Chapters
Chapter 8: Water
Exercise-I [Page 107]
Selina solutions for Concise Chemistry Class 8 ICSE Chapter 8 Water Exercise-I [Page 107]
Name the four main sources of water.
State the importance of water cycle in nature.
Why is water very precious for all living being ?
Name the two gases from which water is formed. What is the chemical composition of these two gases in water ?
Give the molecular formula of water ?
What is the effect on boiling point of water when pressure is increased.
What is the effect on boiling point of water when impurity is added.
Give reason:
Water is used as a cooling agent.
Give reason of Water pipes burst in severe winter.
Give reason for It is difficult to cook in hills compared to plain.
Give reason of Ice floats on water.
Give reason for Sea water does not freeze at 0°C.
How does anomalous expansion of water help aquatic organisms in cold climates ?
Exercise-II [Page 115]
Selina solutions for Concise Chemistry Class 8 ICSE Chapter 8 Water Exercise-II [Page 115]
Explain the term of Solution .
Explain the term of Solute.
Explain the term of Solvent.
What is meant by Unsaturated.
What is meant by Saturated .
What is meant by Supersaturated solutions.
How do the solubility of a solid and a gas affected by Increase in temperature.
How do the solubility of a solid and a gas affected by Increase in pressure.
Differentiate between Solution and suspension
Differentiate between Suspension and colloid.
Define: ‘water of crystallisation’. Give two examples with formulae.
Give two examples of Hydrated substances.
Give two examples of Crystalline anhydrous substances.
Give two examples of Drying agent.
Give two examples for Deliquescent substance.
Give two examples for Efflorescent substance.
Give two example of Colloid.
Give two example of Solvent other than water.
What do you observe when Blue vitriol is heated ?
What do you observe when Washing soda is exposed to air ?
What do you observe when Blue litmus solution is added to water ?
Give reason for Silica gel pouches are kept in unused water bottle.
Give reason for Table salt becomes moist during rainy season.
Give reason On opening a bottle of a cold drink, a fizz sound is heard.
Give balanced chemical equation for the reaction of water with Sodium .
Give balanced chemical equation for the reaction of water with Iron .
Give balanced chemical equation for the reaction of water with Carbon dioxide.
Give balanced chemical equation for the reaction of water with Sodium oxide.
What is metal activity series ?
Name the gas produced when steam is passed over hot coke.
Name the gas produced when chlorine is dissolved in water and exposed to sunlight.
Name the gas produced when a piece of calcium is added to water.
Name the gas produced when fossil fuel is burnt.
Exercise-III [Pages 120 - 121]
Selina solutions for Concise Chemistry Class 8 ICSE Chapter 8 Water Exercise-III [Pages 120 - 121]
Define the Soft water.
Define the Hard water.
Name the compound responsible for temporary hardness.
Name the compound responsible for permanent hardness of water.
Suggest one method for the removal along with the reaction for temporary hardness.
Suggest one method for the removal along with the reaction for permanent hardness of water.
Name three water borne diseases.
What are the main causes of water pollution ? How can it be controlled ?
Give reason of Alcohol is mixed with water and is used in car radiator.
Give reason of Icebergs float on ocean water.
Give reason of Carbonated drinks are bottled under high pressure.
Objective Type Questions [Page 121]
Selina solutions for Concise Chemistry Class 8 ICSE Chapter 8 Water Objective Type Questions [Page 121]
Fill in the blank.
Water has...................... density and .................. volume at 4°C.
Fill in the blank.
Freezing mixture contains........and .............
Fill in the blank.
The solubility of a gas in water.............. with rise in temperature and.......................with rise in pressure.
Fill in the blank.
.................... is the purest form of natural water.
Fill in the blank :
Use of excessive....................y farmers causes water pollution.
Fill in the Blank :
Boiling removes the ................ hardness of water.
Fill in the blank:
Water turns the colour of anhydrous copper sulphate.................
Fill in the blank:
Water turns the colour of anhydrous copper sulphate ...........
Match the statements in column A with that in column B.
| Column A | Column B |
| (a) deliquescent substance | (1) sodium bicarbonate |
| (b) hygroscopic substance | (2) magnesium chloride |
| (c) efflorestance substance | (3) conc. sulphuric acid |
| (d) substance causing temporary hardness | (4) washing soda |
Give one word for the following statement:
Water fit for human consumption .
Give one word for the following statement:
The harmful substances dissolved in water .
Give one word for the following statement :
The change of states of water from one form to another .
Give one word for the following statement:
The gaseous form of water found in air .
Give one word for the following statement:
A mixture of common salt and ice .
Give one word for the following statement:
A substance which does not contain water .
Give one word for the following statement:
A property due to which a substance absorbs water without dissolving.
Give one word for the following statement:
Water molecules in loose chemical combination with other substances.
Multiple Choice Questions [Page 121]
Selina solutions for Concise Chemistry Class 8 ICSE Chapter 8 Water Multiple Choice Questions [Page 121]
Two gases found dissolved in natural water are
oxygen and carbon dioxide
hydrogen and oxygen
sulphur dioxide and hydrogen
chlorine and ammonia
Temporary hardness of water can be removed by
filtering
boiling
loading
none of the above
The ultimate source of all water on the earth is
oceans and seas
spring and wells
rivers and lakes
rain
Colloids have the particle size range between
10-7 to 10-10 m
10-10 to 10-12 m
10-7 to 10-5 m
10-12 to 10-15 m
Chapter 8: Water
Selina solutions for Concise Chemistry Class 8 ICSE chapter 8 - Water
Selina solutions for Concise Chemistry Class 8 ICSE chapter 8 (Water) include all questions with solution and detail explanation. This will clear students doubts about any question and improve application skills while preparing for board exams. The detailed, step-by-step solutions will help you understand the concepts better and clear your confusions, if any. Shaalaa.com has the CISCE Concise Chemistry Class 8 ICSE solutions in a manner that help students grasp basic concepts better and faster.
Further, we at Shaalaa.com provide such solutions so that students can prepare for written exams. Selina textbook solutions can be a core help for self-study and acts as a perfect self-help guidance for students.
Concepts covered in Concise Chemistry Class 8 ICSE chapter 8 Water are Dissolution of Salts in Water, Concept of Universal Solvent, Solutions, Suspensions, Colloids, Differentiate Unsaturated/Saturated and Supersaturated Solutions, Water of Crystallisation, Hydrated and Anhydrous Substances, Hygroscopic, Reactivity of Metals with Cold Water, Hot Water and Steam (With Products Formed)., Hard and Soft Water and Methods of Softening of Hard Water, Removing hardness of water by boiling or by treating with washing soda, Concept for Water.
Using Selina Class 8 solutions Water exercise by students are an easy way to prepare for the exams, as they involve solutions arranged chapter-wise also page wise. The questions involved in Selina Solutions are important questions that can be asked in the final exam. Maximum students of CISCE Class 8 prefer Selina Textbook Solutions to score more in exam.
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