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"Water" question number distribution across years
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JAMB questions for "Chemistry :: Water"
Q1

Permanent hardness of water can be removed by

A

adding caustic soda

B

boiling

C

amphoteric

D

hygroscopic

E

Answer: A

Water
Q2

Substances employed as drying agents are usually 

A

efflorescent

B

acidic

C

amphoteric

D

hygroscopic

E

Answer: D

Water
Q3

The acid used in electrolysis of water is dilute

A

HNO3

B

CH2COOH

C

H2SO4

D

HCl

E

Answer: C

Water
Q4

Water can be obtained as the only product during the 

A

combustion of hydrocarbons

B

neutralization of an acid by a base

C

combustion of hydrogen

D

electrolysis of brine

E

Answer: C

Water
Q5

In the course of purifying water for town supply, the water is passed through large settling tanks containing sodium aluminate (III) to remove

A

large particles

B

germ

C

fine particles

D

odour

E

Answer: A

Water
Q6

When a few drops of water is added to a blue anhydrous cobalt (II) chloride, the colour changes to 

A

white

B

pink

C

red

D

blue

E

Answer: B

Water
Q7

When temporary hard water is boiled for some time in a kettle, the inner surface of the kettle becomes coated with a deposit of 

A

calcium trioxocarbonate (IV)

B

calcium tetraoxosulphate (VI)

C

aluminium trioxocarbonate (IV)

D

calcium hydrogentrioxocarbonate (IV)

E

Answer: A

Water
Q8

A good drying agent should be

A

effervescent

B

hygroscopic

C

efflorescent

D

deliquescent

E

Answer: B

Water
Q9
Hardness of water is caused by the presence of the ions of
A
calcium and magnesium
B
calcium and sodium
C
magnesium and silver
D
sodium and potassium
E

Answer: A

Water
Q10
When a salt loses its water of crystallization to the atmosphere on exposure, the process is said to be
A
efflorescence
B
deliquescence
C
effervescence
D
flourescence
E

Answer: A

Water
Q11
The chemical used for coagulation in water purification is
A
copper tetraoxosulphate (VI)
B
sodium tetraoxosulphate (VI)
C
aluminium tetraoxosulphate (VI)
D
calcium tetraoxosulphate (VI)
E

Answer: C

Water
Q12
A side effect of soft water is that
A
it gives offensive taste
B
excess calcium is precipitated
C
it attacks lead contained in pipes
D
it encourages the growth of bacteria
E

Answer: C

Water
Q13
The method that can be used to convert hard water to soft water is
A
chlorination
B
passage over activated charcoal
C
the use of an ion-exchange resin
D
aeration
E

Answer: C

Water
Q14
8.0g of an element X reacted with an excess of copper (II) tetraoxosulphate (VI) solution to deposit 21.3g of copper. The correct equation for the reaction is   [Cu = 64]
A
X(s) + CuSO4(aq) → 2Cu(s) + XSO4(aq)
B
X(s) + 2CuSO4(aq) → Cu(s) + X(SO4)2(aq)
C
2X(s) + CuSO4(aq) → Cu(s) + X2(SO4)(aq)
D
2X(s) + 3CuSO4(aq) → 3Cu(s) + X2(SO4)3(aq)
E

Answer: D

Water
Q15
Potassium tetraoxomanganate (VII) is often added to impure water to
A
reduce organic impurities
B
reduce inorganic impurities
C
destroy bacteria and algae
D
remove permanent hardness
E

Answer: C

Water
Q16
A major process involved in the softening of hard water is the
A
conversion of a soluble calcium salt to its trioxocarbonate (IV)
B
decomposition of calcium trioxocarbonate(IV)
C
conversion of an insoluble calcium salt to its trioxocarbonate (IV)
D
oxidation of calcium atoms to its ions
E

Answer: A

Water
Q17
A solid that absorbs water from the atmosphere and forms an aqueous solution is
A
Hydrophilic
B
efflorescent
C
deliquescent
D
hygroscopic
E

Answer: C

Water
Q18
Water can be identified by the use of
A
anhydrous copper (II) tetraoxosulphate (VI)
B
anhydrous sodium trioxocarbonate (IV)
C
potassium heptaoxocarbonate (VII)
D
copper (II) trioxcarbonate (IV)
E

Answer: A

Water
Q19
The phenomenon whereby sodium trioxocarbate (IV) decahydrate loses some of its water of crysallization on exposure to the atmosphere is known as
A
deliquescence
B
hygroscopy
C
effervescence
D
efffloresence
E

Answer: D

Water
Q20
Water for town supply is chlorinated to make it free from
A
bad odour
B
bacteria
C
temporary hardness
D
permanent hardness
E

Answer: B

Water
Q21
A sample of temporary hard water can be prepared in the labouratory by
A
dissolving calcium chloride in distilled water.
B
saturating lime water with carbon(IV) oxide.
C
saturated distilled water with calcium hydroxide.
D
dissolving sodium hydrogentrioxocarbonate (VI) in some distilled water.
E

