Water notes

Short Notes

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Very Short Notes

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Identify the error in the given statements. Circle the incorrect word and write the correct word in the blank.

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Give Reasons

Answer the following Questions

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Water True and False

Write True False for each statement, Rewrite the false statements 1. River water is the most impure form of water.

2. Use of pesticides in excess, causes water pollution.

3. All living beings contain 10% to 20% of water.

4. Dissolved gases in water are necessary for respiration.

5. Cholera is a disease caused due to water pollution

Answers

Write True False for each statement, Rewrite the false statements

1. False (River water is the pure form of water)

2. True

3. False (All living beings contain 70% to 80% of water)

4. True

5. True

1. Groundwater contains dissolved salt and is free from suspended impurities. Answer :True

2. The molecules of ice, water and steam are different. Answer :False

3. Rainwater gets polluted while falling down. Answer :False

4. Groundwater contains suspended impurities. Answer :False

5. Digestion of food in the stomach takes place with the help of water. Answer :True

6. Typhoid is a waterborne disease caused by virus. Answer :False

7. Trees should be planted as they help in causing rainfall. Answer :True

8. Flood causes soil erosion. Answer :True
   

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1. Water helps in excretion . Answer :True

2. Potable water is not fi t for drinking. Answer :False

3. With increase in pressure, the boiling point of water decreases. Answer :False
   

4. Dissolving a covalent compound like glucose results in a chemical change. Answer :False

5. Water or any other liquid in which solute dissolves is called solvent. Answer :True

6. A solution of mixture salt and rock . Answer :False

7. The rate of formation of water vapour is called evaporation . Answer :True

8. Water is used as a coolant in power genera Answer :True

9. The boiling point of water decreases with increase in pressure. Answer :False

10. A solution is a mixture of solvent and solute . Answer :True

11. The crystallised water can be easily removed by heat . Answer :True

12. Magnesium reacts with steam vigorously and forms a red solid of magnesium oxide and hydrogen gas Answer :False

13. Hard water is not suitable for drinking and cooking purposes. Answer :True

Water Fill in the Blanks

Class 6

Fill in the Blanks

1. edit ________________ (Rainwater/Surface water) is the purest form of water. Answer : Rainwater

2. edit The density of water is maximum at ________________. Answer : 4°C

3. edit ________________ is the amount of heat energy required to raise the temperature of a liquid by 1°C. Answer : Specific heat capacity

4. edit Large amount of water is also given out by the leaves of plants during ________________. Answer : transpiration

5. edit Water helps in the excretion of waste from the body in the form of ________________, urine or while breathing. Answer : sweat

6. edit Water is very important for ________________ of seeds. Answer : germination

7. edit About ________________ of the fresh water is present in rivers, lakes, springs, ponds, etc. Answer : one-third

8. edit In ________________ state, water exists as snow or frost. Answer : solid

9. edit Water exists as ________________ or ________________ in gaseous state. Answer : water vapour, steam

10. edit The density of water is ________________ at 4 degree Celsius. Answer : maximum

11. edit Water regulates the body ________________ of plants and animals. Answer : temperature

12. edit Water acts as a ________________ in powerhouses which generate electricity. Answer : coolant

13. edit Solubility of a solute ________________ on increasing the temperature. Answer : increases

14. edit A solution is said to be ________________ when it can dissolve more of the solute at a particular temperature. Answer : unsaturated

15. edit ________________ is an infection in the small intestine caused by a bacterium. Answer : Cholera

16. edit The addition of unwanted and harmful substances to water is called ________________. Answer : water pollution

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Fill in the blanks with anxwers

(a) Water is a universal; solvent.

(b) Rainwater is the purest form of natural water.

(c) Sand and dust are suspended impurities in water.

(d) Sea water has high concentration of salt (impurity).

(e) Water covers nearly 4 / 5 th of the surface of the earth.

(f) Evaporation of rain water leaves NO residue.

(g) Potash alum is the chemical added to water to remove the tiny suspended particles.

(h) A solution is a uniform mixture of a solute and a solvent.

(i) Ice, water and steam have different physical states but are chemically identical.

(j) Boiling kills most of the germs in water.

(k) The elements present in the molecules of water are hydrogen and oxygen.

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1. Water is essential for running .......................... power plants.1

2. A sample of water which is fit for human .......................... is called potable water.

3. A solution which cannot dissolve more of solute is called ............................. solution.

4. Distilled water is ...................................... water.

5. Fish die in ................................. ponds during summer season

Answers

Fill in the blanks

1. hydroelectric

2. consumption

3. saturated

4. pure

5. shallow

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Class 8

1. Fill in the blanks:

(a) Water has maximum density and minimum volume at 4°C.

(b) Freezing mixture contains ice and salt.

(c) The solubility of a gas in water increases with rise in temperature and decreases with rise in pressure.

(d) Rain water is the purest form of natural water.

(e) Use of excessive fertilizers by farmers causes water pollution.

(f) Boiling removes the temporary hardness of water.

(g) Water turns the colour of anhydrous copper sulphate blue.

(h) Water turns the colour of anhydrous copper sulphate scum.

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Class 9

Fill in the blanks:

1. Water forms about ________ of human body and almost ________ of some plants.
   

2. ________ is used for drinking purpose.
   

3. A solution of iodine in alcohol known as ________.
   

4. Anhydrous substance lack their ________.
   

5. Concentrated ________ remove water of molecules from blue vitriol. It is a ________ agent.
   

6. Washing soda contains ________ molecules of water of crystallisation.
   

7. The higher the temperature of the air, the ________ the efflorescence.
   

8. Land and sea breeze are caused by ________ property of water. [specific heat capacity/latent heat of vaporisation]
   

9. ________ gas is more soluble in water. [nitrogen/oxygen]
   

10. Air is the example of ________ solution.
    

11. The boiling point of water ________ due to the presence of dissolved impurities. [increases/decreases]
    

12. Water molecule has _______ bonding in it. [ionic, covalent]

(i) 65%, 95% (ii) Soft water (iii) tincture of iodine (iv) water of crystalisation (v) sulphuric acid, dehydrating (vi) ten (vii) higher (viii) specific heat capacity (ix) oxygen (x) gaseous (xi) increases (xii) covalent

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A.L. Lavoisier, in the year (i) ________ showed that water is a compound of (ii) ________ and (iii) ________ atoms combined together in the ratio of (iv) ________.

Answers ;

(i) 1781, (ii) hydrogen, (iii) oxygen, (iv) 2 : 1

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