2023 JAMB CHEMISTRY PAST QUESTION.
1) What happens to the position of equilibrium if a reversible reaction is subjected to a decrease in temperature?
A. The position of equilibrium shifts to the left
B. The position of equilibrium shifts to the right.
C. The position of equilibrium remains unchanged
D. The reaction stops
2) Which noble gas is radioactive and is produced as a decay product of uranium and thorium?
A. Argon
B. Krypton
C. Radon
D. Neon
3) Which of the following reactions would be expected to have the highest entropy change?
A. Liquid → Gas
B. Solid → Liquid
C. Gas → Liquid
D. Gas → Solid
4)What is the sum of the oxidation numbers in a neutral compound?
A. +2
B. -1
C. 0
D. +1
5) According to the kinetic theory of gases, the pressure exerted by a gas is due to
A. The vibrations of gas particles.
B. The weight of the gas particles
C. The attractive forces between gas particles
D. The collisions of gas particles with the container walls
6) Alkynes readily undergo addition reactions with which of the following?
A. Water (H2O)
B. Oxygen gas (O2)
C. Hydrogen gas (H2)
D. Chlorine gas (Cl2)
7) What is eutrophication?
A. The release of harmful chemicals into water bodies
B. The excessive growth of algae due to nutrient enrichment
C. The presence of heavy metals in water
D. The formation of oil slicks on water surfaces
8) What is the name of the process by which ammonia is produced on an industrial scale?
A. Nitrogenation
B. Ammoniation
C. Nitrification
D. Haber process
9) Who proposed the planetary model of the atom with electrons orbiting the nucleus?
A. Erwin Schrödinger
B. Ernest Rutherford
C. Niels Bohr
D. J.J. Thomson
10) Which of the following is an example of an endothermic reaction?
A. Combustion of propane (C3H8) to produce carbon dioxide (CO2) and water (H2O).
B. Burning of methane (CH4) in the presence of oxygen
C. Formation of table salt (NaCl) from sodium (Na) and chlorine (Cl2).
D. Decomposition of hydrogen peroxide (H2O2) into water (H2O) and oxygen (O2).
11) What happens to the value of the equilibrium constant (Kc) for a reaction if the reaction is reversed?
A. It becomes zero
B. It becomes negative
C. It remains the same
D. It becomes the reciprocal of the original value
12) What is the chemical structure of soap and detergent molecules?
A. Hydrophilic head and hydrophobic tail
B. Hydrophilic head and hydrophilic tail
C. Hydrophobic head and hydrophobic tail
D. Hydrophilic tail and hydrophobic head
13) What is the solubility product constant (Ksp) used for?
A. To measure the total mass of a solute that can dissolve in a solvent
B. To determine the concentration of a solute in a saturated solution
C. To calculate the solubility of a solute in a given solvent
D. To compare the solubilities of different solutes in the same solvent
14) Which trace gas in the atmosphere plays a significant role in the greenhouse effect?
A. Oxygen
B. Argon
C. Carbon dioxide
D. Nitrogen
15) Which of the following methods can be used to remove temporary hardness from water?
A. Boiling
B. Filtration
C. Distillation
D. Chlorination
16) What is Faraday's constant?
A. 6.022 x 1023
mol−1
B. 3.00 x 108
m/s
C. 9.81 m/s2
D. 96,485 C/mol
17) 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?
A. 6 liters
B. 1.5 liters
C. 0.75 liters
D. 3 liters
18) Stainless steel is an alloy made up of
A. Iron and zinc
B. Copper and tin
C. Iron and chromium
D. Iron and carbon
19) What is the state of matter in which particles are widely spaced and move freely with high kinetic energy?
