Water ICSE Class-6th Concise Selina Chemistry Solutions
Water ICSE Class-6th Concise Selina Chemistry Solutions Chapter-7. We Provide Step by Step Answer of Objective, True False , Fill in the blanks , Match the following , Short/Long Answer Type of Exercise-7 Water. Visit official Website CISCE for detail information about ICSE Board Class-6.
Water ICSE Class-6th Concise Selina Chemistry Solutions Chapter-7
(a) Three major sources of natural water
(b) Four sources of surface water.
(c) Two underground sources of water.
(a) Three major sources of natural water :
Surface water (sea water)
Above surface water (rain)
Underground water (springs)
(b) Four sources of surface water sources :
- Ocean water
- River water
- Lake water
(c) Two sources of underground water :
- Well water
- Spring water
Answer the following questions in short:
(a) In which form is water present in the atmosphere ?
(b) Which source of water contains the highest concentration of salt in it ?
(c) Why is rain water considered the purest form of natural water?
(d) What possible impurities does rain water contain ?
(e) What is water table ?
(f) Why is spring water pure enough for drinking but unsuitable for laboratory use ?
(g) Why the taste of spring water differs at different places ?
(a) Water is present in the form of water vapours in the atmosphere.
(b) Sea water contains highest concentration of salt.
(c) Rain water is the purest form of water as it is distilled water i.e. water from surface of earth has evaporated and then vapours condense in the atmosphere.
(d) The impurities present in rain water are dust and dissolved gases like oxygen, nitrogen and carbon dioxide and these gases are not poisonous, rain water is safe for drinking.
(e) Level of ground water is called water table.
(f) Spring water is free from suspended impurities and germs (harmful bacteria) as water has been filtered through different layers of soil and is fit for drinking. Spring water contains dissolved impurities which are due to the nature of soil surrounding the spring and cannot be used for laboratory purposes, where distilled water free from impurities is needed.
(g) Spring water contains unsolved impurities which have entered the water from surrounding soil and soil impurities (salts) differ from place to place. Hence taste of water differs from place to place.
List three major impurities present in river water.
Three major impurities present in river water :
- Suspended impurities like clay and sand particles.
- Harmful bacteria.
- Mineral salts.
Give the percentage of water in the following :
(a) Rice and wheat grains
(e) Water melon
Percentage of water in :
(a) Rice — 3 % to 4% Wheat grain — 3% to 4%
(b) Eggs —75%
(c) Tomatoes — 95%
(d) Bread —25%
(e) Water melon — 97%
What are the three states of water ?
Three states of water are :
- Ice (solid)
- Liquid (water)
- Gaseous (steam)
Why are ice, liquid water and steam considered to have the same chemical substance ?
Ice, liquid water and steam have same composition i.e. 2 parts hydrogen and one part oxygen by volume and same formula H2O, can be easily transformed from one state to other by heating or cooling.
How is a cloud formed ?
Water from the surface of earth, lakes, seas, rivers, formed by plants (transpiration) etc. evaporates and rises high up in the atmosphere and condense into water droplets and collect to form cloud.