide
Bcarbon (II) oxide
Csoda
Dglucose
Correct Answer: A
The refreshing taste of soda water is due to dissolved carbon(IV) oxide (CO₂).
JAMB (UTME)
Chemistry
2000
Q8699.A form of carbon used for absorbing poisonous gases and purification of noble gases is
Awood charcoal
Banimal charcoal
Ccarbon fibres
Dcarbon black
Correct Answer: A
Wood charcoal (activated charcoal) is highly porous and used for absorbing poisonous gases.
JAMB (UTME)
Chemistry
2000
Q8700.Synthetic gas is a mixture of
ACH₄ and H₂O
BCH₄ and H₂
CCO₂ and H₂
DCO and H₂
Correct Answer: D
Synthetic gas (syngas) is a mixture of carbon monoxide (CO) and hydrogen (H₂).