A. Liquid
B. Solid
C. Plasma
D. Gas
20) Identify the reducing agent in the following reaction:
Zn + CuSO4
→ ZnSO4
+ Cu
A. Cu
B. Zn
C. ZnSO4
D. CuSO4
21) Balance the following redox reaction:
Fe2
O3
+ CO → Fe + CO2
A. Fe2
O3
+ CO → 2Fe + 2CO2
B. 2Fe2
O3
+ 3CO → 4Fe + 3CO2
C. Fe2
O3
+ 2CO → 2Fe + 2CO2
D. Fe2
O3
+ 3CO → 2Fe + 3CO2
22) What is the trend for ionization energy across a period in the periodic table?
A. Increases from left to right.
B. Remains constant
C. Varies randomly
D. Decreases from left to right
23) Which type of chemical combination involves the transfer of electrons from one atom to another, resulting in the formation of oppositely charged ions?
A. Ionic bonding
B. Hydrogen bonding
C. Covalent bonding
D. Metallic bonding
24) Which of the following alkanes has a straight-chain structure?
A.Cyclopentane (C5H10)
B. Isobutane (C4H10)
C. Butane (C4H10)
D. Pentane (C5H12)
25) What is the product of the electrolysis of aqueous sodium chloride (NaCl) using inert electrodes?
A. Hydrogen gas at the cathode and chlorine gas at the anode
B. Hydrogen gas at the cathode and oxygen gas at the anode
C. Sodium metal at the cathode and chlorine gas at the anode
D. Sodium metal at the cathode and oxygen gas at the anode
26) When an acidic solution is diluted, what happens to its pH?
A. It depends on the specific acid
B. It decreases
C. It remains the same
D. It increases
27) Which of the following factors does NOT affect the rate of a chemical reaction?
A. Concentration of reactants
B. Presence of a catalyst
C. Molecular weight of products
D. Temperature
28) Which organic compound is responsible for the characteristic aroma of fruits?
A. Alkane
B. Alkyne
C. Ester
D. Amine
29) What is the molar mass of water (H2O)?
A. 18 g/mol
B. 22 g/mol
C. 16 g/mol
D. 12 g/mol
30) What is the chemical formula of rust, which is formed on the surface of iron in the presence of oxygen and moisture?
A. Fe3
O4
B. FeO
C. Fe(OH)3
D. Fe2
O3
31) How many pi (π) bonds are there in an alkene with six carbon atoms?
A. 4
B. 6
C. 5
D. 3
32) What is the principal ore of iron, from which iron is extracted?
A. Calcite
B. Bauxite
C. Magnetite
D. Hematite
33) Which group does calcium belong to in the periodic table?
A. Alkaline earth metals
B. Halogens
C. Alkali metals
D. Noble gases
34) Which of the following is a primary constituent of crude oil?
A. Pentane
B. Ethanol
C. Heptane
D. Methane
35) What is the main source of carbon monoxide (CO) in urban areas?
A. Volcanic eruptions
B. Vehicle emissions
C. Forest fires
D. Industrial processes
36) What is the empirical formula of a compound containing 40.00% carbon, 6.67% hydrogen, and 53.33% oxygen by mass?
A. C4
H8
O4
B. CH2
O
C. C2
H4
O2
D. C3
H6
O3
37) Which separation technique is used to separate different pigments in a mixture based on their affinity for a stationary phase and a mobile phase?
A. Chromatography
B. Filtration
C. Decantation
D. Distillation
38) What is the common name for ethanoic acid?
A. Acetic acid
B. Butyric acid
C. Propionic acid
D. Formic acid
39) What type of reaction is involved in the formation of alkanols from alkenes?
A. Elimination reaction
B. Redox reaction
C. Substitution reaction
D. Addition reaction
40) What is the mass percentage of carbon (C) in methane (CH4)? (The molar mass of carbon is approximately 12 g/mol.)
A. 25%
B. 12%
C. 75%
D. 50%
41) Which of the following is a common property of non-metals?
A. Exist as solids at room temperature
B. Tend to gain electrons in chemical reactions
C. High thermal conductivity
D. Readily form cations in chemical reactions
42) What is the symbol used to represent an alpha particle?
