Preparing for your Post-UTME Chemistry exam?
This collection of carefully selected Post-UTME past questions and answers is designed to help you practice and boost your confidence for success. Whether you’re applying to UNILAG, OAU, UNN, UI, or other top Nigerian universities, this resource will guide you through the types of questions to expect.
Below, you’ll find both objective and theory post UTME Chemistry past questions with answers to sharpen your preparation.
POST-UTME CHEMISTRY PAST QUESTIONS (1–100)
(Multiple Choice with Answers)
1. Which of the following is a chemical change?
A. Melting of ice B. Burning of paper C. Dissolving sugar in water D. Breaking of glass
Answer: B
2. Which of these is a noble gas?
A. Nitrogen B. Oxygen C. Argon D. Hydrogen
Answer: C
3. What is the valency of calcium?
A. 1 B. 2 C. 3 D. 4
Answer: B
4. The number of protons in the nucleus of an atom is called its:
A. mass number B. atomic number C. isotope D. neutron number
Answer: B
5. Which of the following is a mixture?
A. Distilled water B. Oxygen C. Air D. Pure gold
Answer: C
6. Which subatomic particle carries a negative charge?
A. Proton B. Neutron C. Electron D. Positron
Answer: C
7. The formula of sodium chloride is:
A. NaCl B. NaCO₃ C. Na₂O D. NaOH
Answer: A
8. The atomic number of an element is 9. Its electronic configuration is:
A. 2,7 B. 2,8 C. 2,6 D. 2,2
Answer: A
9. A catalyst is a substance that:
A. slows down a reaction
B. speeds up a reaction without being used up
C. starts a reaction
D. increases the mass of reactants
Answer: B
10. Which of the following is a physical property of matter?
A. Rusting B. Colour C. Burning D. Decomposition
Answer: B
11. Which of these is an exothermic process?
A. Melting of ice B. Evaporation C. Condensation D. Sublimation
Answer: C
12. The mass number of an atom is the total number of:
A. protons B. neutrons C. electrons D. protons and neutrons
Answer: D
13. The pH of a neutral solution is:
A. 1 B. 7 C. 14 D. 0
Answer: B
14. Which of the following is a base?
A. NaOH B. HCl C. H₂SO₄ D. CH₃COOH
Answer: A
15. Which of the following is an organic compound?
A. NaCl B. CH₄ C. CaO D. KNO₃
Answer: B
16. What is the chemical symbol for potassium?
A. Po B. K C. P D. Pt
Answer: B
17. The process by which a liquid changes to gas is called:
A. Sublimation B. Freezing C. Condensation D. Evaporation
Answer: D
18. What type of bond is formed when electrons are shared?
A. Ionic B. Metallic C. Covalent D. Electrovalent
Answer: C
19. Water is an example of a:
A. mixture B. compound C. element D. ion
Answer: B
20. An element with atomic number 2 is:
A. Hydrogen B. Lithium C. Helium D. Oxygen
Answer: C
21. Which of the following is a metalloid?
A. Copper B. Zinc C. Silicon D. Sulphur
Answer: C
22. Which is a method of separating a mixture of salt and water?
A. Filtration B. Decantation C. Distillation D. Crystallization
Answer: C
23. The modern periodic table is arranged in order of:
A. atomic mass B. atomic number C. valency D. group
Answer: B
24. A solution that turns red litmus blue is:
