JAMB and WAEC Chemistry questions

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

All topics Acids, bases and salts · 58 Air · 37 Atomic structure and bonding · 59 Chemical combination · 58 Chemical equilibrium · 37 Chemistry and industry · 35 Electrolysis · 41 Energy changes · 38 Environmental pollution · 32 Kinetic theory of matter and gas laws · 45 Metals and their compounds · 47 Non-metals and their compounds · 45 Organic compounds · 72 Oxidation and reduction · 41 Rates of chemical reaction · 38 Separation of mixtures and purification · 42 Solubility · 36 Water · 39

Question 721· Separation of mixtures and purification· WAEC
Which method is best for separating a mixture of ethanol and water?
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Answer: B. fractional distillation
Explanation and discussion
Question 722· Separation of mixtures and purification· WAEC
In paper chromatography, the component that travels furthest is the one that is
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Answer: C. most soluble in the solvent and least attracted to the paper
Explanation and discussion
Question 723· Separation of mixtures and purification· JAMB
The components of liquid air are separated by fractional distillation because they have different
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Answer: D. boiling points
Explanation and discussion
Question 724· Separation of mixtures and purification· JAMB
Decantation is used to separate
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Answer: D. a liquid from a solid that has settled at the bottom
Explanation and discussion
Question 725· Separation of mixtures and purification· JAMB
In a paper chromatogram, a spot moves 3 cm while the solvent front moves 6 cm. Find the Rf value of the spot.
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Answer: B. 0.5
Explanation and discussion
Question 726· Solubility· WAEC
A solution that can dissolve no more solute at a given temperature is said to be
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Answer: C. saturated
Explanation and discussion
Question 727· Solubility· WAEC
A solution in which more solute can still dissolve at that temperature is
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Answer: A. unsaturated
Explanation and discussion
Question 728· Solubility· WAEC
Particles in a colloid differ from those in a true solution in that they
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Answer: C. scatter light (the Tyndall effect)
Explanation and discussion
Question 729· Solubility· JAMB
A suspension differs from a colloid in that
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Answer: A. its particles settle on standing
Explanation and discussion
Question 730· Solubility· JAMB
The scattering of a beam of light passing through a liquid (the Tyndall effect) shows that the liquid is
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Answer: C. a colloid
Explanation and discussion
Question 731· Solubility· JAMB
In a solution of sugar in water, the water is the
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Answer: A. solvent
Explanation and discussion
Question 732· Solubility· WAEC
The solubility of most gases in water
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Answer: D. decreases as temperature rises
Explanation and discussion
Question 733· Solubility· WAEC
Fish in a shallow pond may die on a very hot afternoon mainly because
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Answer: D. less oxygen dissolves in warm water
Explanation and discussion
Question 734· Solubility· WAEC
The solubility of KCl at 30 °C is 37 g per 100 g of water. What mass of KCl saturates 200 g of water at 30 °C?
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Answer: C. 74 g
Explanation and discussion
Question 735· Solubility· WAEC
The solubility of a salt is 30 g per 100 g of water at 25 °C. The mass that dissolves in 250 g of water is
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Answer: B. 75 g
Explanation and discussion
Question 736· Solubility· JAMB
50 g of a salt saturates 200 g of water at 30 °C. Find its solubility in grams per 100 g of water.
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Answer: A. 25 g
Explanation and discussion
Question 737· Solubility· JAMB
Find the concentration in g/dm³ of a 0.5 mol/dm³ solution of sodium hydroxide. (NaOH = 40)
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Answer: C. 20 g/dm³
Explanation and discussion
Question 738· Solubility· JAMB
The solubility of sodium chloride at 25 °C is 36 g per 100 g of water. What mass will dissolve in 50 g of water at 25 °C?
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Answer: D. 18 g
Explanation and discussion
Question 739· Solubility· WAEC
Crystals form when a hot saturated solution of potassium trioxonitrate(V) is cooled because
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Answer: A. its solubility falls as the temperature falls
Explanation and discussion
Question 740· Solubility· JAMB
A suspension differs from a true solution in that its particles
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Answer: C. are large enough to settle out
Explanation and discussion

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JAMB and WAEC Chemistry questions

Which method is best for separating a mixture of ethanol and water?

In paper chromatography, the component that travels furthest is the one that is

The components of liquid air are separated by fractional distillation because they have different

Decantation is used to separate

In a paper chromatogram, a spot moves 3 cm while the solvent front moves 6 cm. Find the Rf value of the spot.

A solution that can dissolve no more solute at a given temperature is said to be

A solution in which more solute can still dissolve at that temperature is

Particles in a colloid differ from those in a true solution in that they

A suspension differs from a colloid in that

The scattering of a beam of light passing through a liquid (the Tyndall effect) shows that the liquid is

In a solution of sugar in water, the water is the

The solubility of most gases in water

Fish in a shallow pond may die on a very hot afternoon mainly because

The solubility of KCl at 30 °C is 37 g per 100 g of water. What mass of KCl saturates 200 g of water at 30 °C?

The solubility of a salt is 30 g per 100 g of water at 25 °C. The mass that dissolves in 250 g of water is

50 g of a salt saturates 200 g of water at 30 °C. Find its solubility in grams per 100 g of water.

Find the concentration in g/dm³ of a 0.5 mol/dm³ solution of sodium hydroxide. (NaOH = 40)

The solubility of sodium chloride at 25 °C is 36 g per 100 g of water. What mass will dissolve in 50 g of water at 25 °C?

Crystals form when a hot saturated solution of potassium trioxonitrate(V) is cooled because

A suspension differs from a true solution in that its particles