A. α
B. γ
C. δ
D. β
43) When a substance is oxidized, it
A. Loses electrons
B. Gains oxygen atoms
C. Gains electrons
D. Loses protons (H+ ions)
44) A blue litmus paper turns red when dipped into a solution. What does this indicate about the solution?
A. The solution is basic
B. The solution is neutral
C. The solution is acidic
D. The litmus paper is faulty
45) Which of the following compounds is an example of an electrovalent bond?
A. NaCl (sodium chloride)
B. CO2 (carbon dioxide)
C. H2O (water)
D. CH4 (methane)
46) 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?
A. 2:1
B. 1:2
C. 1:1
D. 1:4
47) The contact process is used for the industrial production of
A. sulfuric acid (H2SO4)
B. Hydrochloric acid (HCl)
C. Sodium hydroxide (NaOH)
D. Calcium oxide (CaO)
48) Which of the following is a unique property of water compared to other liquids?
A. It is a poor solvent
B. It does not evaporate
C. It expands when freezing
D. It has a low heat capacity
49) Sodium reacts vigorously with water to produce
A. Sodium chloride (NaCl) and oxygen gas (O2)
B. Sodium nitrate (NaNO3) and water (H2O)
C. Sodium hydroxide (NaOH) and hydrogen gas (H2)
D. Sodium oxide (Na2O) and hydrogen gas (H2)
50) At room temperature and standard pressure, chlorine gas is in which state of matter?
A. Plasma
B. Solid
C. Liquid
D. Gas
CHEMISTRY ANSWERS
1-A 2-C 3-A 4-C 5-D 6-C 7-B 8-D 9-C 10-D
11-D 12-A 13-B 14-C 15-A 16-D 17-C 18-C 19-D 20-B
21-C 22-A 23-A 24-D 25-A 26-B 27-C 28-C 29-A 30-D
31-A 32-D 33-A 34-A 35-B 36-B 37-A 38-A 39-D 40-C
41-B 42-A 43-A 44-C 45-A 46-A 47-A 48-C 49-C 50-D
1) What happens to the position of equilibrium if a reversible reaction is subjected to a decrease in temperature?
A. The position of equilibrium shifts to the left
B. The position of equilibrium shifts to the right.
C. The position of equilibrium remains unchanged
D. The reaction stops
2) Which noble gas is radioactive and is produced as a decay product of uranium and thorium?
A. Argon
B. Krypton
C. Radon
D. Neon
3) Which of the following reactions would be expected to have the highest entropy change?
A. Liquid → Gas
B. Solid → Liquid
C. Gas → Liquid
D. Gas → Solid
4)What is the sum of the oxidation numbers in a neutral compound?
A. +2
B. -1
C. 0
D. +1
5) According to the kinetic theory of gases, the pressure exerted by a gas is due to
A. The vibrations of gas particles.
B. The weight of the gas particles
C. The attractive forces between gas particles
D. The collisions of gas particles with the container walls
6) Alkynes readily undergo addition reactions with which of the following?
A. Water (H2O)
B. Oxygen gas (O2)
C. Hydrogen gas (H2)
D. Chlorine gas (Cl2)
7) What is eutrophication?
A. The release of harmful chemicals into water bodies
B. The excessive growth of algae due to nutrient enrichment
C. The presence of heavy metals in water
D. The formation of oil slicks on water surfaces
8) What is the name of the process by which ammonia is produced on an industrial scale?
A. Nitrogenation
B. Ammoniation
C. Nitrification
D. Haber process
9) Who proposed the planetary model of the atom with electrons orbiting the nucleus?
A. Erwin Schrödinger
B. Ernest Rutherford
C. Niels Bohr
D. J.J. Thomson
10) Which of the following is an example of an endothermic reaction?
A. Combustion of propane (C3H8) to produce carbon dioxide (CO2) and water (H2O).
B. Burning of methane (CH4) in the presence of oxygen
C. Formation of table salt (NaCl) from sodium (Na) and chlorine (Cl2).
D. Decomposition of hydrogen peroxide (H2O2) into water (H2O) and oxygen (O2).
11) What happens to the value of the equilibrium constant (Kc) for a reaction if the reaction is reversed?