A. acidic B. basic C. neutral D. salty
Answer: B
25. What is the oxidation state of nitrogen in NH₃?
A. -3 B. 0 C. +1 D. +3
Answer: A
Post-Utme Chemistry Past Questions
26. What is the IUPAC name for NaHCO₃?
A. Sodium carbonate
B. Sodium bicarbonate
C. Sodium hydrogen carbonate
D. Sodium hydroxide
Answer: C
27. The reaction between an acid and a base is called:
A. combustion B. displacement C. neutralization D. oxidation
Answer: C
28. The instrument used to measure temperature is called:
A. barometer B. thermometer C. hygrometer D. voltmeter
Answer: B
29. What is the molar mass of water (H₂O)?
A. 16 g/mol B. 17 g/mol C. 18 g/mol D. 20 g/mol
Answer: C
30. An atom of chlorine has 17 protons and 18 neutrons. Its mass number is:
A. 17 B. 18 C. 34 D. 35
Answer: D
31. Which of the following metals can displace hydrogen from acids?
A. Gold B. Copper C. Zinc D. Silver
Answer: C
32. What type of reaction is: 2Mg + O₂ → 2MgO?
A. Decomposition B. Displacement C. Combination D. Double displacement
Answer: C
33. Which of these gases is responsible for acid rain?
A. Oxygen B. Nitrogen C. Sulphur dioxide D. Hydrogen
Answer: C
34. What is the gas evolved when metals react with acids?
A. Oxygen B. Hydrogen C. Nitrogen D. Carbon dioxide
Answer: B
35. The metal extracted from bauxite is:
A. Iron B. Copper C. Aluminium D. Tin
Answer: C
36. The atomic number of oxygen is:
A. 6 B. 7 C. 8 D. 9
Answer: C
37. The electrons in the outermost shell of an atom are called:
A. core electrons B. valence electrons C. bonding electrons D. orbital electrons
Answer: B
38. The colour of methyl orange in acid is:
A. Yellow B. Pink C. Red D. Orange
Answer: C
39. The periodic table was first developed by:
A. Dalton B. Mendeleev C. Thomson D. Bohr
Answer: B
40. The process by which solid iodine changes directly to gas is:
A. Melting B. Sublimation C. Evaporation D. Condensation
Answer: B
41. The number of moles in 36g of water (H₂O) is:
A. 1 B. 2 C. 3 D. 4
Answer: B
42. The rate of diffusion increases with:
A. temperature B. mass C. pressure D. volume
Answer: A
43. Which gas is used in fire extinguishers?
A. Oxygen B. Carbon dioxide C. Nitrogen D. Helium
Answer: B
44. The electrolysis of water gives:
A. Hydrogen and oxygen
B. Hydrogen and nitrogen
C. Oxygen and carbon dioxide
D. Hydrogen and hydrogen
Answer: A
45. What is the chemical formula for sulphuric acid?
A. H₂SO₄ B. HNO₃ C. HCl D. H₂CO₃
Answer: A
46. What is the percentage composition of oxygen in H₂O?
A. 33% B. 50% C. 66% D. 89%
Answer: D
47. Which of the following is a reducing agent?
A. Oxygen B. Hydrogen C. Chlorine D. Nitrogen
Answer: B
48. Which gas is collected over water because it is insoluble?
A. CO₂ B. NH₃ C. H₂ D. Cl₂
Answer: C
49. The molar volume of a gas at STP is:
A. 11.2 dm³ B. 22.4 dm³ C. 24.0 dm³ D. 30.0 dm³
Answer: B
50. Which separation method is used to obtain pure sugar from solution?
A. Evaporation B. Distillation C. Filtration D. Crystallization
Answer: D
POST-UTME CHEMISTRY PAST QUESTIONS AND ANSWERS (51–100)
(Multiple Choice with Answers)
