Skip to content

Chemistry past questions: JAMB UTME 2023

82 objective questions, with answers. Free to read and practise.

Sit this paper

82 questions, one at a time, marked as you go or at the end. No account needed.

  1. 1.
    A blue litmus paper turns red when dipped into a solution. What does this indicate about the solution?
    1. A.The solution is basic
    2. B.The solution is neutral
    3. C.The solution is acidic
    4. D.The litmus paper is faulty
    Show answer

    Answer: C The solution is acidic

  2. 2.
    A gas occupies a volume of 1.5 liters at a pressure of 2 atmospheres. If the pressure is increased to 4 atmospheres while the temperature remains constant, what will be the new volume of the gas?
    1. A.6 liters
    2. B.1.5 liters
    3. C.0.75 liters
    4. D.3 liters
    Show answer

    Answer: C 0.75 liters

  3. 3.
    According to the kinetic theory of gases, the pressure exerted by a gas is due to
    1. A.The vibrations of gas particles
    2. B.The weight of the gas particles
    3. C.The attractive forces between gas particles
    4. D.The collisions of gas particles with the container walls
    Show answer

    Answer: D The collisions of gas particles with the container walls

  4. 4.
    An element has an atomic number of 8 and a mass number of 16. How many neutrons does this element have?
    1. A.24
    2. B.16
    3. C.8
    4. D.32
    Show answer

    Answer: C 8

  5. 5.
    At 2.0 atm pressure, the volume of a gas is 4.0 L. If the pressure is reduced to 1.0 atm while keeping the temperature constant, what will be the new volume of the gas?
    1. A.2.0 L
    2. B.6.0 L
    3. C.8.0 L
    4. D.4.0 L
    Show answer

    Answer: C 8.0 L

  6. 6.
    At room temperature and standard pressure, chlorine gas is in which state of matter?
    1. A.Plasma
    2. B.Solid
    3. C.Liquid
    4. D.Gas
    Show answer

    Answer: D Gas

  7. 7.
    Balance the following redox reaction: Fe \(_2\) O \(_3\) + CO → Fe + CO \(_2\)
    1. A.Fe \(_2\) O \(_3\) + CO → 2Fe + 2CO \(_2\)
    2. B.2Fe \(_2\) O \(_3\) + 3CO → 4Fe + 3CO \(_2\)
    3. C.Fe \(_2\) O \(_3\) + 2CO → 2Fe + 2CO \(_2\)
    4. D.Fe \(_2\) O \(_3\) + 3CO → 2Fe + 3CO \(_2\)
    Show answer

    Answer: D Fe \(_2\) O \(_3\) + 3CO → 2Fe + 3CO \(_2\)

  8. 8.
    Benzene can be converted to its derivative toluene by the addition of a methyl group. The reaction is an example of
    1. A.Nucleophilic substitution
    2. B.Elimination reaction
    3. C.Electrophilic substitution
    4. D.Addition reaction
    Show answer

    Answer: C Electrophilic substitution

  9. 9.
    Chlorine gas is commonly used in the production of which of the following industrial compounds?
    1. A.Chlorofluorocarbons (CFCs)
    2. B.Methane
    3. C.Ammonia
    4. D.Ethanol
    Show answer

    Answer: A Chlorofluorocarbons (CFCs)

  10. 10.
    How many pi ( \(\pi\) ) bonds are there in an alkene with six carbon atoms?
    1. A.1
    2. B.6
    3. C.5
    4. D.3
    Show answer

    Answer: A 1

  11. 11.
    Identify the reducing agent in the following reaction: Zn + CuSO \(_4\) → ZnSO \(_4\) + Cu
    1. A.Cu
    2. B.Zn
    3. C.ZnSO \(_4\)
    4. D.CuSO \(_4\)
    Show answer

    Answer: B Zn

  12. 12.
    If gas A has a molar mass of 32 g/mol and gas B has a molar mass of 64 g/mol, what is the ratio of their diffusion rates?
    1. A.2:1
    2. B.1:2
    3. C.1:1
    4. D.1:4
    Show answer

