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Lakhmir Singh solutions for Class 9 Science chapter 2 - Is Matter Around Us Pure

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Lakhmir Singh Class 9 Chemistry - Science Part 2

Class 9 Chemistry - Science Part 2 - Shaalaa.com

Chapter 2: Is Matter Around Us Pure

Very Short AnswersShort AnswersLong AnswersMultiple Choice QuestionsHots Questions

Lakhmir Singh solutions for Class 9 Science Chapter 2 Exercise Very Short Answers, Short Answers, Long Answers, Multiple Choice Questions, Hots Questions [Pages 36 - 60]

Very Short Answers | Q 1 | Page 56

State whether the following statement is true or false :

Milk is a pure substance.

  • True

  • False

Very Short Answers | Q 2 | Page 56

Name three mixtures found in nature.

Very Short Answers | Q 3 | Page 56

Which of the following is a mixture ?

Salt, Air, Water, Alum, Sugar

Very Short Answers | Q 4 | Page 56

Name one metal and one non-metal which exist as liquids at room temperature.

Very Short Answers | Q 5 | Page 56

Name a metal which is soft and a non-metal which is hard.

Very Short Answers | Q 6 | Page 59

Name a non-metal which is a good conductor of electricity.

Very Short Answers | Q 7 | Page 56

Name a liquid which can be classified as a pure substance and conducts electricity.

Very Short Answers | Q 8 | Page 56

Name one solid, one liquid and one gaseous non-metal.

Very Short Answers | Q 9.1 | Page 56

Name the property which allows metals to be hammered into thin sheets.

Very Short Answers | Q 9.2 | Page 56

Name the property which enables metals to be drawn into wires.

Very Short Answers | Q 10 | Page 56

Which type of elements, metals or non-metals, show the property of brittleness ?

Very Short Answers | Q 11 | Page 56

What is meant by saying that metals are malleable and ductile ?

Very Short Answers | Q 12 | Page 56

What is meant by saying that non-metals are brittle ?

Very Short Answers | Q 13 | Page 56

What is meant by saying that metals are sonorous ?

Very Short Answers | Q 14 | Page 56

What is meant by saying that metals are lustrous ?

Very Short Answers | Q 15 | Page 56

What is the general name of the materials which contain at least two pure substances and show the properties
of their constituents ?

Very Short Answers | Q 16 | Page 57

‘‘The properties of the product are different from those of the constituents''. State whether this statement best describes an element, a compound or a mixture.

Very Short Answers | Q 17 | Page 57

Name one element, one compound and one mixture.

Very Short Answers | Q 18 | Page 57

What is the major difference between a solution and an ordinary mixture ?

Very Short Answers | Q 19 | Page 57

What name is given to those elements which are neither good conductors of electricity like copper nor insulators like sulphur ?

Very Short Answers | Q 20.1 | Page 57

Fill in the following blanks with suitable words :

An element is made up of only one kind of ........

Very Short Answers | Q 20.2 | Page 57

Fill in the following blanks with suitable words :

Brine is a ..............whereas alcohol is a...............

Very Short Answers | Q 20.3 | Page 57

Fill in the following blanks with suitable words :

Brass is an alloy which is considered a ..............

Very Short Answers | Q 20.4 | Page 57

The three important metalloids are.............................. and ..........................

Very Short Answers | Q 20.5 | Page 57

Fill in the following blanks with suitable words :

The elements which are sonorous are called ..........................

Short Answers | Q 21 | Page 57

Classify the following into elements and compounds :

  1. H2O
  2. He
  3. Cl2
  4. CO
  5. Co
Short Answers | Q 22 | Page 57

Classify the following as elements or compounds :
Iron, Iron sulphide, Sulphur, Chalk, Washing soda, Sodium, Carbon, Urea

Short Answers | Q 23 | Page 57

What elements do the following compounds contain ?

Sugar, Common salt

Short Answers | Q 24 | Page 57

What are pure substances ? Give two examples of pure substances.

Short Answers | Q 25 | Page 57

What are the two types of pure substances? Give one example of each type.

Short Answers | Q 26 | Page 57

Which of the following are ‘pure substances’ ?
Ice, Milk, Iron, Hydrochloric acid, Calcium oxide, Mercury, Brick, Wood, Air

Short Answers | Q 27 | Page 57

What is the other name for impure substances ? Give two examples of impure substances.

Short Answers | Q 28 | Page 57

Which of the following substances are elements ?

Water, Salt, Mercury, Iron, Marble, Diamond, Wood, Nitrogen, Air, Graphite, Hydrogen, Oxygen, Sugar, Chlorine

Short Answers | Q 29 | Page 57

State three reasons why you think air is a mixture and water is a compound.

Short Answers | Q 30 | Page 57

Name two solid, two liquid and two gaseous elements at the room temperature.

Short Answers | Q 31 | Page 57

Explain why, hydrogen and oxygen are considered elements whereas water is not considered an element.

Short Answers | Q 32 | Page 57

What are the three groups into which all the elements can be divided ? Name two elements belonging to each group.

Short Answers | Q 33 | Page 57

State two physical properties on the basis of which metals can be distinguished from non-metals.

Short Answers | Q 34 | Page 57

Compare the properties of metals and non-metals with respect to

  1. alleability
  2. ductility
  3. electrical conductivity.
Short Answers | Q 35 | Page 57

State any two properties for believing that aluminium is a metal.

Short Answers | Q 36.1 | Page 57

Give reason why copper metal is used for making electric wires.

Short Answers | Q 36.2 | Page 36

Give reason why graphite is used for making elecrode in a dry cell.

Short Answers | Q 37 | Page 57

How would you confirm that a colourless liquid given to your is pure water ?

Short Answers | Q 38 | Page 57

Choose the solutions from among the following mixtures :

Soil, Sea-water, Air, Coal, Soda-water

Short Answers | Q 39 | Page 57

Is air a mixture or a compound ? Give three reasons for your answer.

Short Answers | Q 40 | Page 57

Give two reasons for supposing that water is a compound and not a mixture.

Short Answers | Q 41 | Page 57

Define a compound. Give two points of evidence to show that sodium chloride is a compound.

