Exercise I on Water Class 6 Concise Chemistry ICSE Solutions Ch-7. In this article you would learn how to solve Exercise I on Water with hint and reason. Visit official Website CISCE for detail information about ICSE Board Class-6.
Exercise I on Water Class 6 Concise Chemistry ICSE Solutions
| Board | ICSE |
| Publications | Selina Publication |
| Subject | Chemistry |
| Class | 6th |
| Chapter-7 | Water |
| Book Name | Concise |
| Topics | Solution of Exercise I |
| Academic Session | 2025-2026 |
Exercise I on Water
Objective Type Questions
Que-1: The water content in human body is:
(i)70%
(ii)75%
(iii)80%
(iv)90%
Ans- 70%
Reason: About 70% of the human body is made up of water, which is essential for various body functions.
Que-2: The purest form of natural water is:
(i)sea water
(ii)river water
(iii)rain water
(iv)lake water
Ans- rain water
Reason — Rain water is the purest form of water, formed by the evaporation of water from water bodies on the earth’s surfaces, followed by condensation of its vapour. The only impurities present in rain water are dust and dissolved, non-poisonous gases of air.
Que-3: When the water vapour changes into tiny droplets of water near the ground, it is called:
(i)mist
(ii)dew
(iii)fog
(iv)frost
Ans- fog
Reason — Fog is formed when the water vapour changes into tiny droplets of water near the ground.
Que-4: Water is a:
(i)compound
(ii)element
(iii)mixture
(iv)none of the above
Ans- compound
Reason — Water is made up of hydrogen and oxygen chemically combined in a fixed ratio (H₂O).
Que-5: Which of the following is a source of underground water?
(i)Rivers
(ii)Lakes
(iii)Ponds
(iv)Springs
Ans- Springs
Reason: Springs are places where underground water naturally comes out to the Earth’s surface.
Que-6: Under normal conditions, water exists as a:
(i)solid
(ii)liquid
(iii)gas
(iv)all of the above
Ans- liquid
Reason: At ordinary temperature and pressure, water remains in the liquid state.
Que-7: The most suitable source of water for domestic and industrial uses is :
(i)sea water
(ii)river water
(iii)spring water
(iv)rain water
Ans- river water
Reason: It is usually cleaner and contains fewer impurities than surface water.
One word answer
Que-1: What are the three states of water?
Ans- The three states of water are :
(i) Solid – Ice
(ii) Liquid – Water
(iii) Gas – Water Vapour
Short Answer Questions
Que-1: Name:
(i) Two major sources of natural water
(ii) Two sources of surface water
(iii) Two underground sources of water.
Ans- (i) Two major sources of natural water:
(a)Rain
(b)Snow
(ii) Two sources of surface water:
(a)Rivers
(b)Lakes
(iii) Two underground sources of water:
(a)Wells
(b)Springs.
Que-2: List three major impurities present in river water.
Ans- Three major impurities present in river water are:
(i)Suspended soil and sand particles
(ii)Dissolved salts and minerals
(iii)Germs
Que-3: Answer the following questions in brief:
(i) In which form is water present in the atmosphere?
(ii) Which source of water contains the highest concentration of salt in it ?
(iii) What possible impurities does rain water contain?
(iv) What is water table?
Ans- (i)Water vapour
(ii)Sea water
(iii)Dust particles, smoke, and dissolved gases
(iv)The upper level of underground water is called the water table.
Que-4: Find the percentage of water in the following:
(i) Rice and wheat grains
(ii) Eggs
(iii) Tomatoes
(iv) Bread
(v) Watermelon
Ans- (i) Rice and wheat grains — 10%
(ii) Eggs — 74%
(iii) Tomatoes — 95%
(iv) Bread — 35%
(v) Watermelon — 92%
Long Answer Questions
Que-1: What is water cycle? State two important roles of water cycle in nature.
Ans- The water cycle is the continuous circulation of water between the earth’s surface and the atmosphere through the processes of evaporation, condensation, and precipitation. Water from oceans, rivers, lakes, and plants evaporates into the atmosphere, condenses to form clouds, and then falls back to the earth as rain, snow, or hail.
Two Important Roles of the Water Cycle in Nature
1. Maintains the supply of fresh water:
The water cycle continuously replenishes rivers, lakes, ponds, and underground water sources, providing fresh water for plants, animals, and human beings.
2. Maintains the balance of water in nature:
It ensures that water is constantly recycled between the atmosphere, land, and water bodies, helping to maintain ecological balance and support life on Earth.
Que-2: Give reason:
(i)Rain water is considered the purest form of natural water.
(ii)Spring water is pure enough for drinking but unsuitable for laboratory use.
(iii)The taste of spring water differs at different places.
(iv)Ice, water and steam are considered to have the same chemical composition.
Ans- (i) Rain water is formed by the evaporation of water from oceans, rivers, and lakes. During evaporation, dissolved salts and other impurities are left behind. Therefore, rain water is the purest natural form of water.
(ii) Spring water contains dissolved minerals and salts. These are not harmful for drinking but can interfere with chemical experiments. Hence, it is unsuitable for laboratory use.
(iii) Spring water dissolves different kinds and amounts of minerals and salts from the rocks and soil through which it passes. Therefore, its taste varies from place to place.
(iv) Ice, water, and steam are three physical states of the same substance, water. All of them contain only H₂O molecules; only their physical state differs. Hence, they have the same chemical composition.
Que-3: How are the following formed ?
(i) fog
(ii) mist
(iii) dew
(iv) frost.
Ans- (i) Fog is formed when the water vapour present in the air cools and condenses into tiny water droplets near the surface of the Earth. These droplets remain suspended in the air, reducing visibility.
(ii) Mist is formed when warm, moist air cools and water vapour condenses into very fine droplets suspended in the air. It is thinner than fog and does not reduce visibility as much.
(iii) Dew is formed when the temperature of the ground and objects on it falls below the dew point at night. Water vapour in the air condenses on cool surfaces such as grass, leaves, and metal objects as tiny droplets of water.
(iv) Frost is formed when the temperature falls below 0°C. Water vapour in the air changes directly into tiny ice crystals on cold surfaces without first becoming liquid water. This process is called deposition.
— : End of Exercise I on Water Class 6 Concise Chemistry ICSE Solutions :–
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