    Answer: A 2:1

  13. 13.
    Isotopes of an element have
    1. A.The same number of protons but different numbers of neutrons
    2. B.The same number of neutrons and electrons
    3. C.The same number of protons and neutrons
    4. D.The same number of protons and electrons
    Show answer

    Answer: A The same number of protons but different numbers of neutrons

  14. 14.
    Sodium reacts vigorously with water to produce
    1. A.Sodium chloride (NaCl) and oxygen gas (O2)
    2. B.Sodium nitrate (NaNO3) and water (H2O)
    3. C.Sodium hydroxide (NaOH) and hydrogen gas (H2)
    4. D.Sodium oxide (Na2O) and hydrogen gas (H2)
    Show answer

    Answer: C Sodium hydroxide (NaOH) and hydrogen gas (H2)

  15. 15.
    Stainless steel is an alloy made up of
    1. A.Iron and zinc
    2. B.Copper and tin
    3. C.Iron and chromium
    4. D.Iron and carbon
    Show answer

    Answer: D Iron and carbon

  16. 16.
    The contact process is used for the industrial production of
    1. A.sulfuric acid (H2SO4)
    2. B.Hydrochloric acid (HCl)
    3. C.Sodium hydroxide (NaOH)
    4. D.Calcium oxide (CaO)
    Show answer

    Answer: A sulfuric acid (H2SO4)

  17. 17.
    The heat of reaction can be determined experimentally using a device called a
    1. A.Calorimeter
    2. B.Barometer
    3. C.Spectrometer
    4. D.Thermometer
    Show answer

    Answer: A Calorimeter

  18. 18.
    The lanthanides and actinides are located in which block of the periodic table?
    1. A.P-block
    2. B.S-block
    3. C.F-block
    4. D.D-block
    Show answer

    Answer: C F-block

  19. 19.
    The process of rusting is an example of the formation of
    1. A.Basic oxide
    2. B.Acidic oxide
    3. C.Reducing oxide
    4. D.Amphoteric oxide
    Show answer

    Answer: A Basic oxide

  20. 20.
    What happens to the position of equilibrium, if a reversible exothermic reaction is subjected to a decrease in temperature?
    1. A.The position of equilibrium shifts to the left
    2. B.The position of equilibrium shifts to the right
    3. C.The position of equilibrium remains unchanged
    4. D.The reaction stops
    Show answer

    Answer: B The position of equilibrium shifts to the right

  21. 21.
    What happens to the value of the equilibrium constant (Kc) for a reaction if the reaction is reversed?
    1. A.It becomes zero
    2. B.It becomes negative
    3. C.It remains the same
    4. D.It becomes the reciprocal of the original value
    Show answer

    Answer: D It becomes the reciprocal of the original value

  22. 22.
    What happens when alkanoic acids react with alcohols in the presence of an acid catalyst?
    1. A.Saponification
    2. B.Esterification
    3. C.Polymerization
    4. D.Hydrolysis
    Show answer

    Answer: B Esterification

  23. 23.
    What is eutrophication?
    1. A.The release of harmful chemicals into water bodies
    2. B.The excessive growth of algae due to nutrient enrichment
    3. C.The presence of heavy metals in water
    4. D.The formation of oil slicks on water surfaces
    Show answer

    Answer: C The presence of heavy metals in water

  24. 24.
    What is Faraday's constant?
    1. A.6.022 x 10 \(^{23}\) mol \(^{-1}\)
    2. B.3.00 x 10 \(^8\) m/s
    3. C.9.81 m/s \(^2\)
    4. D.96,485 C/mol
    Show answer

    Answer: D 96,485 C/mol

  25. 25.
    What is the atomic number of aluminium?
    1. A.13
    2. B.26
    3. C.14
    4. D.12
    Show answer

    Answer: A 13

  26. 26.
    What is the chemical formula of rust, which is formed on the surface of iron in the presence of oxygen and moisture?
    1. A.Fe \(_3\) O \(_4\)
    2. B.FeO
    3. C.Fe(OH)3
    4. D.Fe \(_2\) O \(_3\)
    Show answer