Short Answers | Q 42 | Page 57

Define a mixture. Give two points of evidence to show that sugar solution is a mixture.

Short Answers | Q 44 | Page 57

List five characteristics by which compounds can be distinguished form mixtures.

Short Answers | Q 45 | Page 57

Explain why, a solution of salt in water is considered a mixture and not a compound.

Short Answers | Q 46 | Page 58

State one property in which a solution of sugar in water resembles a mixture of sugar and sand, and one property in which it differs from it.

Short Answers | Q 47 | Page 58

You are given two liquids, one a solution and the other a compound. How will you distinguish the solution from the compound ?

Short Answers | Q 48 | Page 58

Name a non-metal :

  1. which is lustrous
  2. which is required for combustion
  3. whose one of the allotrophic forms is a  good conductor of electricity. Name the allotrope.
  4. other than carbon which shows allotropy
  5. which is known to form the largest number of compounds
Short Answers | Q 49.1 | Page 58

Name a metal which can be easily cut with a knife.

Short Answers | Q 49.2 | Page 58

Name a metal which forms amalgams.

Short Answers | Q 49.3 | Page 58

Name a metal which has no fixed shape.

Short Answers | Q 49.4 | Page 58

Name a metal which has a low melting point.

Short Answers | Q 49.5 | Page 58

Name a metal which is yellow in colour.

Short Answers | Q 50 | Page 58

Which of the following are not compounds ?

Chlorine gas, Potassium chloride, Iron powder, Iron sulphide, Aluminium foil, Iodine vapour, Graphite, Carbon monoxide, Sulphur powder, Diamond

Long Answers | Q 51.1 | Page 58

State the main points of difference between homogeneous and heterogeneous mixtures.

Long Answers | Q 51.2 | Page 58

Classify the following materials as homogeneous mixtures and heterogeneous mixtures :

Soda-water, Wood, Air, Soil, Vinegar, Alcohol and water mixture, Petrol and water mixture, Chalk and water mixture, Sugar and water mixture, Copper sulphate solution.

Long Answers | Q 52.1 | Page 58

What is meant by (i) elements (ii) compounds, and (iii) mixtures ?Write down the names of two elements, two compounds and two mixtures.

Long Answers | Q 52.2 | Page 58

Classify the following into elements, compounds and mixtures :

arble, Air, Gold, Brass, Sand, Diamond, Graphite, Petroleum, Common salt, Sea-water, Chalk

Long Answers | Q 53.1 | Page 58

What are (i) metals (ii) non-metals, and (iii) metalloids ? Give two examples each of metals, non-metals and metalloids.

Long Answers | Q 53.2 | Page 58

Classify the following into metals, non-metals and metalloids:
Silicon, Mercury, Diamond, Sulphur, Iodine, Germanium, Sodium, Carbon, Magnesium, Copper, Boron, Helium

Long Answers | Q 54.1 | Page 58

What is a mixture ? Give two example of mixtures.

Long Answers | Q 54.2 | Page 58

What is meant by (i) homogeneous mixtures, and (ii) heterogeneous mixtures ? Give two examples of homogeneous mixtures and two of heterogenous mixtures.

Long Answers | Q 55.1 | Page 58

What are the three general classes of matter ? Give one example of each type.

Long Answers | Q 55.2 | Page 58

Draw a flow-chart for the schematic representation of different types of matter.

Multiple Choice Questions | Q 56 | Page 58

Which of the following is not an element ?

  • graphite

  • germanium

  • silica

  • silicon

Multiple Choice Questions | Q 57 | Page 58

Which of  the following are compounds ?

  1. CO
  2. No
  3. NO
  4. Co
  • (i) and (ii)

  • (ii) and (iii)

  • (i) and (iii)

  • (i) and (iii)

  • (ii) and (iv)

Multiple Choice Questions | Q 58 | Page 58

One of the following substances is neither a good conductor of electricity nor an insulator. This substance is :

  • chromium

  • germanium

  • gallium

  • potassium

Multiple Choice Questions | Q 59 | Page 59

Which of the following is not a mixture ?

  • kerosene

  • air

  • alcohol

  • petrol

Multiple Choice Questions | Q 60 | Page 59

The element which is not common between the compounds called baking soda and soda ash is

  • sodium

  • hydrogen

  • oxygen

  • carbon

Multiple Choice Questions | Q 61 | Page 59

“Is malleable and ductile” best describes :

  • a solution

  • a metal

  • a compound

  • a non-metal

Multiple Choice Questions | Q 62 | Page 59

Which one of the following is not a metalloid ?

  • boron

  • silicon

  • gallium

  • germanium

Multiple Choice Questions | Q 63 | Page 59

The elements which normally exist in the liquid state are :

  • bromine and iodine

  • mercury and chlorine

  • iodine and mercury

  • bromine and mercury

Multiple Choice Questions | Q 64 | Page 59

When a mixture of iron powder and sulphur powder is heated strongly to form iron sulphide, then heat energy is :

  • released

  • first absorbed and then released

  • absorbed

  • neither absorbed nor released

Multiple Choice Questions | Q 65 | Page 59

The property/properties which enable copper metal to be used for making electric wires is/are :

  • copper metal is malleable and ductile

  • copper metal is a good conductor of electricity

  • copper metal is ductile and has low electrical resistance

  • copper metal is sonorous and an excellent conductor of electricity

Multiple Choice Questions | Q 66 | Page 59

On the basis of composition of matter, milk is considered to be :

  • a pure substance

  • an impure substance

  • an element

  • a compound

Multiple Choice Questions | Q 67 | Page 59

Which of the following statements are true for pure substances ?

  1. pure substances contain only one kind of particles
  2. pure substances may be compounds or mixtures
  3. pure substances have the same composition throughout
  4. pure substances can be exemplified by all elements other than nickel
  • (i) and (ii)

  • (i) and (iii)

  • (iii) and (iv)

  • (ii) and (iii)

Multiple Choice Questions | Q 68 | Page 59

Which of the following are homogeneous in nature ?

