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 8601–8650 of 10710 questions
Instruction
JAMB Chemistry 1998
JAMB (UTME)
Chemistry
1998
Q8601.A common characteristic shared by iron and aluminium is that both
Aare extracted by reduction methods
Bform only basic oxides
Cshow oxidation states of +2 and +3
Dform soluble hydroxides
Correct Answer: C
Both iron and aluminium show oxidation states of +2 and +3. (Note: Aluminium is mainly +3, iron is +2 and +3. This is a weak answer, but the best among the options).
JAMB (UTME)
Chemistry
1998
Q8602.The IUPAC nomenclature for the compound above is
A4-methylpentan-3-ol
B2-methylpentan-3-ol
C3-methylpentan-3-ol
D1,1-dimethylbutan-2-ol
Correct Answer: B
The structure is CH₃-CH(CH₃)-CH(OH)-CH₂-CH₃. The longest chain has 5 carbons (pentanol). The -OH is at position 3, and the methyl group is at position 2. The correct name is 2-methylpentan-3-ol.
JAMB (UTME)
Chemistry
1998
Q8603.Dehydration of CH₃CH₂CH₂CH₂OH gives
ACH₂=CH-CH₂-CH₃
BCH₃CH=CH-CH₂-CH₃
CCH₃CH₂CH=CH₂
DCH₃C≡C-CH₃
Correct Answer: A
Dehydration of butan-1-ol (CH₃CH₂CH₂CH₂OH) gives but-1-ene (CH₂=CH-CH₂-CH₃) as the major product.
JAMB (UTME)
Chemistry
1998
Q8604.nCH₂=CH₂ → (initiator) → (-CH₂-CH₂-)ₙ
Arubber
Bpolythene
Cpolystyrene
Dbutane
Correct Answer: B
The polymerization of ethene (CH₂=CH₂) produces polythene.
JAMB (UTME)
Chemistry
1998
Q8605.One mole of a hydrocarbon contains 6 g of hydrogen. If the molecular weight is 54, the hydrocarbon is an
Aalkanone
Balkane
Calkene
Dalkyne
Correct Answer: D
Mass of carbon = 54 - 6 = 48 g. Moles of C = 48/12 = 4. Moles of H = 6/1 = 6. Empirical formula = C₄H₆. Molecular formula = C₄H₆. This is an alkyne (butyne).
JAMB (UTME)
Chemistry
1998
Q8606.The products obtained when a pure hydrocarbon is burnt in excess oxygen are
Acarbon and hydrogen
Bcarbon and water
Ccarbon (II) oxide and hydrogen
Dcarbon (IV) oxide and water
Correct Answer: D
Complete combustion of a hydrocarbon in excess oxygen produces carbon dioxide (CO₂) and water (H₂O).
JAMB (UTME)
Chemistry
1998
Q8607.How many structural isomers can be drawn for the non-cyclic alkanol with molecular formula C₄H₁₀O?
A1
B2
C3
D4
Correct Answer: D
C₄H₁₀O has four alcohol isomers: butan-1-ol, butan-2-ol, 2-methylpropan-1-ol, and 2-methylpropan-2-ol.
JAMB (UTME)
Chemistry
1998
Q8608.On cracking medicinal paraffin, a gas is evolved which gives a pop sound with a lighted splinter and an oily liquid which decolorizes bromine solution is also obtained. The products of the cracking are
Acarbon (IV) oxide and alkyne
Bcarbon (II) oxide and alkane
Chydrogen gas and alkene
Dhydrogen gas and alkane
Correct Answer: C
The gas that gives a pop sound is hydrogen. The oily liquid that decolorizes bromine water is an alkene.
JAMB (UTME)
Chemistry
1998
Q8609.An example of an aromatic compound is
AC₆H₁₂OH
BC₆H₁₂Cl
CC₆H₅OH
DC₆H₁₄
Correct Answer: C
C₆H₅OH (phenol) is an aromatic compound containing a benzene ring.