A. It becomes zero
B. It becomes negative
C. It remains the same
D. It becomes the reciprocal of the original value
12) What is the chemical structure of soap and detergent molecules?
A. Hydrophilic head and hydrophobic tail
B. Hydrophilic head and hydrophilic tail
C. Hydrophobic head and hydrophobic tail
D. Hydrophilic tail and hydrophobic head
13) What is the solubility product constant (Ksp) used for?
A. To measure the total mass of a solute that can dissolve in a solvent
B. To determine the concentration of a solute in a saturated solution
C. To calculate the solubility of a solute in a given solvent
D. To compare the solubilities of different solutes in the same solvent
14) Which trace gas in the atmosphere plays a significant role in the greenhouse effect?
A. Oxygen
B. Argon
C. Carbon dioxide
D. Nitrogen
15) Which of the following methods can be used to remove temporary hardness from water?
A. Boiling
B. Filtration
C. Distillation
D. Chlorination
16) What is Faraday's constant?
A. 6.022 x 1023
mol−1
B. 3.00 x 108
m/s
C. 9.81 m/s2
D. 96,485 C/mol
17) 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?
A. 6 liters
B. 1.5 liters
C. 0.75 liters
D. 3 liters
18) Stainless steel is an alloy made up of
A. Iron and zinc
B. Copper and tin
C. Iron and chromium
D. Iron and carbon
19) What is the state of matter in which particles are widely spaced and move freely with high kinetic energy?
A. Liquid
B. Solid
C. Plasma
D. Gas
20) Identify the reducing agent in the following reaction:
Zn + CuSO4
→ ZnSO4
+ Cu
A. Cu
B. Zn
C. ZnSO4
D. CuSO4
21) Balance the following redox reaction:
Fe2
O3
+ CO → Fe + CO2
A. Fe2
O3
+ CO → 2Fe + 2CO2
B. 2Fe2
O3
+ 3CO → 4Fe + 3CO2
C. Fe2
O3
+ 2CO → 2Fe + 2CO2
D. Fe2
O3
+ 3CO → 2Fe + 3CO2
22) What is the trend for ionization energy across a period in the periodic table?
A. Increases from left to right.
B. Remains constant
C. Varies randomly
D. Decreases from left to right
23) Which type of chemical combination involves the transfer of electrons from one atom to another, resulting in the formation of oppositely charged ions?
A. Ionic bonding
B. Hydrogen bonding
C. Covalent bonding
D. Metallic bonding
24) Which of the following alkanes has a straight-chain structure?
A.Cyclopentane (C5H10)
B. Isobutane (C4H10)
C. Butane (C4H10)
D. Pentane (C5H12)
25) What is the product of the electrolysis of aqueous sodium chloride (NaCl) using inert electrodes?
A. Hydrogen gas at the cathode and chlorine gas at the anode
B. Hydrogen gas at the cathode and oxygen gas at the anode
C. Sodium metal at the cathode and chlorine gas at the anode
D. Sodium metal at the cathode and oxygen gas at the anode
26) When an acidic solution is diluted, what happens to its pH?
A. It depends on the specific acid
B. It decreases
C. It remains the same
D. It increases
27) Which of the following factors does NOT affect the rate of a chemical reaction?
A. Concentration of reactants
B. Presence of a catalyst
C. Molecular weight of products
D. Temperature
28) Which organic compound is responsible for the characteristic aroma of fruits?
A. Alkane
B. Alkyne
C. Ester
D. Amine
29) What is the molar mass of water (H2O)?
A. 18 g/mol
B. 22 g/mol
C. 16 g/mol
D. 12 g/mol
30) What is the chemical formula of rust, which is formed on the surface of iron in the presence of oxygen and moisture?