  1. ice
  2. wood
  3. soil
  4. air
  • (i) and (iii)

  • (ii) and (iv)

  • (i) and (iv)

  • (iii) and (iv)

Multiple Choice Questions | Q 69 | Page 59

Two chemical substances X and Y combine together to form a product P which contains both X and Y X + Y 􀁯 P
X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following  statements concerning X, Y and P are correct ?

  1. P is a compound
  2. X and Y are compounds
  3. X and Y are elements
  4. P has a fixed composition
  • (i), (ii) and (iii)

  • (i), (ii) and (iv)

  • (ii), (iii) and (iv)

  • (i), (iii) and (iv)

Multiple Choice Questions | Q 70 | Page 59

Which of the following does not have a fixed melting point/boiling point ?

  • gold

  • ethanol

  • air

  • oxygen

Multiple Choice Questions | Q 71 | Page 59

In the following set of substances, one item does not belong to the set. Select this item and explain why it does not belong to the set :

Hydrogen, Oxygen, Steam, Chlorine

Multiple Choice Questions | Q 72 | Page 59

Iron powder and sulphur powder were mixed together and divided into two parts A and B. When part A was heated strongly over a burner, then a substance C was formed. The part B was, however, not heated at all. When dilute hydrochloric acid was added to substance C, then gas D was evolved and when dilute hydrochloric acid was added to part B then gas E was evolved.

  1. What type of substance is B ?
  2. What type of substance is C ?
  3. Name the gas (i) D, and (ii) E ?
  4. State one characteristic property of gas D.
  5. Write one test to identify gas E.
Hots Questions | Q 73 | Page 60

There are three substances X, Y and Z. The substance X does not have a fixed melting point or boiling point and it still shows the individual properties of its constituents. The substance Y is a pure substance which occurs in nature as such. The substance Y has a fixed melting point and boiling point but it cannot be broken down into simpler substances by any chemical means. The substance Z is also a pure substance whose properties are entirely different from those of its constituents. The substance Z can, however, be divided by electrolysis into two substances which belong to the same class of substances as Y.

  1. What type of substance could X be ? Name one substance like X.
  2. What type of substance could Y be ? Name one substance like Y.
  3. What type of substance could Z be ? Name one substance like Z.
  4. Which process involves absorption or release of an appreciable amount of energy : formation of substance X or formation of substance Z ?
  5. Name the three groups into which all the substances like Y are divided on the basis of their properties.
Hots Questions | Q 74 | Page 60

There is a large group of materials P which can be divided into three groups Q, R and S on the basis of their properties. The substances belonging to group Q can be solids, liquids or gases. The solids belonging to group Q are usually electrical insulators. Most of the substances of group R are solids which are good conductors of electricity. The substances belonging to group S are neither insulators like Q nor good conductors like R. The properties of S are intermediate between those of Q and R.

  1. What could the group of materials P be ?
  2. Name the substances Q. Give two examples of such substances.
  3. Name the substances R. Write two examples of such substances.
  4. Name the substances S. Give two examples of such substances.
  5. Out of Q, R and S, which substances are malleable and ductile ?
Hots Questions | Q 75 | Page 60

A, B and C are all liquids. Liquid A has a comparatively low boiling point. On heating, liquid A vaporises completely without leaving behind any residue. Liquid A is being used increasingly as a fuel in motor vehicles either alone or by mixing with petrol. Liquid B has a very high boiling point. It also vaporises completely on heating, without leaving any residue. Liquid B is a conductor of electricity and used in making thermometers. Liquid C has a moderate boiling point. On heating, liquid C vaporises leaving behind a white solid D which is used in cooking vegetables. The condensation of vapours from C give a liquid E which turns anhydrous CuSO4 to blue.

(a) Which liquid could be an element ? Name this element.

(b) Which liquid could be a mixture ? Name this mixture.

(c) Which liquid could be a compound ? Name this compound.

(d) What could the solid D be ?

(e) What do you think is liquid E ?

Lakhmir Singh solutions for Class 9 Science Chapter 2 Exercise Very Short Answers, Short Answers, Long Answers, Multiple Choice Questions, Hots Questions [Pages 79 - 83]

Very Short Answers | Q 1.1 | Page 79

Out of a colloid, solution and a suspension :

which one has the smallest particles ?

Very Short Answers | Q 1.2 | Page 79

Out of a colloid, solution and a suspension :

which one has the largest particles ?

Very Short Answers | Q 2 | Page 79

What is the name of the clear liquid formed when a solid dissolves in a liquid ?

Very Short Answers | Q 3 | Page 79

Which of the two will scatter light : soap solution or sugar solution ? Why ?

Very Short Answers | Q 4 | Page 79

State whether colloidal solutions are homogeneous or heterogeneous.

Very Short Answers | Q 5 | Page 79

What is the most common way of expressing the concentration of a solution ?

Very Short Answers | Q 6 | Page 79

How much water should be added to 15 grams of salt to obtain 15 per cent salt solution ?

Very Short Answers | Q 7 | Page 79

How much water should be mixed with 12 mL of alcohol so as to obtain 12 % alcohol solution ?

Very Short Answers | Q 8 | Page 79

Choose the correct answer.

A 5 per cent sugar solution means that :

  • 5 g of sugar is dissolved in 95 g of water.

  • 5 g of sugar is dissolved in 100 g of water.

Very Short Answers | Q 9 | Page 79

Choose the correct answer.

A 15% alcohol solution means :

  • 15 mL alcohol and 85 mL water.

  • 15 mL alcohol and 100 mL water.

Very Short Answers | Q 10 | Page 79

Calculate the concentration of a solution which contains 2.5 g of salt dissolved in 50 g of water.

Very Short Answers | Q 11 | Page 79

What is the concentration of a solution which contains 16 g of urea in 120 g of solution ?

Very Short Answers | Q 12 | Page 79

A solution contains 5.6 mL of alcohol mixed with 75 mL of water. Calculate the concentration of this solution.

Very Short Answers | Q 13 | Page 79

If 25 mL of acetone is present in 150 mL of its aqueous solution, calculate the concentration of solution.