Answer: B

Water
Q22
A blue solid T, which weighed 5.0g was placed on a table, After 8 hours, the resulting pink solid was found to weigh 5.5g. It can be infered that substance T
A
is deliquescent
B
is hydroscopic
C
has some molecules of water of crystallization
D
is efflorescent
E

Answer: A

Water
Q23
Calcium hydroxide is added in the treatment of town water supply to
A
kill bacteria in the water
B
facilitate coagulaon of organic particles
C
facilitate sedimentation
D
improve the taste of the water
E

Answer: D

Water
Q24
A hydrated salt of formular MSO4 xH2O contains 45.3% by mass of water of crysallization. Calculate the value of X   [M = 56, S = 32, O = 16, H = 1]
A
3
B
5
C
7
D
10
E

Answer: C

Water
Q25
In the purification of town water supply, alum is used principally to
A
kill bacteria
B
control the pH of water
C
improve the taste of the water
D
coagulate small particles of mud
E

Answer: D

Water
Q26
Which of the following water samples will have the highest titre value when titrated for the Ca2+ ions using soap solution?
A
Permanently hard water after boiling.
B
Temporary hard water after boiling.
C
Rain water stored in a glass jar for two years.
D
Permanently hard water passed through permutit.
E

Answer: A

Water
Q27
Which of the following contains an efflorescent, a deliquescent and a hygroscopic substance respectively?
A
Na2SO4, concentrated H2SO4, CaCl2
B
Na2CO3.H2O, FeSO4.7HO2, concentrated H2SO4
C
Na2CO3.10H2O, FeCl3, concentrated H2SO4
D
Concentrated H2SO4, FeSO4,7HO2,MgCl2
E

Answer: C

Water
Q28
If 80 g each of X and Y are taken up in 100 g of water at 353 K we shall have
A
only 10g of X undissolved
B
only 16g of Y undissolved
C
10g of X and 16g of Y undissolved
D
all X and Y dissolved
E
all X and Y undissolved

Answer: B

Water
Q29
The boiling points of water, ethanol, toluene and buton-2-ol are 373. 0K, 383.6K and 372.5K respectively. Which liquid has the highest vapour pressure at 323.0K?
A
Water
B
Toluene
C
Ethanol
D
Butan-2-ol
E
None

Answer: C

Water
Q30
When pollen grains are suspended in water and viewed through a microscope, they appear to be in a state of constant but erratic motion. This is due to
A
convection currents
B
small changes in pressure
C
small changes in temperature
D
a chemical reaction between the pollen grains and water
E
the bombarment of the pollen grains by molecules of water

Answer: E

Water
Q31
Which of the following substances is the most abundant in the universe?
A
Carbon
B
Air
C
Water
D
Oxygen
E
Hydrogen

Answer: C

Water
Q32
Water is said to be "hard" if it
A
easily forms ice
B
has to be warmed before sodium chloride dissolves in it
C
forms an insoluble scum with soap
D
contains nitrates
E
contains sodium ions

Answer: C

Water
Q33
2.5g of a hydrated barium salt gave on heating 2.13g of the anhydrous salt. given that the relative molecular mass of the anhydrous salt 208, the number of molecules of water of crystallization of the barium salt
A
10
B
7
C
5
D
2
E
1

Answer: D

Water
Q34
The scale formation in a kettle used for boiling water is caused by the presence in water of
A
calcium sulphate
B
calcium carbonate
C
calcium hydrogen carbonate
D
calcium hydroxide
E
magnesium sulphate

Answer: C

Water
Q35
An efflorescent compound is a substance that
A
absorbs water from their air without dissolving in it.
B
is capable of giving off coloured luminosity.
C
gives out water to the atmosphere.
D
absorbs water from their air and dissolves in it.
E
gives out its water of crystallization on heating.

Answer: C

Water
Q36
5.00g of hydrated salt of barium when heated to a constant weight gave 4.26g of anhydrous salt with a molecular weight of 208. The number of molecules of water of crystalline in the hydrated salt is
A
10
B
7
C
5
D
2
E
1

Answer: D

Water
Q37
A sample of hard water contains some calcium sulphate and calcium hydrogen carbonate. The total hardness may therefore be removed by;
A
boiling the water
B
adding excess calcium hydroxide
C
adding a calculated amount of calcium hydroxide
D
adding sodium carbonate
E
adding magnesium hydroxide

Answer: D

Water
Q38
Which one of the following changes is physical?
A
adding iron filling to aerated water
B
adding sodium metal to water
C
cooling a solution of iron (II) sulphate to obtain the hydrated salt
D
cooling water to obtain ice
E
burning the domestic gas (utilgas) for cooking

Answer: D

Water
Q39
The normal boiling point of a liquid is defined as
A
the temperature at which its vapour pressure equals the atmospheric pressure
B
the temperature at which bubbles begins to form
C
the temperature at which the vapour pressure equals 1 atmosphere
D
the temperature at which the rate of condensation of vapour equals the rate of vapourization of the liquid
E
the temperature at which the space above the liquid is saturated

Answer: A

Water