A. Fe3
O4
B. FeO
C. Fe(OH)3
D. Fe2
O3
31) How many pi (π) bonds are there in an alkene with six carbon atoms?
A. 4
B. 6
C. 5
D. 3
32) What is the principal ore of iron, from which iron is extracted?
A. Calcite
B. Bauxite
C. Magnetite
D. Hematite
33) Which group does calcium belong to in the periodic table?
A. Alkaline earth metals
B. Halogens
C. Alkali metals
D. Noble gases
34) Which of the following is a primary constituent of crude oil?
A. Pentane
B. Ethanol
C. Heptane
D. Methane
35) What is the main source of carbon monoxide (CO) in urban areas?
A. Volcanic eruptions
B. Vehicle emissions
C. Forest fires
D. Industrial processes
36) What is the empirical formula of a compound containing 40.00% carbon, 6.67% hydrogen, and 53.33% oxygen by mass?
A. C4
H8
O4
B. CH2
O
C. C2
H4
O2
D. C3
H6
O3
37) Which separation technique is used to separate different pigments in a mixture based on their affinity for a stationary phase and a mobile phase?
A. Chromatography
B. Filtration
C. Decantation
D. Distillation
38) What is the common name for ethanoic acid?
A. Acetic acid
B. Butyric acid
C. Propionic acid
D. Formic acid
39) What type of reaction is involved in the formation of alkanols from alkenes?
A. Elimination reaction
B. Redox reaction
C. Substitution reaction
D. Addition reaction
40) What is the mass percentage of carbon (C) in methane (CH4)? (The molar mass of carbon is approximately 12 g/mol.)
A. 25%
B. 12%
C. 75%
D. 50%
41) Which of the following is a common property of non-metals?
A. Exist as solids at room temperature
B. Tend to gain electrons in chemical reactions
C. High thermal conductivity
D. Readily form cations in chemical reactions
42) What is the symbol used to represent an alpha particle?
A. α
B. γ
C. δ
D. β
43) When a substance is oxidized, it
A. Loses electrons
B. Gains oxygen atoms
C. Gains electrons
D. Loses protons (H+ ions)
44) A blue litmus paper turns red when dipped into a solution. What does this indicate about the solution?
A. The solution is basic
B. The solution is neutral
C. The solution is acidic
D. The litmus paper is faulty
45) Which of the following compounds is an example of an electrovalent bond?
A. NaCl (sodium chloride)
B. CO2 (carbon dioxide)
C. H2O (water)
D. CH4 (methane)
46) 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?
A. 2:1
B. 1:2
C. 1:1
D. 1:4
47) The contact process is used for the industrial production of
A. sulfuric acid (H2SO4)
B. Hydrochloric acid (HCl)
C. Sodium hydroxide (NaOH)
D. Calcium oxide (CaO)
48) Which of the following is a unique property of water compared to other liquids?
A. It is a poor solvent
B. It does not evaporate
C. It expands when freezing
D. It has a low heat capacity
49) Sodium reacts vigorously with water to produce
A. Sodium chloride (NaCl) and oxygen gas (O2)
B. Sodium nitrate (NaNO3) and water (H2O)
C. Sodium hydroxide (NaOH) and hydrogen gas (H2)
D. Sodium oxide (Na2O) and hydrogen gas (H2)
50) At room temperature and standard pressure, chlorine gas is in which state of matter?
A. Plasma
B. Solid
C. Liquid
D. Gas
CHEMISTRY ANSWERS
1-A 2-C 3-A 4-C 5-D 6-C 7-B 8-D 9-C 10-D
11-D 12-A 13-B 14-C 15-A 16-D 17-C 18-C 19-D 20-B
21-C 22-A 23-A 24-D 25-A 26-B 27-C 28-C 29-A 30-D
31-A 32-D 33-A 34-A 35-B 36-B 37-A 38-A 39-D 40-C
41-B 42-A 43-A 44-C 45-A 46-A 47-A 48-C 49-C 50-D