Very Short Answers | Q 14 | Page 79

What happens when the temperature of a saturated sugar solution is increased ?

Very Short Answers | Q 15 | Page 79

Which of the following contains less solute at a given temperature and pressure ? Unsaturated solution or Saturated solution.

Very Short Answers | Q 16 | Page 79

State one instance where water undergoes a physical change and one in which it undergoes a chemical change.

Very Short Answers | Q 17.1 | Page 79

State whether the following statement is true or false :

Bread is an example of solid foam.

  • True

  • False

Very Short Answers | Q 17.2 | Page 79

State whether the following statement is true or false :

Sponge is an example of solid sol.

Very Short Answers | Q 18 | Page 80

Choose one term from the following which includes the other three :

aerosol, emulsion, colloid, sol

Very Short Answers | Q 19 | Page 80

Which of the following is a sol ?

Shaving cream, Milk, Fog, Soap solution, Hairspray

Very Short Answers | Q 20.1 | Page 80

Fill in the following blank :

Milk is a .................... solution but vinegar is a .................... solution.

Very Short Answers | Q 20.2 | Page 80

Fill in the following blank :

A colloid is a ..............mixture and its components can be separated by the technique known as ...............

Short Answers | Q 21.1 | Page 80

Define solute.

Short Answers | Q 21.2 | Page 80

Define solvent.

Short Answers | Q 22 | Page 80

What is the difference between solutions and colloids ?

Short Answers | Q 23 | Page 80

What is the difference between colloids and suspensions ?

Short Answers | Q 24 | Page 80

In what respects does a true solution differ from a colloidal solution ?

Short Answers | Q 25 | Page 80

Classify the following into true solutions and colloidal solutions:

Ink, Salt solution, Starch solution, Blood, Sugar solution

Short Answers | Q 26 | Page 80

How will you test whether a given solution is a colloidal solution ?

Short Answers | Q 27 | Page 80

Explain what happens when a beam of light is passed through a colloidal solution.

Short Answers | Q 28 | Page 80

Explain what happens when a beam of light is passed through a colloidal solution.

Short Answers | Q 29 | Page 80

How will you differentiate between a suspension and a colloid ?

Short Answers | Q 30 | Page 80

You have been given a suspension and a solution. How could you tell the difference between them by their appearance ?

Short Answers | Q 31 | Page 80

Which of the following will show Tyndall effect ? Why ?

  1. Salt solution
  2. Starch solution
  3. Milk
  4. Copper sulphate solution
Short Answers | Q 32 | Page 80

Name the different types of solutions. Give one example of each.

Short Answers | Q 33 | Page 80

Classify the following into solutions, suspensions and colloids :

Soda-water, Milk, Brine, Blood, Ink, Smoke in air, Chalk water mixture, Milk of Magnesia, Shaving cream, Muddy river water.

Short Answers | Q 34.1 | Page 80

Define Sol and give one example.

Short Answers | Q 34.2 | Page 80

Define Aerosol Give one example.

Short Answers | Q 34.3 | Page 80

Define the Emulsion Give one example.

Short Answers | Q 34.4 | Page 80

Define Foam Give one example.

Short Answers | Q 35 | Page 80

What is meant by the concentration of a solution ?

Short Answers | Q 36 | Page 80

What will happen if a saturated solution is :

  1. heated
  2. cooled
Short Answers | Q 37 | Page 80

21.5 g of sodium chloride dissolves in 60 g of water at 25°C. Calculate the solubility of sodium chloride in water at that temperature.

Short Answers | Q 38 | Page 80

9.72 g of potassium chloride dissolves in 30 g of water at 70°C. Calculate the solubility of potassium chloride at that temperature.

Short Answers | Q 39 | Page 80

Classify the following as physical or chemical changes :

  1. Cooking of food
  2. Boiling of water
  3. Cutting of trees
  4. D0issolving salt in water
  5. Digestion of food
  6. Melting of ice
Short Answers | Q 40.1 | Page 80

Which of the following are physical changes and which are chemical changes ?

  • Physical change

  • Chemical change

Short Answers | Q 40.2 | Page 80

Which of the following are physical changes and which are chemical changes ?

Freezing of water

  • Physical change

  • Chemical change

Short Answers | Q 40.3 | Page 80

Which of the following are physical changes and which are chemical changes ?

 Rusting of iron

  • Physical change

  • Chemical change

Short Answers | Q 40.4 | Page 80

Which of the following are physical changes and which are chemical changes ?

Glowing of an electric bulb

  • Physical change

  • Chemical change

Short Answers | Q 41.1 | Page 80

Classify the following as physical or chemical change :

Formation of curd from milk

  • Physical change

  • Chemical change

Short Answers | Q 41.2 | Page 80

Classify the following as physical or chemical change :

Condensation of steam

  • Physical change

  • Chemical change

Short Answers | Q 41.3 | Page 80

Classify the following as physical or chemical change :

Growth of a plant

  • Physical change

  • Chemical change

Short Answers | Q 41.4 | Page 80

Classify the following as physical or chemical changes :

Breaking of a glass tumbler

  • Physical change

  • Chemical change

Short Answers | Q 42 | Page 80

Separate the following into physical and chemical changes :

Sublimation of a solid, Decomposition of water into hydrogen and oxygen by passing electric current, Formation of clouds, Making a fruit salad from raw fruits, Dissolving carbon dioxide in water

Short Answers | Q 43 | Page 81

Which of the following are physical changes and which are chemical changes ?

Burning of candle wax, Melting of candle wax, Mixing of iron filings and sand, Burning of wood, Breaking a piece of chalk, Burning a piece of paper, Cutting a piece of paper

Short Answers | Q 44 | Page 81

The ‘sea water’ can be classified as a homogeneous mixture as well as a heterogeneous mixture ? Comment.

Short Answers | Q 45 | Page 81

Which of the following do not exhibit Tyndall effect ?

Starch solution, Sugar solution, Ink, Salt solution, Copper sulphate solution, Ammonium chloride solution, Fog, Smoke, Car exhausts.

Long Answers | Q 46.1 | Page 81

What is a physical change ? Give two examples of physical changes.