    Answer: A Fe \(_3\) O \(_4\)

  27. 27.
    What is the chemical structure of soap and detergent molecules?
    1. A.Hydrophilic head and hydrophobic tail
    2. B.Hydrophilic head and hydrophilic tail
    3. C.Hydrophobic head and hydrophobic tail
    4. D.Hydrophilic tail and hydrophobic head
    Show answer

    Answer: A Hydrophilic head and hydrophobic tail

  28. 28.
    What is the common name for ethanoic acid?
    1. A.Acetic acid
    2. B.Butyric acid
    3. C.Propionic acid
    4. D.Formic acid
    Show answer

    Answer: A Acetic acid

  29. 29.
    What is the empirical formula of a compound containing 40.00% carbon, 6.67% hydrogen, and 53.33% oxygen by mass?
    1. A.C \(_4\) H \(_8\) O \(_4\)
    2. B.CH \(_2\) O
    3. C.C \(_2\) H \(_4\) O \(_2\)
    4. D.C \(_3\) H \(_6\) O \(_3\)
    Show answer

    Answer: D C \(_3\) H \(_6\) O \(_3\)

  30. 30.
    What is the IUPAC name for the compound CCl \(_4\) ?
    1. A.Tetrahydrochloride
    2. B.Tetrachloromethane
    3. C.Carbon tetrachloride
    4. D.Chloroform
    Show answer

    Answer: B Tetrachloromethane

  31. 31.
    What is the main environmental concern associated with sulfur dioxide emissions?
    1. A.Formation of acid rain
    2. B.Global warming potential
    3. C.Depletion of the stratospheric ozone
    4. D.Depletion of the ozone layer
    Show answer

    Answer: A Formation of acid rain

  32. 32.
    What is the main source of carbon monoxide (CO) in urban areas?
    1. A.Volcanic eruptions
    2. B.Vehicle emissions
    3. C.Forest fires
    4. D.Industrial processes
    Show answer

    Answer: B Vehicle emissions

  33. 33.
    What is the mass (in grams) of 500 mL of ethanol? (density of ethanol = 0.789 g/mL)
    1. A.394.5 mL
    2. B.500 mL
    3. C.394.5 g
    4. D.500 g
    Show answer

    Answer: C 394.5 g

  34. 34.
    What is the mass percentage of carbon (C) in methane (CH4)? (The molar mass of carbon is approximately 12 g/mol.)
    1. A.25%
    2. B.12%
    3. C.75%
    4. D.50%
    Show answer

    Answer: C 75%

  35. 35.
    What is the maximum number of electrons that can occupy the second energy level (n=2)?
    1. A.2 electrons
    2. B.18 electrons
    3. C.8 electrons
    4. D.32 electrons
    Show answer

    Answer: C 8 electrons

  36. 36.
    What is the molar mass of water (H2O)?
    1. A.18 g/mol
    2. B.22 g/mol
    3. C.16 g/mol
    4. D.12 g/mol
    Show answer

    Answer: A 18 g/mol

  37. 37.
    What is the molecular geometry of a molecule with three bonding pairs and no lone pairs around the central atom?
    1. A.Tetrahedral
    2. B.Trigonal planar
    3. C.Linear
    4. D.Octahedral
    Show answer

    Answer: B Trigonal planar

  38. 38.
    What is the name of the process by which ammonia is produced on an industrial scale?
    1. A.Nitrogenation
    2. B.Ammoniation
    3. C.Nitrification
    4. D.Haber process
    Show answer

    Answer: D Haber process

  39. 39.
    What is the principal ore of iron, from which iron is extracted?
    1. A.Calcite
    2. B.Bauxite
    3. C.Magnetite
    4. D.Hematite
    Show answer

    Answer: D Hematite

  40. 40.
    What is the product of the electrolysis of aqueous sodium chloride (NaCl) using inert electrodes?
    1. A.Hydrogen gas at the cathode and chlorine gas at the anode
    2. B.Hydrogen gas at the cathode and oxygen gas at the anode
    3. C.Sodium metal at the cathode and chlorine gas at the anode
    4. D.Sodium metal at the cathode and oxygen gas at the anode
    Show answer

