Applied Chemistry Questions and Answers – Sources, Impurities and Hardness of Water

This set of Applied Chemistry Questions and Answers for Aptitude test focuses on “Sources, Impurities and Hardness of Water”.

1. The quantity of water available for the actual use is _________
a) 10%
b) 5%
c) 0.5%
d) 1%
View Answer

Answer: c
Explanation: The quantity of water available on the earth’s crust is about 80% and the quantity of water available for actual use that is in the form of rivers, tanks is about 0.5%.

2. __________ of water is struck in underground which is not accessibly.
a) 1%
b) 2%
c) 3%
d) 4%
View Answer

Answer: a
Explanation: 96% of the water is struck in the forms of oceans which is too saline to use it directly and 2% is polar ice caps and glaciers and 1% is under ground water.

3. ___________ is the purest form of the water obtained by natural distillation.
a) Under ground water
b) Sea water
c) River water
d) Rain water
View Answer

Answer: d
Explanation: Rain water is the purest form of the water obtained by natural distillation. Some part of the rain water penetrates into the ground and there it will be stored.
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4. Lake water contains more __________ due to the biological oxidation of the organic matter.
a) Oxygen
b) Carbon dioxide
c) Nitrogen
d) Carbon monoxide
View Answer

Answer: b
Explanation: Lake Water contains more amount of carbon dioxide due to the biological oxidation of the organic matter present at the bottom of the lake.

5. The colour and odour of the natural water is due to the presence of the ___________
a) Dissolved organic matter
b) Mud
c) Leaves
d) Other dust particles
View Answer

Answer: a
Explanation: The colour and odour of the natural water is due to the presence of the dissolved organic matter. Dissolved gases like nitrogen, oxygen and carbondioxide are present in lake water.
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6. Deep well water possess the rotten egg smell due to the dissolved ________
a) Sulphide
b) Sulphurous acid
c) Hydrogen sulphide
d) Hydrogen peroxide
View Answer

Answer: c
Explanation: Deep well water possesses the rotten egg smell due to the dissolved hydrogen sulphide. The underground water is colourless and odourless.

7. Well water in wells located in the areas of oil and gases will contain __________
a) Ethane
b) Methane
c) Carbon
d) Nitrogen
View Answer

Answer: b
Explanation: Well water in wells located in the areas of oil and gases will contain methane gas. When rain water falls on earth and flows on the earth and becomes impure.
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8. Surface water appears turbid due to the presence of the __________ which remains suspended in the water.
a) Impurities
b) Oxygen
c) Nitrogen
d) Water plants
View Answer

Answer: a
Explanation: Surface water appears turbid due to the presence of the impurities which remains suspended in the water. The dissolved gases make the water into bad odour.

9. Which of the following is the suspended impurity?
a) Iron hydroxide
b) Dust
c) Mud
d) Nitrogen
View Answer

Answer: a
Explanation: The nitrogen is the dissolved impurity. The suspended impurities are iron hydroxide, silica are the inorganic impurities which decomposes the organic impurities.
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10. The suspended impurities is negligible due to the filtering action of __________
a) Water plants
b) Dissolved impurities
c) Soil
d) Dissolved gases
View Answer

Answer: c
Explanation: The suspended impurities are negligible due to the filtering action of the soil. The soil filters all the suspended impurities like silica and iron hydroxide.

11. How many types of absorbed impurities in water are there mainly?
a) 2
b) 3
c) 4
d) 5
View Answer

Answer: c
Explanation: There are four types of impurities in water are there. They are suspended impurities, dissolved gases, dissolved mineral salts and bacterial impurities.

12. In dissolved mineral salts ___________ gets converted into the bicarbonates by the action of carbondioxide by water.
a) Carbonate of calcium
b) Carbonates of magnesium
c) Carbonates of calcium and magnesium
d) Neither carbonates of calcium nor magnesium
View Answer

Answer: c
Explanation: In dissolved mineral salts, the carbonates of calcium and magnesium get converted into the bicarbonates by the action of the carbondioxide by water.

13. ___________ water contains more soluble salts than the surface water.
a) Sea water
b) Rain water
c) Underground water
d) Tank water
View Answer

Answer: c
Explanation: Sea water and tank water comes under the surface water and the under ground water contains more soluble salts than the surface water.

14. Amino acids comes under _________ impurity.
a) Dissolved impurity
b) Colloidal impurity
c) Dissolved gases
d) Bacterial impurities
View Answer

Answer: b
Explanation: Amino acids comes under the colloidal impurities. All the gases like nitrogen, oxygen and carbondioxide comes under the dissolved gases.

15. Chemical composition of the lake water is _________
a) Constant
b) Not constant
c) Some times constant
d) Cannot be determined
View Answer

Answer: a
Explanation: Chemical composition of lakes is constant. It has a high quantity of organic matter and lesser quantity dissolved minerals.

Sanfoundry Global Education & Learning Series – Applied Chemistry.

To practice all areas of Applied Chemistry for Aptitude test, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]

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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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