JAMB (UTME)
Chemistry
1998
Q8610.Terylene is synthesized from ethane-1,2-diol and benzene-1,4-dicarboxylic acid by
Aaddition reaction
Bcondensation reaction
Celimination reaction
Dsubstitution reaction
Correct Answer: B
Terylene is a polyester formed by condensation polymerization, with the elimination of water.
JAMB (UTME)
Chemistry
1998
Q8611.Which of the following is true concerning the properties of benzene and hexane?
ABoth undergo substitution reaction
BBoth undergo addition reaction
CBoth are solids
DBoth can decolorize bromine water
Correct Answer: A
Both benzene and hexane undergo substitution reactions. Benzene undergoes electrophilic substitution, and hexane undergoes free radical substitution.
JAMB (UTME)
Chemistry
1998
Q8612.Sucrose is made up of
Aglucose and glucose
Bglucose and fructose
Cfructose and fructose
Dgalactose and glucose
Correct Answer: B
Sucrose is a disaccharide composed of one glucose unit and one fructose unit.
Instruction
JAMB Chemistry 1999
JAMB (UTME)
Chemistry
1999
Q8613.25 cm³ of a gas X contains Z molecules at 15°C and 75 mm Hg. How many molecules will 25 cm³ of another gas Y contain at the same temperature and pressure?
A2Y
B2Z
CY
DZ
Correct Answer: D
According to Avogadro's law, equal volumes of all gases at the same temperature and pressure contain the same number of molecules. So 25 cm³ of gas Y will contain Z molecules.
JAMB (UTME)
Chemistry
1999
Q8614.What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?
A72.0g
B36.0g
C16.0g
D8.0g
Correct Answer: A
2H₂ + O₂ → 2H₂O. Moles of H₂ = 8.0/2 = 4 mol. Moles of H₂O = 4 mol. Mass of H₂O = 4 × 18 = 72.0 g.
JAMB (UTME)
Chemistry
1999
Q8615.How long does it take all the solid to melt?
A6.0 mins
B3.0 mins
C2.5 mins
D1.0 min
Correct Answer: C
From the heating curve, the solid melts during the first horizontal portion (from 0 to 2.5 mins).
JAMB (UTME)
Chemistry
1999
Q8616.If the gas is cooled, at what temperature will it start to condense?
A175°C
B250°C
C125°C
D150°C
Correct Answer: D
From the heating curve, the gas starts to condense at the second horizontal portion, which is at 150°C.
JAMB (UTME)
Chemistry
1999
Q8617.Four elements W, X, Y and Z have atomic numbers 2, 6, 16 and 20 respectively. Which of these elements is a metal?
AX
BZ
CW
DY
Correct Answer: B
Atomic number 20 is calcium (Ca), which is a metal. W (2) is helium, X (6) is carbon, Y (16) is sulphur.
JAMB (UTME)
Chemistry
1999
Q8618.The diagram above represents the formation of
Aa metallic bond
Ba covalent bond
Can electrovalent bond
Da coordinate covalent bond
Correct Answer: C
The diagram shows the transfer of electrons from a metal atom to a non-metal atom, forming ions. This is an electrovalent (ionic) bond.
JAMB (UTME)
Chemistry
1999
Q8619.An element X with relative atomic mass 16.2 contains two isotopes ¹⁶X with relative abundance of 90% and ᵐX with relative abundance of 10%. The value of m is
A14
B12
C18
D16
Correct Answer: C
(90/100 × 16) + (10/100 × m) = 16.2. 14.4 + 0.1m = 16.2. 0.1m = 1.8. m = 18.
JAMB (UTME)
Chemistry
1999
Q8620.Cancerous growths are cured by exposure to
Ax-rays
Bbeta-rays
Calpha-rays
Dgamma-rays
Correct Answer: D
Gamma rays are high-energy radiation used in radiotherapy to destroy cancerous cells.
JAMB (UTME)
Chemistry
1999
Q8621.Which of the following statements is correct about the average kinetic energy of the molecules of a gas?
AIt increases with increase in pressure
BIt increases with increase in temperature
CIt increases with increase in volume
DIt increases at constant pressure
Correct Answer: B
The average kinetic energy of gas molecules is directly proportional to the absolute temperature.
