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 421· Solubility· JAMB
The solubility of KNO₃ is 60 g per 100 g of water at 40 °C and 30 g per 100 g at 20 °C. What mass of crystals forms when 160 g of saturated solution at 40 °C is cooled to 20 °C?
Show answer
Answer: C. 30 g
Explanation and discussion
Question 422· Solubility· JAMB
A saturated solution is one that:
Show answer
Answer: D. contains the maximum amount of solute at that temperature
Explanation and discussion
Question 423· Water· JAMB
Which process exchanges the Ca²⁺ and Mg²⁺ ions in hard water for Na⁺ ions?
Show answer
Answer: A. passing the water through a permutit (ion-exchange) column
Explanation and discussion
Question 424· Water· JAMB
In water treatment, suspended particles are removed mainly by
Show answer
Answer: C. sedimentation and sand filtration
Explanation and discussion
Question 425· Water· JAMB
Temporary hardness of water is removed by
Show answer
Answer: D. boiling
Explanation and discussion
Question 426· Water· JAMB
Temporary hardness of water is caused by dissolved:
Show answer
Answer: B. calcium hydrogentrioxocarbonate(IV)
Explanation and discussion
Question 427· Water· JAMB
Ion-exchange resins soften water by
Show answer
Answer: D. replacing calcium and magnesium ions with sodium ions
Explanation and discussion
Question 428· Water· JAMB
Which substance removes both temporary and permanent hardness of water?
Show answer
Answer: A. sodium trioxocarbonate(IV) (washing soda)
Explanation and discussion
Question 429· Water· JAMB
Water is regarded as a compound because
Show answer
Answer: D. hydrogen and oxygen are always combined in a fixed ratio by mass
Explanation and discussion
Question 430· Water· JAMB
Washing soda crystals, Na₂CO₃·10H₂O, lose water of crystallisation when exposed to air. They are described as
Show answer
Answer: B. efflorescent
Explanation and discussion
Question 431· Water· JAMB
Pure water at normal atmospheric pressure boils at
Show answer
Answer: D. 100 °C
Explanation and discussion
Question 432· Water· JAMB
Find the percentage of water by mass in Na₂CO₃·10H₂O. [Na = 23, C = 12, O = 16, H = 1]
Show answer
Answer: C. 62.9%
Explanation and discussion
Question 433· Water· JAMB
A substance that absorbs moisture from the air and dissolves in it to form a solution is described as
Show answer
Answer: D. deliquescent
Explanation and discussion
Question 434· Water· JAMB
Water dissolves many ionic substances because its molecules are
Show answer
Answer: C. polar
Explanation and discussion
Question 435· Water· JAMB
Which of the following is hygroscopic and is used as a drying agent?
Show answer
Answer: C. concentrated tetraoxosulphate(VI) acid
Explanation and discussion
Question 436· Water· JAMB
In the treatment of town water, alum is added to
Show answer
Answer: A. make suspended particles coagulate and settle
Explanation and discussion
Question 437· Water· JAMB
Hard water forms scum with soap because
Show answer
Answer: D. calcium and magnesium ions react with the soap
Explanation and discussion
Question 438· Water· JAMB
Soap forms scum in hard water because of dissolved
Show answer
Answer: A. calcium and magnesium ions
Explanation and discussion
Question 439· Water· JAMB
Permanent hardness of water can be removed by
Show answer
Answer: B. adding washing soda
Explanation and discussion
Question 440· Water· JAMB
Water is called a universal solvent because it
Show answer
Answer: C. dissolves a wide range of substances
Explanation and discussion

Practise Chemistry like the real exam. A timed CBT, your score, and the topics to fix.

Start a Chemistry test

JAMB Chemistry questions

The solubility of KNO₃ is 60 g per 100 g of water at 40 °C and 30 g per 100 g at 20 °C. What mass of crystals forms when 160 g of saturated solution at 40 °C is cooled to 20 °C?

A saturated solution is one that:

Which process exchanges the Ca²⁺ and Mg²⁺ ions in hard water for Na⁺ ions?

In water treatment, suspended particles are removed mainly by

Temporary hardness of water is removed by

Temporary hardness of water is caused by dissolved:

Ion-exchange resins soften water by

Which substance removes both temporary and permanent hardness of water?

Water is regarded as a compound because

Washing soda crystals, Na₂CO₃·10H₂O, lose water of crystallisation when exposed to air. They are described as

Pure water at normal atmospheric pressure boils at

Find the percentage of water by mass in Na₂CO₃·10H₂O. [Na = 23, C = 12, O = 16, H = 1]

A substance that absorbs moisture from the air and dissolves in it to form a solution is described as

Water dissolves many ionic substances because its molecules are

Which of the following is hygroscopic and is used as a drying agent?

In the treatment of town water, alum is added to

Hard water forms scum with soap because

Soap forms scum in hard water because of dissolved

Permanent hardness of water can be removed by

Water is called a universal solvent because it