    Answer: B Hydrogen gas at the cathode and oxygen gas at the anode

  41. 41.
    What is the solubility product constant (Ksp) used for?
    1. A.To measure the total mass of a solute that can dissolve in a solvent
    2. B.To determine the concentration of a solute in a saturated solution
    3. C.To calculate the solubility of a solute in a given solvent
    4. D.To compare the solubilities of different solutes in the same solvent
    Show answer

    Answer: B To determine the concentration of a solute in a saturated solution

  42. 42.
    What is the state of matter in which particles are widely spaced and move freely with high kinetic energy?
    1. A.Liquid
    2. B.Solid
    3. C.Plasma
    4. D.Gas
    Show answer

    Answer: D Gas

  43. 43.
    What is the sum of the oxidation numbers in a neutral compound?
    1. A.+2
    2. B.-1
    3. C.0
    4. D.+1
    Show answer

    Answer: D +1

  44. 44.
    What is the symbol used to represent an alpha particle?
    1. A.α
    2. B.γ
    3. C.δ
    4. D.β
    Show answer

    Answer: A α

  45. 45.
    What is the trend for ionization energy across a period in the periodic table?
    1. A.Increases from left to right
    2. B.Remains constant
    3. C.Varies randomly
    4. D.Decreases from left to right
    Show answer

    Answer: A Increases from left to right

  46. 46.
    What is the valency of an element with the electronic configuration 2, 8, 7?
    1. A.7
    2. B.1
    3. C.2
    4. D.3
    Show answer

    Answer: B 1

  47. 47.
    What type of reaction is involved in the formation of alkanols from alkenes?
    1. A.Elimination reaction
    2. B.Redox reaction
    3. C.Substitution reaction
    4. D.Addition reaction
    Show answer

    Answer: A Elimination reaction

  48. 48.
    What unit of temperature should be used when applying the ideal gas law?
    1. A.Fahrenheit (°F)
    2. B.Kelvin (K)
    3. C.Rankine (°R)
    4. D.Celsius (°C)
    Show answer

    Answer: A Fahrenheit (°F)

  49. 49.
    When a substance is oxidized, it
    1. A.Loses electrons
    2. B.Gains oxygen atoms
    3. C.Gains electrons
    4. D.Loses protons (H+ ions)
    Show answer

    Answer: A Loses electrons

  50. 50.
    When an acidic solution is diluted, what happens to its pH?
    1. A.It depends on the specific acid
    2. B.It decreases
    3. C.It remains the same
    4. D.It increases
    Show answer

    Answer: D It increases

  51. 51.
    When anhydrous cobalt chloride paper is exposed to water, what color change is observed?
    1. A.From pink to blue
    2. B.From white to blue
    3. C.From blue to white
    4. D.From blue to pink
    Show answer

    Answer: D From blue to pink

  52. 52.
    Which element is placed at the top of the electrochemical series?
    1. A.Copper
    2. B.Hydrogen
    3. C.Sodium
    4. D.Oxygen
    Show answer

    Answer: B Hydrogen

  53. 53.
    Which functional group is present in alkanals?
    1. A.Carbonyl group (C=O)
    2. B.Hydroxyl group (-OH)
    3. C.Alkyl group (-R)
    4. D.Carboxyl group (-COOH)
    Show answer

    Answer: A Carbonyl group (C=O)

  54. 54.
    Which group does calcium belong to in the periodic table?
    1. A.Alkaline earth metals
    2. B.Halogens
    3. C.Alkali metals
    4. D.Noble gases
    Show answer

    Answer: B Halogens

  55. 55.
    Which halogen is a gas at room temperature and is pale yellow in color?
    1. A.Chlorine (Cl)
    2. B.Fluorine (F)
    3. C.Iodine (I)
    4. D.Bromine (Br)
    Show answer

    Answer: B Fluorine (F)