Long Answers | Q 46.2 | Page 81

What is a chemical change ? Give two examples of chemical changes.

Long Answers | Q 47.1 | Page 81

Give the main differences between physical changes and chemical changes.

Long Answers | Q 47.2 | Page 81

Which of the following are chemical changes and which physical ? Give reason.

  1. a glass bottle breaking
  2. coal burning in air
  3. making a cake
  4. wool being knitted into a sweater
Long Answers | Q 48.1 | Page 81

Define solubility of a substance. How does it vary with temperature ?

Long Answers | Q 48.2 | Page 81

What do you understand by the statement " the solubility of copper sulphate in water at 20°C is 20.7 g" ?

Long Answers | Q 48.3 | Page 81

What is the effect of temperature on the solubility of solids in liquids ?

Long Answers | Q 49.1 | Page 81

What is meant by a solution ? Give two examples of solutions.

Long Answers | Q 49.2 | Page 81

What is a suspension ? Give two examples of suspensions.

Long Answers | Q 49.3 | Page 81

What is a colloid ? Give two examples of colloids (or colloidal solutions)

Long Answers | Q 50.1 | Page 81

Differentiate between a saturated and an unsaturated solution. How will you test whether a given solution is saturated or not ?

Long Answers | Q 50.2 | Page 81

How would you prepare a saturated solution of sodium chloride in water at 25°C ? What will happen if this  solution is cooled to 10°C ?

Multiple Choice Questions | Q 51 | Page 81

One of the following is a solid foam. This one is :

  • butter

  • bread

  • shaving cream

  • ruby

Multiple Choice Questions | Q 52 | Page 81

Which of the following is not an emulsion ?

  • milk

  • butter

  • face cream

  • shaving cream

Multiple Choice Questions | Q 53 | Page 81

One of the following does not show Tyndall effect. This one is :

  • soap solution

  • ink

  • sugar solution

  • starch solution

Multiple Choice Questions | Q 54 | Page 81

Which one of the following is most likely to exhibit Tyndall effect ?

  • sugar and water mixture

  • potash alum and water mixture

  • chalk powder and water mixture

  • potassium permanganate and water mixture

Multiple Choice Questions | Q 55 | Page 81

Milk of Magnesia is :

  • colloid

  • a true solution

  • a homogeneous mixture

  • a suspension

Multiple Choice Questions | Q 56 | Page 81

Which of the following represents the solubility of sugar in water at 20°C ?

  • 21 g

  • 204 g

  • 37 g

  • 164 g

Multiple Choice Questions | Q 57 | Page 81

Which one of the following is not a chemical change ?

  • formation of curd

  • ripening of banana

  • sublimation of naphthalene

  • corrosion of photo frame

Multiple Choice Questions | Q 58 | Page 81

One of the following liquids will leave behind a residue on heating. This one is :

  • brine

  • bromine

  • mercury

  • alcohol

Multiple Choice Questions | Q 59 | Page 81

Which of the following can be called a suspension ?

  • milk

  • milk of magnesia

  • salt solution

  • vinegar

Multiple Choice Questions | Q 60 | Page 82

One of the following represents the solution of solid in a solid. This one is :

  • boron

  • brass

  • beryllium

  • bread

Multiple Choice Questions | Q 61 | Page 82

The rusting of an iron object is called :

  • corrosion and it is a physical as well as a chemical change

  • dissolution and it is a physical change

  • corrosion and it is a chemical change

  • dissolution and it is a chemical change

Multiple Choice Questions | Q 62 | Page 82

A mixture of sulphur and carbon disulphide is :

  • heterogeneous and shows Tyndall effect

  • homogeneous and shows Tyndall effect

  • heterogeneous and does not show Tyndall effect

  • homogeneous and does not show Tyndall effect

Multiple Choice Questions | Q 63 | Page 82

Tincture of iodine has antiseptic properties. This solution is made by dissolving :

  • iodine in potassium iodide

  • iodine in acetone

  • iodine in water

  • iodine in alcohol

Multiple Choice Questions | Q 64 | Page 82

Which of the following are physical changes ?

  1. melting of iron metal
  2. rusting of iron metal
  3. bending of an iron rod
  4. drawing a wire of iron metal
  • (i), (ii) and (iii)

  • i), (ii) and (iv)

  • (i), (iii) and (iv)

  • (ii), (iii) and (iv)

Multiple Choice Questions | Q 65 | Page 82

Which of the following are chemical changes ?

  1. decaying of wood
  2. burning of wood
  3. sawing of wood
  4. hammering of nail into wood
  • (i) and (ii)

  • (ii) and (iii)

  • (iii) and (iv)

  • (i) and (iv)

Hots Questions | Q 66 | Page 82

Many indigestion mixtures are suspensions. What do the instructions written on the bottle of an indigestion mixture tell us before taking the mixture, and why ?

Hots Questions | Q 67 | Page 82

Three mixtures A, B and C are obtained by stirring three different solids in water taken in separate beakers. When mixture A is allowed to stand for some time, then its particles settle at the bottom of the beaker. When a beam of light is passed through mixture A in a dark room, the path of light becomes visible when observed from the side of the beaker. When mixture B is allowed to stand for a considerable time, even then its particles do not settle down. Mixture B, however, scatters the beam of light just like mixture A. The particles of mixture C do not settle down on keeping and it also does not scatter a beam of light passing through it.

What are the mixtures like A known as ?

What are the mixtures like B known as ?

What are the mixtures like C known as ?

Name the phenomenon exhibited by A and B which occurs on passing a beam of light through them.

Name one mixture each which is like (i) A (ii) B, and (iii) C.

Hots Questions | Q 68 | Page 82

When the solid A is added to water, it dissolves with the evolution of a lot of heat and making little explosions to form two products B and C. The properties of products B and C are entirely different from those of solid A as well as water. Moreover, products B and C cannot be reconverted into solid A and water. When another solid D is added to water, it dissolves with the absorption of a little heat to form a product E which cools down. The product E shows the properties of both, solid D as well as water. Moreover, product E can be converted into solid D and water.