51. A hydrocarbon that contains only single bonds is called a:
A. alkene B. alkyne C. alkane D. aromatic compound
Answer: C
52. Which of the following is a saturated hydrocarbon?
A. C₂H₂ B. C₂H₄ C. C₂H₆ D. C₆H₆
Answer: C
53. Which substance turns limewater milky?
A. Oxygen B. Hydrogen C. Nitrogen D. Carbon dioxide
Answer: D
54. The process of converting starch to sugar is called:
A. fermentation B. oxidation C. hydrolysis D. esterification
Answer: C
55. An example of a strong acid is:
A. CH₃COOH B. H₂SO₄ C. H₂CO₃ D. HCN
Answer: B
56. The product of complete combustion of hydrocarbons is:
A. CO and H₂O B. CO₂ and H₂O C. C and H₂O D. CO₂ and CO
Answer: B
57. Which of the following is a polymer?
A. Glucose B. Ethene C. Starch D. Methane
Answer: C
58. Which of the following is an allotrope of carbon?
A. Methane B. Graphite C. Ethane D. Ethyne
Answer: B
59. Which of the following increases the rate of a chemical reaction?
A. Temperature B. Surface area C. Catalyst D. All of the above
Answer: D
60. Which of these is NOT a property of metals?
A. Ductility B. Malleability C. Poor conductivity D. High melting point
Answer: C
61. Which of the following gases is least soluble in water?
A. CO₂ B. NH₃ C. HCl D. O₂
Answer: D
62. The electrolysis of NaCl solution produces:
A. Sodium and chlorine
B. Hydrogen and chlorine
C. Hydrogen and oxygen
D. Sodium and oxygen
Answer: B
63. The element with atomic number 6 is:
A. Nitrogen B. Carbon C. Oxygen D. Hydrogen
Answer: B
64. The number of neutrons in an atom of mass number 23 and atomic number 11 is:
A. 11 B. 12 C. 23 D. 34
Answer: B
65. Which process separates immiscible liquids?
A. Filtration B. Decantation C. Chromatography D. Separating funnel
Answer: D
66. Which element has the electronic configuration 2,8,8,1?
A. Potassium B. Sodium C. Magnesium D. Calcium
Answer: A
67. Which of the following is the major component of natural gas?
A. Butane B. Methane C. Ethane D. Propane
Answer: B
68. The brown ring test is used to detect:
A. Chloride B. Sulphate C. Nitrate D. Carbonate
Answer: C
69. Which gas is responsible for the depletion of the ozone layer?
A. CO₂ B. SO₂ C. CH₄ D. CFCs
Answer: D
70. What is the oxidation number of carbon in CO₂?
A. 0 B. +2 C. +4 D. -4
Answer: C
71. What is the main source of common salt?
A. Sea water B. Rocks C. Lakes D. Volcanic eruptions
Answer: A
72. Temporary hardness in water is caused by:
A. MgSO₄ B. Ca(HCO₃)₂ C. CaSO₄ D. NaCl
Answer: B
73. Which of the following substances is used for water purification?
A. NaCl B. Al₂(SO₄)₃ C. NaOH D. CaCO₃
Answer: B
74. The major constituent of air is:
A. Oxygen B. Nitrogen C. Carbon dioxide D. Hydrogen
Answer: B
Post-Utme Chemistry Past Questions
75. What is the colour of copper(II) sulfate crystals?
A. White B. Blue C. Green D. Yellow
Answer: B
76. Which of the following undergoes sublimation?
A. Naphthalene B. Salt C. Sugar D. Ice
Answer: A
77. An element in Group I of the periodic table is likely to:
A. Gain electrons B. Lose one electron C. Lose two electrons D. Form covalent bonds
Answer: B
78. A solute is:
A. the liquid in a solution
B. the solid that dissolves
C. the product of filtration
D. the gas in air
Answer: B
79. What is the name of CH₃COOH?
A. Ethanol B. Acetic acid C. Methanoic acid D. Propanoic acid
Answer: B
80. Which of the following is a greenhouse gas?
A. Nitrogen B. Oxygen C. Carbon dioxide D. Neon
Answer: C
81. Which compound turns blue litmus paper red?
A. NaOH B. KOH C. HCl D. NH₄OH
Answer: C
82. Which acid is found in soft drinks?
A. Hydrochloric acid B. Sulphuric acid C. Carbonic acid D. Nitric acid
Answer: C
83. A metal reacts with an acid to produce a salt and:
A. Water B. Hydrogen C. Oxygen D. Ammonia
Answer: B
84. Which of the following is used in the Haber process?
A. Iron catalyst B. Nickel catalyst C. Platinum catalyst D. Copper catalyst
Answer: A
85. The chemical formula for glucose is:
A. C₆H₁₂O₆ B. C₆H₆ C. C₂H₅OH D. CH₄
Answer: A
86. What is the SI unit of pressure?
A. Joule B. Newton C. Pascal D. Watt
Answer: C
87. A substance that has a constant boiling point and composition is a:
A. compound B. mixture C. element D. pure substance
Answer: D
88. The test for hydrogen gas is that it:
A. turns limewater milky
B. puts out a flame
C. burns with a pop sound
D. turns red litmus blue
Answer: C
89. Which of the following is not an acid-base indicator?
A. Methyl orange B. Phenolphthalein C. Litmus D. Sodium chloride
Answer: D
90. A redox reaction involves:
A. only oxidation
B. only reduction
C. both oxidation and reduction
D. neutralization
Answer: C
91. The gas produced from the reaction of acid with carbonate is:
A. Oxygen B. Hydrogen C. Carbon dioxide D. Nitrogen
Answer: C
92. Which of the following is used as a drying agent?
A. Water B. NaCl C. CaCl₂ D. HCl
Answer: C
93. What is the product of the reaction between ethanol and ethanoic acid?
A. Ethyl ethanoate B. Ethene C. Glucose D. Methanoic acid
Answer: A
94. Which of the following is an inert gas?
A. Oxygen B. Neon C. Nitrogen D. Hydrogen
Answer: B
95. In chromatography, the most soluble dye travels:
A. slowly B. least distance C. furthest distance D. nowhere
Answer: C
96. In electrolysis, the anode is:
A. positive B. negative C. neutral D. none of the above
Answer: A
97. Which of the following is used to bleach paper?
A. HCl B. Cl₂ C. CO₂ D. O₂
Answer: B
98. The main component of vinegar is:
A. Methanol B. Acetic acid C. Citric acid D. Ethanol
Answer: B
99. Which of the following elements is most reactive?
A. Iron B. Copper C. Potassium D. Zinc
Answer: C
100. What is the mass of 2 moles of oxygen molecules (O₂)?
A. 16g B. 32g C. 64g D. 48g
Answer: C
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Conclusion for Chemistry POST-UTME Questions
Mastering Chemistry for your university entrance exam starts with consistent exposure to real, tested questions. These 100 Post UTME Chemistry past questions and answers give you a full-spectrum revision of key concepts, reactions, periodic trends, bonding, and practical applications. Practice regularly, understand each concept, and you’ll be fully prepared for success.