  56. 56.
    Which noble gas is radioactive and is produced as a decay product of uranium and thorium?
    1. A.Argon
    2. B.Krypton
    3. C.Radon
    4. D.Neon
    Show answer

    Answer: C Radon

  57. 57.
    Which of the following alkanes has a straight-chain structure?
    1. A.Cyclopentane (C5H10)
    2. B.Isobutane (C4H10)
    3. C.2 - methyl propane (C4H10)
    4. D.Pentane (C5H12)
    Show answer

    Answer: D Pentane (C5H12)

  58. 58.
    Which of the following compounds is an example of an electrovalent bond?
    1. A.NaCl (sodium chloride)
    2. B.CO2 (carbon dioxide)
    3. C.H2O (water)
    4. D.CH4 (methane)
    Show answer

    Answer: A NaCl (sodium chloride)

  59. 59.
    Which of the following factors does NOT affect the rate of a chemical reaction?
    1. A.Concentration of reactants
    2. B.Presence of a catalyst
    3. C.Molecular weight of products
    4. D.Temperature
    Show answer

    Answer: D Temperature

  60. 60.
    Which of the following is a characteristic property of acids?
    1. A.Turn litmus paper blue
    2. B.Bitter taste
    3. C.pH value above 7
    4. D.React with metals to produce hydrogen gas
    Show answer

    Answer: D React with metals to produce hydrogen gas

  61. 61.
    Which of the following is a common laboratory indicator for bases?
    1. A.Methyl orange
    2. B.Phenolphthalein
    3. C.Bromothymol blue
    4. D.Litmus
    Show answer

    Answer: B Phenolphthalein

  62. 62.
    Which of the following is a common property of non-metals?
    1. A.Exist as solids at room temperature
    2. B.Tend to gain electrons in chemical reactions
    3. C.High thermal conductivity
    4. D.Readily form cations in chemical reactions
    Show answer

    Answer: B Tend to gain electrons in chemical reactions

  63. 63.
    Which of the following is a primary constituent of crude oil?
    1. A.Pentane
    2. B.Ethanol
    3. C.Heptane
    4. D.Methane
    Show answer

    Answer: D Methane

  64. 64.
    Which of the following is a unique property of water compared to other liquids?
    1. A.It is a poor solvent
    2. B.It does not evaporate
    3. C.It expands when freezing
    4. D.It has a low heat capacity
    Show answer

    Answer: B It does not evaporate

  65. 65.
    Which of the following is an example of a primary cell?
    1. A.Alkaline battery
    2. B.Nickel-cadmium battery
    3. C.Lead-acid battery
    4. D.Lithium-ion battery
    Show answer

    Answer: A Alkaline battery

  66. 66.
    Which of the following is an example of an endothermic reaction?
    1. A.Combustion of propane (C \(_3\) H \(_8\) ) to produce carbon dioxide (CO \(_2\) ) and water (H \(_2\) O)
    2. B.Burning of methane (CH \(_4\) ) in the presence of oxygen
    3. C.Formation of table salt (NaCl) from sodium (Na) and chlorine (Cl \(_2\) )
    4. D.Decomposition of hydrogen peroxide (H \(_2\) O \(_2\) ) into water (H \(_2\) O) and oxygen (O \(_2\) )
    Show answer

    Answer: C Formation of table salt (NaCl) from sodium (Na) and chlorine (Cl \(_2\) )

  67. 67.
    Which of the following metals is commonly alloyed with copper to make brass?
    1. A.Iron
    2. B.Nickel
    3. C.Aluminum
    4. D.Zinc
    Show answer

    Answer: C Aluminum

  68. 68.
    Which of the following methods can be used to remove temporary hardness from water?
    1. A.Boiling
    2. B.Filtration
    3. C.sedimentation
    4. D.Chlorination
    Show answer

    Answer: A Boiling

  69. 69.
    Which of the following methods is commonly used to remove suspended impurities from water?
    1. A.Fluoridation
    2. B.Chlorination
    3. C.Filtration
    4. D.Distillation
    Show answer