(a) What type of change occurs when solid A is dissolved in water ? Why ?

(b) What type of change occurs when solid D is dissolved in water ? Why ?

(c) Name a metal which you think could behave like solid A. Also name the products B and C.

(d) Name the solid D if it is the one which is used in making ordinary dry cells.

(e) Name the process by which D can be recovered from E.

Hots Questions | Q 69 | Page 82

100 mL of water at room temperature of 25°C is taken in a beaker and a little of solid S is dissolved in it by stirring to obtain a solution X. More and more of solid S is added to the solution with constant stirring, while keeping the temperature of solution constant at 30°C. After some time it is observed that no more solid dissolves in water and at the same time some solid is also left undissolved at the bottom of the beaker.

  1. The contents of beaker are filtered through a filter paper to obtain solution Y in the form of a filtrate.
  2. What name is given to solutions like X ?
  3. What name is given to solutions like Y ?
  4. What will you observe if the solution Y at 30°C is cooled down to 10°C by keeping the beaker in crushed ice ? Why ?
  5. What term is used to denote the amount of solid dissolved in 100 grams of water in a solution lie Y ?
Hots Questions | Q 70 | Page 83

The solubility of ammonium chloride in water at various temperatures is given below :

Temperature : 10°C 20°C 40°C 60°C 80°C
Solubility : 24 g 37 g 41 g 55 g 66 g

What mass of ammonium chloride would be needed to make a saturated solution of ammonium chloride in fifty grams of water at 40°C ?

Lakhmir Singh solutions for Class 9 Science Chapter 2 Exercise Very Short Answers, Short Answers, Multiple Choice Questions, Hots Questions [Pages 105 - 108]

Very Short Answers | Q 1 | Page 105

Name the solvent you would use to separate a mixture of sulphur and carbon.

Very Short Answers | Q 2 | Page 105

Name the process you would use to separate ammonium chloride from a mixture of sodium chloride and ammonium chloride.

Very Short Answers | Q 3 | Page 105

Which method can be used to separate a mixture of naphthalene and common salt ?

Very Short Answers | Q 4 | Page 105

Name the process you would use to separate a mixture of anthracene and copper sulphate ?

Very Short Answers | Q 5 | Page 105

Name the property of any one of the components which can be used for separating the following mixture :

Salt and Camphor

Very Short Answers | Q 6 | Page 105

What type of magnet is fitted on a crane to separate scrap iron objects from a heap of waste materials in factories ?

Very Short Answers | Q 7 | Page 105

Name the property of one of the constituents which can be used to separate a mixture of salt and iodine

Very Short Answers | Q 8 | Page 105

Name the process you would use to separate a mixture of two miscible liquids (like acetone and water).

Very Short Answers | Q 9 | Page 105

What difference in the property of two miscible liquids enables their separation by fractional distillation ?

Very Short Answers | Q 10 | Page 105

Name one pair of substances whose mixture can be separated by fractional distillation.

Very Short Answers | Q 11 | Page 105

Name one pair of liquids which can be separated by using a separating funnel.

Very Short Answers | Q 12.1 | Page 105

State whether the following statement are true or false :

Alcohol can be separated from a mixture of alcohol and water by a separating funnel.

  • True

  • False

Very Short Answers | Q 12.2 | Page 105

State whether the following statement are true or false :

Salt and water can be recovered from an aqueous salt solution by the process of evaporation.

Very Short Answers | Q 13 | Page 105

Name the source from which nitrogen and oxygen are obtained on a large scale.

Very Short Answers | Q 14 | Page 105

Name the process by which the various gases of the air are separated.

Very Short Answers | Q 15 | Page 105

A carpenter wants to separate iron nails from saw-dust. Which method of separation should he choose ?

Very Short Answers | Q 16 | Page 105

Name any two solid substances whose mixture can be separated by sublimation.

Very Short Answers | Q 17 | Page 105

Name one pair of substances whose mixture can be separated completely by distillation.

Very Short Answers | Q 19 | Page 105

How will you separate a mixture of chalk powder and water ?

Very Short Answers | Q 20 | Page 105

Name the process which can be used to recover salt from an aqueous salt solution.

Very Short Answers | Q 21 | Page 105

Name the process which can be used to recover salt from an aqueous salt solution.

Very Short Answers | Q 22 | Page 105

Name the process which is used in milk dairies to separate cream from milk.

Very Short Answers | Q 23 | Page 105

What is the general name of the process by which tea-leaves are separated from prepared tea ?

Very Short Answers | Q 25 | Page 105

Name the process you would use to separate a mixture of water and alcohol.

Very Short Answers | Q 26 | Page 105

What difference in the properties of oil and water enable their separation by a separating funnel ?

Very Short Answers | Q 27 | Page 105

Name the process by which common salt is purified.

Very Short Answers | Q 27.1 | Page 105

Name the process by which common salt is obtained from sea-water.

Very Short Answers | Q 28 | Page 105

Name the process which can be used to purify an impure sample of copper sulphate.

Very Short Answers | Q 29 | Page 105

Name the process by which all the dye can be recovered from black ink.

Very Short Answers | Q 30 | Page 106

Which technique is used in a washing machine to squeeze out water from wet clothes while drying ?

Very Short Answers | Q 31 | Page 106

Which technique can be used to detect and identify traces of poison present in the stomach wash of a person ?

Very Short Answers | Q 32.1 | Page 106

Fill in the following blanks with suitable words :

Miscible liquids are separated by .....................

Very Short Answers | Q 32.2 | Page 106

Fill in the following blanks with suitable words :

Immiscible liquids are separated by using a .....................

Very Short Answers | Q 32.3 | Page 106

Fill in the following blanks with suitable words :

A mixture of kerosene and petrol can be separated by .....................

Very Short Answers | Q 32.4 | Page 106

Fill in the following blanks with suitable words :

The separation of liquids by fractional distillation is based on the difference in their .....................

Very Short Answers | Q 32.5 | Page 106

Fill in the following blanks with suitable words :

The gases of air can be separated by fractional distillation of liquid air because they have different..............