JAMB (UTME)
Chemistry
1999
Q8622.Millikan's contribution to the development of atomic theory is the determination of
Apositive rays
Bcathode rays
Ccharge to mass ratio
Dcharge on electron
Correct Answer: D
Millikan's oil drop experiment determined the charge on an electron.
JAMB (UTME)
Chemistry
1999
Q8623.A particle that contains 9 protons, 10 neutrons and 10 electrons is
Apositive ion
Bneutral atom of a metal
Cneutral atom of a non-metal
Dnegative ion
Correct Answer: D
The particle has 9 protons and 10 electrons, so it has a net charge of -1. It is a negative ion (F⁻).
JAMB (UTME)
Chemistry
1999
Q8624.An oxide XO₂ has a vapour density of 32. What is the atomic mass of X?
A20
B32
C14
D12
Correct Answer: B
Molar mass = 2 × vapour density = 2 × 32 = 64 g/mol. X + 2(16) = 64. X = 64 - 32 = 32.
JAMB (UTME)
Chemistry
1999
Q8625.The chemical used for coagulation in water purification is
Acopper tetraoxosulphate (VI)
Bsodium tetraoxosulphate (VI)
Caluminium tetraoxosulphate (VI)
Dcalcium tetraoxosulphate (VI)
Correct Answer: C
Aluminium tetraoxosulphate(VI) (alum, Al₂(SO₄)₃) is used as a coagulant in water purification.
JAMB (UTME)
Chemistry
1999
Q8626.Environmental pollution is worsened by the release from automobile exhausts of
Aheavy metals
Bwater vapour
Csmoke
Dsteam
Correct Answer: C
Automobile exhausts release smoke (particulate matter), which is a major air pollutant.
JAMB (UTME)
Chemistry
1999
Q8627.Phosphorus is stored under water to prevent it from
Aburning
Bmelting
Csubliming
Ddissolving
Correct Answer: A
White phosphorus is highly reactive and spontaneously flammable in air. It is stored under water to prevent it from burning.
JAMB (UTME)
Chemistry
1999
Q8628.Pure solvents are obtained by
Aevaporation
Bextraction
Ccondensation
Ddistillation
Correct Answer: D
Distillation is used to obtain pure solvents from solutions.
JAMB (UTME)
Chemistry
1999
Q8629.The diagram above is the solubility curve of a solute. What is the solubility of the solute at 75°C?
A75°C
B100°C
C90°C
D82°C
Correct Answer: D
From the solubility curve, at 75°C, the solubility is approximately 82 g/100g water.
JAMB (UTME)
Chemistry
1999
Q8630.If 1 dm³ of a saturated solution of L at 60°C is cooled to 25°C, what amount in mole will separate?
A0.25
B0.50
C0.75
D1.00
Correct Answer: B
From the graph, solubility at 60°C = 5.0 mol dm⁻³, at 25°C = 4.5 mol dm⁻³. Amount separated = 5.0 - 4.5 = 0.5 mol.
JAMB (UTME)
Chemistry
1999
Q8631.Deliquescent substances are used for
Adrying
Bmelting
Cwetting
Dcooling
Correct Answer: A
Deliquescent substances (like CaCl₂) absorb moisture from the air and are used as drying agents.
JAMB (UTME)
Chemistry
1999
Q8632.What is the decrease in volume of air when pyrogallol is shaken with 30.00 cm³ of air?
A0.63 cm³
B0.06 cm³
C15.00 cm³
D6.30 cm³
Correct Answer: D
Air contains about 21% oxygen. Pyrogallol absorbs oxygen. Volume decrease = 21% of 30.00 = 6.30 cm³.
JAMB (UTME)
Chemistry
1999
Q8633.The pollution from petroleum spillage in rivers and lakes can best be dispersed by
Apassing of ships through the area
Bpouring detergents
Cpouring organic solvents
Devaporation
Correct Answer: B
Spraying with detergents helps to break up the oil slick into small droplets (dispersion).