    Answer: C Filtration

  70. 70.
    Which of the following mixtures is an example of a colloid?
    1. A.Milk
    2. B.Orange juice
    3. C.Saltwater
    4. D.Sugar dissolved in water
    Show answer

    Answer: A Milk

  71. 71.
    Which of the following reactions would be expected to have the highest entropy change?
    1. A.Liquid → Gas
    2. B.Solid → Liquid
    3. C.Gas → Liquid
    4. D.Gas → Solid
    Show answer

    Answer: A Liquid → Gas

  72. 72.
    Which of the following statements is true for strong electrolytes?
    1. A.They do not conduct electricity in the molten state
    2. B.They completely dissociate into ions in solution
    3. C.They are non-polar substances
    4. D.They partially dissociate into ions in solution
    Show answer

    Answer: B They completely dissociate into ions in solution

  73. 73.
    Which of the following statements is true regarding the melting and boiling points of pure substances?
    1. A.The boiling point is always higher than the melting point
    2. B.The melting point is always higher than the boiling point
    3. C.The melting and boiling points are always the same for all substances
    4. D.The melting and boiling points can vary depending on the substance
    Show answer

    Answer: C The melting and boiling points are always the same for all substances

  74. 74.
    Which of the following substances is NOT hygroscopic?
    1. A.Salt
    2. B.Sugar
    3. C.Silica gel
    4. D.Aluminum
    Show answer

    Answer: D Aluminum

  75. 75.
    Which organic compound is responsible for the characteristic aroma of fruits?
    1. A.Alkane
    2. B.Alkyne
    3. C.Ester
    4. D.Amine
    Show answer

    Answer: C Ester

  76. 76.
    Which separation technique is used to separate different pigments in a mixture based on their affinity for a stationary phase and a mobile phase?
    1. A.Chromatography
    2. B.Filtration
    3. C.Decantation
    4. D.Distillation
    Show answer

    Answer: C Decantation

  77. 77.
    Which trace gas in the atmosphere plays a significant role in the greenhouse effect?
    1. A.Oxygen
    2. B.Argon
    3. C.Carbon dioxide
    4. D.Nitrogen
    Show answer

    Answer: C Carbon dioxide

  78. 78.
    Which transition metal is known for its multiple colorful oxidation states and compounds used in pigments and paints?
    1. A.Silver (Ag)
    2. B.Copper (Cu)
    3. C.Gold (Au)
    4. D.Zinc (Zn)
    Show answer

    Answer: D Zinc (Zn)

  79. 79.
    Which type of chemical combination involves the transfer of electrons from one atom to another, resulting in the formation of oppositely charged ions?
    1. A.Ionic bonding
    2. B.Hydrogen bonding
    3. C.Covalent bonding
    4. D.Metallic bonding
    Show answer

    Answer: A Ionic bonding

  80. 80.
    Which type of salt is found in antacid medications and is used to relieve heartburn and indigestion?
    1. A.Aluminum chloride
    2. B.Magnesium chloride
    3. C.Sodium chloride
    4. D.Calcium chloride
    Show answer

    Answer: B Magnesium chloride

  81. 81.
    Who proposed the planetary model of the atom with electrons orbiting the nucleus?
    1. A.Erwin Schrödinger
    2. B.Ernest Rutherford
    3. C.Niels Bohr
    4. D.J.J. Thomson
    Show answer

    Answer: B Ernest Rutherford

  82. 82.
    Why is water often referred to as the "universal solvent"?
    1. A.Water is the most abundant substance on Earth
    2. B.Water is essential for all living organisms
    3. C.Water is involved in many chemical reactions
    4. D.Water can dissolve a wide variety of substances due to its polar nature
    Show answer

    Answer: D Water can dissolve a wide variety of substances due to its polar nature

Printing is turned off here to protect the question bank. Get the SmarTest app to study offline.

More free Chemistry papers

JAMB Chemistry 1978–2020 is in the app

The latest five years of each paper are free here. The SmarTest app has every year we hold, a worked explanation for each answer, and timed mock exams. It works offline.

Get the app

Android, Windows, Mac and Linux