Very Short Answers | Q 32.6 | Page 106

Fill in the following blanks with suitable words :

A heterogeneous mixture of liquid and solid is conveniently separated by...............

Very Short Answers | Q 32.7 | Page 106

Fill in the following blanks with suitable words :

 If a mixture contains iron filings as one of the constituents, it can be separated by using a .......................

Short Answers | Q 33 | Page 106

How will you separate a mixture containing sand and sugar ?

Short Answers | Q 34 | Page 106

What difference in the properties of common salt and sand would enable you to separate a mixture of these two substances ?

Short Answers | Q 35 | Page 106

Describe a method to separate a mixture of common salt and sand.

Short Answers | Q 36 | Page 106

How would you separate a mixture of sugar and salt?

Short Answers | Q 37 | Page 106

How will you separate a mixture of sodium chloride and sand ?

Short Answers | Q 38 | Page 106

Write a method to separate a mixture of sand and potash alum.

Short Answers | Q 39 | Page 106

How would you obtain sodium chloride from a mixture of sodium chloride and sulphur without using water ?

Short Answers | Q 40 | Page 106

How would you separate iodine from a mixture of iodine and common salt ?

Short Answers | Q 41 | Page 106

Describe a method to separate a mixture of camphor and sand.

Short Answers | Q 42 | Page 106

How will you separate a mixture of iron filings and powdered carbon ?

Short Answers | Q 43 | Page 106

How will you separate a mixture of iron fillings and sulphur powder without using carbon disulphide ?

Short Answers | Q 44 | Page 106

How is scrap iron separated from a heap of waste materials in factories?

Short Answers | Q 45 | Page 106

How is the impurity of iron present in several substances removed in industries ?

Short Answers | Q 46 | Page 106

How will you separate iron pins from sand ?

Short Answers | Q 47 | Page 106

How will you separate a mixture of common salt, sulphur powder and sand ?

Short Answers | Q 48 | Page 106

A mixture contains water, kerosene and sand. How will you separate this mixture ?

Short Answers | Q 49 | Page 106

Describe the method of separating a mixture containing common salt, sand and ammonium chloride.

Short Answers | Q 50 | Page 106

How will you separate camphor, common salt and iron nails from their mixture ?

Short Answers | Q 51 | Page 106

You are given a mixture of water, groundnut oil and common salt. How will you separate groundnut oil and common salt from it ?

Short Answers | Q 52 | Page 106

Discuss the method of separating a mixture containing chalk powder, iron filings and naphthalene.

Short Answers | Q 53 | Page 106

Describe the various steps involved in the separation of iodine, iron filings and salt from a mixture.

Short Answers | Q 54 | Page 106

How will you separate a mixture of iron filings, chalk powder and common salt ?

Short Answers | Q 55 | Page 106

How will you separate common salt, sand and iron filings from their mixture ?

Short Answers | Q 56 | Page 106

How will you separate a mixture of kerosene oil and water ? Explain with the help of a labelled diagram.

Short Answers | Q 57 | Page 106

How will you separate water from mustard oil ?

Short Answers | Q 58 | Page 106

How will you separate a mixture of cooking oil (groundnut oil) and water ?

Short Answers | Q 59 | Page 106

How will you separate a mixture of mercury, oil and water ?

Short Answers | Q 60 | Page 106

Describe a method for separating a mixture of iron filings and sulphur powder other than that by using a magnet.

Short Answers | Q 61 | Page 106

How is cream separated from milk ?

Short Answers | Q 62 | Page 106

Explain how, impure copper sulphate can be purified by crystallisation.

Short Answers | Q 63 | Page 106

Which method is better for recovering sugar from sugar solution : evaporation or crystallisation ? Give reason
for your answer.

Short Answers | Q 64 | Page 106

What is chromatography ? State its two applications.

Short Answers | Q 65 | Page 106

Which of the following can be separated by using a separating funnel and which cannot be separated by using a separating funnel ?

  1. water and kerosene mixture
  2. water and acetone mixture

Give reasons for your answer.

Short Answers | Q 66 | Page 106

With the help of a labelled diagram, describe the method of separating ammonium chloride from a mixture of ammonium chloride and common salt. Mention the difference in the properties of ammonium chloride and sodium chloride which has made this separation possible.

Short Answers | Q 67 | Page 107

How can you obtain pure water from a salt-water mixture (or salt-solution) ? Draw a neat and labelled diagram of the apparatus you would use to obtain pure water from a salt-water mixture (or salt-solution).

Short Answers | Q 68 | Page 107

How is water purified on a large scale at water works ? Explain with the help of a labelled diagram. Name the substance which is added to kill germs in the drinking water supply ?

Short Answers | Q 69.1 | Page 107

What is fractional distillation ? What is the use of fractionating column in fractional distillation ?

Short Answers | Q 69.2 | Page 107

Draw a labelled diagram of the fractional distillation apparatus used for separating a mixture of alcohol and water.

Short Answers | Q 70 | Page 107

Explain how, nitrogen , oxygen and argon gases are separated from air.

Multiple Choice Questions | Q 71 | Page 107

A mixture of milk and groundnut oil can be separated by :

  • sublimation

  • evaporation

  • separating funnel

  • filtration

Multiple Choice Questions | Q 72 | Page 107

Which of the following mixture cannot be separated by using water as the solvent ?

  • copper sulphate and sand

  • sand and potash alum

  • sand and sulphur

  • sugar and sand

Multiple Choice Questions | Q 73 | Page 107

The chemical which can be used to separate a mixture of carbon powder and sulphur powder successfully is :

  • carbon dioxide

  • hydrochloric acid

  • hydrogen sulphide

  • carbon disulphide

Multiple Choice Questions | Q 74 | Page 107

The dyes present in fountain pen ink can be separated by the technique of :

  • fractional distillation

  • infrared photography

  • crystallisation

  • chromatography

Multiple Choice Questions | Q 75 | Page 107

Pure copper sulphate can be obtained from an impure sample by the process of :

  • evaporation

  • fractional distillation

  • centrifugation

  • crystallisation

Multiple Choice Questions | Q 76 | Page 107

The material which is added to water during purification process at the water works so as to disinfect it is :

  • potassium permanganate

  • betadine

  • chlorine

  • potash alum

Multiple Choice Questions | Q 77 | Page 107

The technique which is used to separate particles of a solid suspended in a liquid quickly is called :

  • decantation

  • centrifugation

  • sedimentation

  • filtration

Multiple Choice Questions | Q 78 | Page 107

Naphthalene can be separated from sand :

  • by sublimation

  • by distillation

  • by crystallisation

  • by using water as solvent

Multiple Choice Questions | Q 79 | Page 107

Which of the following cannot be separated from air by the process of fractional distillation ?

