{"id":22815,"date":"2022-06-04T09:00:29","date_gmt":"2022-06-04T03:30:29","guid":{"rendered":"https:\/\/cbselibrary.com\/?p=22815"},"modified":"2023-01-25T11:05:35","modified_gmt":"2023-01-25T05:35:35","slug":"selina-concise-chemistry-class-6-icse-solutions-water","status":"publish","type":"post","link":"https:\/\/cbselibrary.com\/selina-concise-chemistry-class-6-icse-solutions-water\/","title":{"rendered":"Selina Concise Chemistry Class 6 ICSE Solutions – Water"},"content":{"rendered":"
ICSE Solutions<\/a>Selina ICSE Solutions<\/a>ML Aggarwal Solutions<\/a><\/p>\n APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 6 Chemistry. You can download the Selina Concise Chemistry ICSE Solutions for Class 6 with Free PDF download option. Selina Publishers Concise Chemistry for Class 6 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.<\/p>\n Selina Class 6 Chemistry ICSE Solutions<\/a>Physics<\/a>Biology<\/a>Maths<\/a>Geography<\/a>History & Civics<\/a><\/p>\n Selina Concise ICSE Solutions for Class 6 Chemistry Chapter\u00a0 7\u00a0 Water<\/strong><\/p>\n POINTS TO REMEMBER<\/strong><\/p>\n EXERCISE-I<\/strong><\/span><\/p>\n Question 1.<\/strong><\/span> (a)<\/strong> Three major sources of natural water Answer:<\/strong><\/span><\/p>\n (a)<\/strong> Three major sources of natural water :<\/p>\n (b)<\/strong> Four sources of surface water sources :<\/p>\n (c)<\/strong> Two sources of underground water :<\/p>\n Question 2.<\/strong><\/span> (a)<\/strong> In which form is water present in the atmosphere ? Answer:<\/strong><\/span><\/p>\n (a)<\/strong> Water is present in the form of water vapours in the atmosphere. Question 3.<\/strong><\/span> Question 4.<\/strong><\/span> (a)<\/strong> Rice and wheat grains Answer:<\/strong><\/span> (a)<\/strong> Rice \u2014 3 % to 4% Wheat grain \u2014 3% to 4% Question 5.<\/strong><\/span> Question 6.<\/strong><\/span> Question 7.<\/strong><\/span> Question 8.<\/strong><\/span> Question 9.<\/strong><\/span> (a) fog<\/strong> Answer:<\/strong><\/span><\/p>\n (a) Fog :<\/strong> When water vapours change into tiny droplets of water near the ground, fog is formed. EXERCISE-II<\/strong><\/span><\/p>\n Question 1.<\/strong><\/span> (a)<\/strong> Two chemicals used to destroy germs present in water. Answer:<\/strong><\/span> (b)<\/strong> Two diseases are cholera, dysentry. Question 2.<\/strong><\/span> (a)<\/strong> Why is river water unfit for drinking? Answer:<\/strong><\/span><\/p>\n (a)<\/strong> River water contains mineral salts, suspended impurities like clay, sand particles, organic matter and bacteria and is not fit for drinking. Question 3.<\/strong><\/span> (a)<\/strong> Sterilisation Answer:<\/strong><\/span><\/p>\n (a) Sterilisation :<\/strong> The process of removal of microorganisms including bacterial spores from water to avoid water borne diseases is known as sterilisation. Question 4.<\/strong><\/span> Question 5.<\/strong><\/span> Importance of water for animals:<\/strong><\/p>\n Question 6.<\/strong><\/span> Question 7.<\/strong><\/span> Question 8.<\/strong><\/span>\n
\n<\/li>\n
\n(i)<\/strong> restoring the lost water from earth\u2019s surface
\n(ii)<\/strong> in controlling the climatic conditions.<\/li>\n
\n(i)<\/strong> boiling,
\n(ii)<\/strong> sterilisation
\n(iii)<\/strong> exposing to air and sunlight
\n(iv)<\/strong> by chemical treatment like chlorination or ozonisation.<\/li>\n
\nName:<\/strong><\/p>\n
\n(b)<\/strong> Four sources of surface water.
\n(c)<\/strong> Two underground sources of water.<\/p>\n\n
\n
\n
\nAnswer the following questions in short:<\/p>\n
\n(b)<\/strong> Which source of water contains the highest concentration of salt in it ?
\n(c)<\/strong> Why is rain water considered the purest form of natural water?
\n(d)<\/strong> What possible impurities does rain water contain ?
\n(e)<\/strong> What is water table ?
\n(f)<\/strong> Why is spring water pure enough for drinking but unsuitable for laboratory use ?
\n(g)<\/strong> Why the taste of spring water differs at different places ?<\/p>\n
\n(b)<\/strong> Sea water contains highest concentration of salt.
\n(c)<\/strong> 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.
\n(d)<\/strong> 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.
\n(e)<\/strong> Level of ground water is called water table.
\n(f)<\/strong> 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.
\n(g)<\/strong> 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.<\/p>\n
\nList three major impurities present in river water.
