WAEC Chemistry questions

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

All topics Acids, bases and salts · 26 Air · 16 Atomic structure and bonding · 26 Chemical combination · 27 Chemical equilibrium · 16 Chemistry and industry · 17 Electrolysis · 19 Energy changes · 16 Environmental pollution · 15 Kinetic theory of matter and gas laws · 18 Metals and their compounds · 23 Non-metals and their compounds · 22 Organic compounds · 29 Oxidation and reduction · 19 Rates of chemical reaction · 16 Separation of mixtures and purification · 18 Solubility · 16 Water · 18

Question 301· Rates of chemical reaction· WAEC
In the decomposition of hydrogen peroxide, manganese(IV) oxide
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Answer: A. speeds up the reaction and is unchanged at the end
Explanation and discussion
Question 302· Rates of chemical reaction· WAEC
Powdered marble reacts faster with acid than lumps because
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Answer: D. it has a larger surface area
Explanation and discussion
Question 303· Rates of chemical reaction· WAEC
The rate of a reaction that produces a gas can be followed by measuring the
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Answer: C. volume of gas collected at time intervals
Explanation and discussion
Question 304· Rates of chemical reaction· WAEC
Increasing the temperature increases the rate of a reaction mainly because
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Answer: D. more particles have enough energy to react
Explanation and discussion
Question 305· Rates of chemical reaction· WAEC
Food preservatives work mainly by
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Answer: D. slowing down the reactions that spoil food
Explanation and discussion
Question 306· Separation of mixtures and purification· WAEC
The liquid that passes through the filter paper during filtration is the
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Answer: A. filtrate
Explanation and discussion
Question 307· Separation of mixtures and purification· WAEC
A mixture of ammonium chloride and sodium chloride is separated by
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Answer: C. sublimation
Explanation and discussion
Question 308· Separation of mixtures and purification· WAEC
A mixture of chalk and water is separated by
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Answer: A. filtration
Explanation and discussion
Question 309· Separation of mixtures and purification· WAEC
In paper chromatography of a black ink, the component that travels furthest up the paper is the one that is
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Answer: C. most soluble in the solvent and least held by the paper
Explanation and discussion
Question 310· Separation of mixtures and purification· WAEC
The best method of obtaining crystals of copper(II) tetraoxosulphate(VI) from its solution is
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Answer: C. crystallisation
Explanation and discussion
Question 311· Separation of mixtures and purification· WAEC
Ogogoro is obtained by distilling fermented palm wine. The separation depends on a difference in the components'
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Answer: C. boiling points
Explanation and discussion
Question 312· Separation of mixtures and purification· WAEC
The method used to separate sand from water is
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Answer: A. filtration
Explanation and discussion
Question 313· Separation of mixtures and purification· WAEC
Which method is best for separating the coloured components of ink?
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Answer: A. Chromatography
Explanation and discussion
Question 314· Separation of mixtures and purification· WAEC
A separating funnel is used to separate
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Answer: A. two immiscible liquids such as oil and water
Explanation and discussion
Question 315· Separation of mixtures and purification· WAEC
The purity of a solid can be tested by finding its
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Answer: B. melting point
Explanation and discussion
Question 316· Separation of mixtures and purification· WAEC
Iodine can be separated from a mixture with sand by
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Answer: B. sublimation
Explanation and discussion
Question 317· Separation of mixtures and purification· WAEC
A mixture of iodine crystals and sand can best be separated by
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Answer: A. sublimation
Explanation and discussion
Question 318· Separation of mixtures and purification· WAEC
A pure substance has
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Answer: B. a sharp, fixed melting point
Explanation and discussion
Question 319· Separation of mixtures and purification· WAEC
Which method recovers solid salt from brine collected at a salt lake?
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Answer: B. evaporation
Explanation and discussion
Question 320· Separation of mixtures and purification· WAEC
Iodine can be separated from sand by
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Answer: A. sublimation
Explanation and discussion

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WAEC Chemistry questions

In the decomposition of hydrogen peroxide, manganese(IV) oxide

Powdered marble reacts faster with acid than lumps because

The rate of a reaction that produces a gas can be followed by measuring the

Increasing the temperature increases the rate of a reaction mainly because

Food preservatives work mainly by

The liquid that passes through the filter paper during filtration is the

A mixture of ammonium chloride and sodium chloride is separated by

A mixture of chalk and water is separated by

In paper chromatography of a black ink, the component that travels furthest up the paper is the one that is

The best method of obtaining crystals of copper(II) tetraoxosulphate(VI) from its solution is

Ogogoro is obtained by distilling fermented palm wine. The separation depends on a difference in the components'

The method used to separate sand from water is

Which method is best for separating the coloured components of ink?

A separating funnel is used to separate

The purity of a solid can be tested by finding its

Iodine can be separated from a mixture with sand by

A mixture of iodine crystals and sand can best be separated by

A pure substance has

Which method recovers solid salt from brine collected at a salt lake?

Iodine can be separated from sand by