  • oxygen

  • argon

  • hydrogen

  • nitrogen

Multiple Choice Questions | Q 80 | Page 107

The correct increasing order of the boiling points of liquid oxygen, liquid argon and liquid nitrogen present in liquid air is :

  • nitrogen, oxygen, argon

  • nitrogen, argon, oxygen

  • argon, oxygen, nitrogen

  • oxygen, argon, nitrogen

Multiple Choice Questions | Q 81 | Page 107

The boiling point of liquid argon is :

  •  – 196°C

  • – 183°C

  • –186°C

  • –193°C

Multiple Choice Questions | Q 82 | Page 107

You are given a mixture of iodine in alcohol called tincture iodine. Which method will you use to recover both, iodine as well as alcohol, from this mixture ?

  • evaporation

  • simple distillation

  • fractional distillation

  • crystallisation

Multiple Choice Questions | Q 83 | Page 107

The best way to recover sugar from an aqueous sugar solution is :

  • evaporation to dryness

  • distillation

  • filtration

  • crystallisation

Multiple Choice Questions | Q 84 | Page 107

One of the following does not undergo sublimation. This one is :

  • camphor

  • dry ice

  • silica

  • iodine

Multiple Choice Questions | Q 85 | Page 107

Which one of the following scrap metal cannot be separated by magnetic separation ?

  • nickel

  • cobalt

  • chromium

  • steel

Hots Questions | Q 86 | Page 108

The liquid air has three components X, Y and Z whose boiling points are : –186°C, –183°C and –196°C,
respectively. When liquid air is fed into a tall fractional distillation column from near its bottom and warmed
up slowly :

(a) Which component will be collected from near the bottom of the fraction distillation column ? Why ?

(b) Which component will be collected from the top part of the fractional distillation column ? Why ?

(c) Which component will be collected from the middle part of the fractional distillation column ? Why ?

(d) What could the component X, Y and Z be ?

Hots Questions | Q 87 | Page 108

There are three liquids A, B and C, all having different densities and different boiling points. Liquids A and C are organic in nature whereas liquid B is considered to be inorganic. When liquids A and B are put together in a container, they form a single layer. On the other hand, when, liquids B and C are mixed, they form two separate layers :

(a) Which process will you use to separate a mixture of A and B ?

(b) Which method will you use to separate a mixture of B and C ?

(c) Name the liquids which would behave like (i) A (ii) B and (iii) C.

Hots Questions | Q 88 | Page 108

A solid mixture contains four constituents P, Q, R and S. P consists of tiny grains and it is mixed with
cement for plastering the walls. Q is a white solid which is recovered on a large scale from sea water by the
process of evaporation. R is in the form of tiny particles of a material whose corrosion is called rusting. And
S is a white solid which is used in making ordinary dry cells.

  1. What could P, Q, R and S be ?
  2. How would you separate a mixture containing P, Q, R and S ?
Hots Questions | Q 89 | Page 108

Tincture of iodine is a mixture of two materials X and Y. The material Y has a property that its solid form can be converted directly into vapours on heating by a process called Z.

  1. What could X be ?
  2. What could Y be ?
  3. Name the process Z.
  4. Which process would you use to recover both the components X and Y from tincture of iodine ?
  5. Which process can be used to recover only component Y from tincture of iodine ?
Hots Questions | Q 90 | Page 108

The given mixture contains three constituents A, B and C. The constituent A is a yellow coloured, solid element which dissolves in a liquid D. The constituent B is a blue coloured salt which is insoluble in liquid D but dissolves easily in another liquid E. The constitudent C is a liquid which is used in cooking food and forms a solid fat on hydrogenation.

(a) What do you think could (i) constituent A, and (ii) liquid D be ?

(b) What could (i) constituent B, and (ii) liquid E be ?

(c) What could liquid C be ?

(d) How will you separate the mixture containing A, B and C ?

Chapter 2: Is Matter Around Us Pure

Very Short AnswersShort AnswersLong AnswersMultiple Choice QuestionsHots Questions

Lakhmir Singh Class 9 Chemistry - Science Part 2

Class 9 Chemistry - Science Part 2 - Shaalaa.com

Lakhmir Singh solutions for Class 9 Science chapter 2 - Is Matter Around Us Pure

Lakhmir Singh solutions for Class 9 Science chapter 2 (Is Matter Around Us Pure) 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 CBSE Class 9 Chemistry - Science Part 2 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. Lakhmir Singh textbook solutions can be a core help for self-study and acts as a perfect self-help guidance for students.

Concepts covered in Class 9 Science chapter 2 Is Matter Around Us Pure are Suspension, Separate a Mixture of Two Miscible Liquids, Obtain Different Gases from Air, Obtain Pure Copper Sulphate from an Impure Sample, Is Matter Pure (Introduction, Mixture), Concept of Mixture, Solution, Properties of a Solution, Colloidal Solution, Concentration of a Solution, Obtain Coloured Component (Dye) from Blue/Black Ink, Separate Cream from Milk, Immiscible Liquids, Separate a Mixture of Salt and Ammonium Chloride, Is the Dye in Black Ink a Single Colour, Physical and Chemical Changes, Is Matter Pure (Numerical), Types of Mixtures, What Are the Types of Pure Substances, Elements, Compounds.

Using Lakhmir Singh Class 9 solutions Is Matter Around Us Pure 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 Lakhmir Singh Solutions are important questions that can be asked in the final exam. Maximum students of CBSE Class 9 prefer Lakhmir Singh Textbook Solutions to score more in exam.

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