\nAnswer:<\/strong><\/span>
\nThree major impurities present in river water :<\/p>\n\n
\nGive the percentage of water in the following :<\/p>\n
\n(b)<\/strong> Eggs
\n(c)<\/strong> Tomatoes
\n(d)<\/strong> Bread
\n(e)<\/strong> Water melon<\/p>\n
\nPercentage of water in :<\/p>\n
\n(b)<\/strong> Eggs \u201475%
\n(c)<\/strong> Tomatoes \u2014 95%
\n(d)<\/strong> Bread \u201425%
\n(e)<\/strong> Water melon \u2014 97%<\/p>\n
\nWhat are the three states of water ?
\nAnswer:<\/strong><\/span>
\nThree states of water are :<\/strong><\/p>\n\n
\nWhy are ice, liquid water and steam considered to have the same chemical substance ?
\nAnswer:<\/strong><\/span>
\nIce, liquid water and steam have same composition i.e. 2 parts hydrogen and one part oxygen by volume and same formula H2<\/sub>O, can be easily transformed from one state to other by heating or cooling.<\/p>\n
\nHow is a cloud formed ?
\nAnswer:<\/strong><\/span>
\nWater 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.<\/p>\n
\nWhat is water cycle ? What is its importance ?
\nAnswer:<\/strong><\/span>
\nWater cycle : The change of water from one form to another in nature which results in continuous circulation of water from earth\u2019s surface to the atmosphere and from the atmosphere back to the earth\u2019s surface is called water cycle.
\nImportance of water cycle:<\/strong><\/p>\n\n
\nHow are the following formed ?<\/p>\n
\n (b) mist<\/strong>
\n (c) dew<\/strong>
\n (d) frost<\/strong><\/p>\n
\n(b) Mist:<\/strong> When tiny droplets of water remain suspended in air it is called mist.
\n(c) Dew :<\/strong> When the water vapour condenses on cold objects like grass, leaves and flowers in winter in the form of tiny droplets of water called dew.
\n(d) Frost:<\/strong> When the dew freezes it is called frost.<\/p>\n
\nName:<\/strong><\/p>\n
\n(b)<\/strong> Two diseases which spread through impure water.
\n(C)<\/strong> A chemical used for loading.
\n(d)<\/strong> Two substances which add taste to water.
\n(e)<\/strong> Two household methods to get safe drinking water.<\/p>\n
\n(a)<\/strong> Two chemicals used to kill germs in water are:<\/p>\n\n
\n(c)<\/strong> Chemical used for loading is potash alum.
\n(d)<\/strong> Minerals and carbon dioxide gas adds taste to water.
\n(e)<\/strong> Methods to get safe drinking water:<\/p>\n\n
\nAnswer in brief:<\/strong><\/p>\n
\n(b)<\/strong> Why is tap water a mixture?
\n(c)<\/strong> What is mineral water?
\n(d)<\/strong> What is the purpose of adding bleaching powder to water supplied to the town?
\n(e)<\/strong> How is chemically pure water obtained in the laboratory?
\n(f)<\/strong> how is water in swimming pool kept free a germs?<\/p>\n
\n(b)<\/strong> Tap water contains, minerals, air, chlorine and other dissolved impurities that varies from place to place, therefore it is a mixture.
\n(c)<\/strong> Mineral water is pure water fit for drinking. It is collected from natural source and contains air, minerals and salts free from suspended impuiities, harmful bacteria and germs.
\n(d)<\/strong> Adding bleaching powder to water, kills germs and harmful bacteria and viruses present in water.
\n(e)<\/strong> Chemically pure water for laboratories is obtained-by distillation. Distilled water does not contain any salt or mineral
\n(f)<\/strong> Water in swimming pool kept free from infections and germs by chlorination i.e. treating water with chlorine gas.<\/p>\n
\nDefine:<\/strong><\/p>\n
\n(b)<\/strong> Sedimentation
\n(c)<\/strong> Loading
\n(d)<\/strong> Aeration<\/p>\n
\n(b) Sedimentation :<\/strong> The setting of suspended solid matter at the bottom of a liquid is called sedimentation.
\n(c) Loading :<\/strong> The process of adding a chemical to an impure liquid in order to increase the speed of sedimentation of suspended particles is called loading.
\n(d) Aeration :<\/strong> To kill harmful micro-organisms present in filtered water, air underpressure is blown into the filtered water. This process is called aeration.<\/p>\n
\nWhat is potable water ? List four characteristics of potable water.
\nAnswer:<\/strong><\/span>
\nPotable water :<\/strong> Water fit for drinking purposes is called potable water.
\nFour characters of drinking water :<\/strong><\/p>\n\n
\nWhy is water important for plants and animals ?
\nAnswer:<\/strong><\/span>
\nImportance of water for plants:<\/strong><\/p>\n\n
\nCrops need water for their growth. Water in the form of rain, washes the dust and smoke deposited on leaves by vehicles and helps the stomata in exchanging gases.<\/li>\n<\/ol>\n\n
\nWhat are the three methods of removing germs from natural water. Explain.
\nAnswer:<\/strong><\/span>
\nThree methods to remove germs :<\/strong><\/p>\n\n
\nName the steps involved in the purification of drinking water supplied in cities and towns.
\nAnswer:<\/strong><\/span>
\nThe water source for our towns and cities are river, lakes or underground water which contains suspended and dissolved impurities.
\nTo remove these impurities steps involved are :<\/strong><\/p>\n\n
\nWater is now potable i.e. safer for drinking and supplied to homes.<\/li>\n<\/ol>\n
\nWhat is the taste of distilled water ? Why is it not potable?
\nAnswer:<\/strong><\/span>