JAMB Chemistry questions

443 questions with answers and explanations. Tap an option to check yourself.

All topics Acids, bases and salts · 32 Air · 21 Atomic structure and bonding · 33 Chemical combination · 31 Chemical equilibrium · 21 Chemistry and industry · 18 Electrolysis · 22 Energy changes · 22 Environmental pollution · 17 Kinetic theory of matter and gas laws · 27 Metals and their compounds · 24 Non-metals and their compounds · 23 Organic compounds · 43 Oxidation and reduction · 22 Rates of chemical reaction · 22 Separation of mixtures and purification · 24 Solubility · 20 Water · 21

Question 101· Chemical combination· JAMB
What volume of 0.1 mol/dm³ hydrochloric acid is needed to make 250 cm³ of 0.02 mol/dm³ acid?
Explanation and discussion
Question 102· Chemical combination· JAMB
4 g of sodium hydroxide is dissolved in water to make 500 cm³ of solution. Find its concentration. (Na = 23, O = 16, H = 1)
Explanation and discussion
Question 103· Chemical combination· JAMB
The law of multiple proportions is illustrated by
Explanation and discussion
Question 104· Chemical combination· JAMB
The empirical formula of a compound containing 40% carbon, 6.7% hydrogen and 53.3% oxygen by mass is: (C = 12, H = 1, O = 16)
Explanation and discussion
Question 105· Chemical combination· JAMB
Find the percentage by mass of water of crystallisation in CuSO₄·5H₂O. (Cu = 64, S = 32, O = 16, H = 1)
Explanation and discussion
Question 106· Chemical combination· JAMB
In the reaction 2H₂(g) + O₂(g) → 2H₂O(l), what volume of oxygen reacts completely with 20 cm³ of hydrogen at the same temperature and pressure?
Explanation and discussion
Question 107· Chemical combination· JAMB
Find the mass of 3.01 × 10²³ atoms of sodium. (Na = 23; Avogadro's constant = 6.02 × 10²³ mol⁻¹)
Explanation and discussion
Question 108· Chemical combination· JAMB
0.5 g of a gas occupies 280 cm³ at s.t.p. Find its molar mass. [molar volume = 22.4 dm³]
Explanation and discussion
Question 109· Chemical combination· JAMB
How many moles are in 11 g of carbon(IV) oxide? (C = 12, O = 16)
Explanation and discussion
Question 110· Chemical combination· JAMB
How many molecules are in 0.5 mol of water? (Avogadro's constant = 6.02 × 10²³ mol⁻¹)
Explanation and discussion
Question 111· Chemical combination· JAMB
A compound contains 2.4 g of carbon and 0.6 g of hydrogen. Find its empirical formula. (C = 12, H = 1)
Explanation and discussion
Question 112· Chemical combination· JAMB
A compound contains 80% carbon and 20% hydrogen by mass, and its molar mass is 30 g/mol. Find its molecular formula. [C = 12, H = 1]
Explanation and discussion
Question 113· Chemical combination· JAMB
A compound has the empirical formula CH₂O and a relative molecular mass of 180. Find its molecular formula. (C = 12, H = 1, O = 16)
Explanation and discussion
Question 114· Chemical combination· JAMB
The statement that in a closed system the total mass of reactants equals the total mass of products is the law of
Explanation and discussion
Question 115· Chemical combination· JAMB
Find the molar mass of sodium trioxocarbonate(IV), Na₂CO₃. (Na = 23, C = 12, O = 16)
Explanation and discussion
Question 116· Chemical combination· JAMB
Find the mass of 0.25 mol of calcium trioxocarbonate(IV), CaCO₃. (Ca = 40, C = 12, O = 16)
Explanation and discussion
Question 117· Chemical combination· JAMB
In 2H₂ + O₂ → 2H₂O, what volume of oxygen is needed to burn 40 cm³ of hydrogen at the same temperature and pressure?
Explanation and discussion
Question 118· Chemical equilibrium· JAMB
Adding a catalyst to a reaction at equilibrium
Explanation and discussion
Question 119· Chemical equilibrium· JAMB
For H₂(g) + I₂(g) ⇌ 2HI(g), increasing the pressure
Explanation and discussion
Question 120· Chemical equilibrium· JAMB
For the equilibrium N₂ + 3H₂ ⇌ 2NH₃ (ΔH negative), the yield of ammonia is increased by:
Explanation and discussion

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JAMB Chemistry questions

What volume of 0.1 mol/dm³ hydrochloric acid is needed to make 250 cm³ of 0.02 mol/dm³ acid?

4 g of sodium hydroxide is dissolved in water to make 500 cm³ of solution. Find its concentration. (Na = 23, O = 16, H = 1)

The law of multiple proportions is illustrated by

The empirical formula of a compound containing 40% carbon, 6.7% hydrogen and 53.3% oxygen by mass is: (C = 12, H = 1, O = 16)

Find the percentage by mass of water of crystallisation in CuSO₄·5H₂O. (Cu = 64, S = 32, O = 16, H = 1)

In the reaction 2H₂(g) + O₂(g) → 2H₂O(l), what volume of oxygen reacts completely with 20 cm³ of hydrogen at the same temperature and pressure?

Find the mass of 3.01 × 10²³ atoms of sodium. (Na = 23; Avogadro's constant = 6.02 × 10²³ mol⁻¹)

0.5 g of a gas occupies 280 cm³ at s.t.p. Find its molar mass. [molar volume = 22.4 dm³]

How many moles are in 11 g of carbon(IV) oxide? (C = 12, O = 16)

How many molecules are in 0.5 mol of water? (Avogadro's constant = 6.02 × 10²³ mol⁻¹)

A compound contains 2.4 g of carbon and 0.6 g of hydrogen. Find its empirical formula. (C = 12, H = 1)

A compound contains 80% carbon and 20% hydrogen by mass, and its molar mass is 30 g/mol. Find its molecular formula. [C = 12, H = 1]

A compound has the empirical formula CH₂O and a relative molecular mass of 180. Find its molecular formula. (C = 12, H = 1, O = 16)

The statement that in a closed system the total mass of reactants equals the total mass of products is the law of

Find the molar mass of sodium trioxocarbonate(IV), Na₂CO₃. (Na = 23, C = 12, O = 16)

Find the mass of 0.25 mol of calcium trioxocarbonate(IV), CaCO₃. (Ca = 40, C = 12, O = 16)

In 2H₂ + O₂ → 2H₂O, what volume of oxygen is needed to burn 40 cm³ of hydrogen at the same temperature and pressure?

Adding a catalyst to a reaction at equilibrium

For H₂(g) + I₂(g) ⇌ 2HI(g), increasing the pressure

For the equilibrium N₂ + 3H₂ ⇌ 2NH₃ (ΔH negative), the yield of ammonia is increased by: