Lakhmir Singh solutions for Chemistry [English] Class 9 chapter 2 - Is Matter Around Us Pure [Latest edition]

State whether the following statement is true or false :

Milk is a pure substance.

Name three mixtures found in nature.

Which of the following is a mixture ?

Salt, Air, Water, Alum, Sugar

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

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

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

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

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

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

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

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

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

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

What is meant by saying that metals are sonorous ?

What is meant by saying that metals are lustrous ?

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

‘‘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.

Name one element, one compound and one mixture.

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

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

Fill in the following blanks with suitable words :

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

Fill in the following blanks with suitable words :

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

Fill in the following blanks with suitable words :

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

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

Fill in the following blanks with suitable words :

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

Classify the following into elements and compounds :

1. H₂O
2. He
3. Cl₂
4. CO
5. Co

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

What elements do the following compounds contain ?

Sugar, Common salt

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

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

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

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

Which of the following substances are elements ?

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

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

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

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

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

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

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

1. alleability
2. ductility
3. electrical conductivity.

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

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

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

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

Choose the solutions from among the following mixtures :

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

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

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

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

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

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

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

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.

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

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

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

Name a metal which forms amalgams.

Name a metal which has no fixed shape.

Name a metal which has a low melting point.

Name a metal which is yellow in colour.

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

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

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.

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

Classify the following into elements, compounds and mixtures :

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

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

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

What is a mixture ? Give two example of mixtures.

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

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

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

Which of the following is not an element ?

Which of  the following are compounds ?

1. CO
2. No
3. NO
4. Co

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

Which of the following is not a mixture ?

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

“Is malleable and ductile” best describes :

Which one of the following is not a metalloid ?

The elements which normally exist in the liquid state are :

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

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

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

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

Which of the following are homogeneous in nature ?

1. ice
2. wood
3. soil
4. air

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

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

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

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.

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.

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 ?

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 ?

Out of a colloid, solution and a suspension :

which one has the smallest particles ?

Out of a colloid, solution and a suspension :

which one has the largest particles ?

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

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

State whether colloidal solutions are homogeneous or heterogeneous.

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

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

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

Choose the correct answer.

A 5 per cent sugar solution means that :

Choose the correct answer.

A 15% alcohol solution means :

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

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

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

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

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

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

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

State whether the following statement is true or false :

Bread is an example of solid foam.

State whether the following statement is true or false :

Sponge is an example of solid sol.

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

aerosol, emulsion, colloid, sol

Which of the following is a sol ?

Shaving cream, Milk, Fog, Soap solution, Hairspray

Fill in the following blank :

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

Fill in the following blank :

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

Define solute.

Define solvent.

What is the difference between solutions and colloids ?

What is the difference between colloids and suspensions ?

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

Classify the following into true solutions and colloidal solutions:

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

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

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

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

How will you differentiate between a suspension and a colloid ?

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

Which of the following will show Tyndall effect ? Why ?

1. Salt solution
2. Starch solution
3. Milk
4. Copper sulphate solution

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

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.

Define Sol and give one example.

Define Aerosol Give one example.

Define the Emulsion Give one example.

Define Foam Give one example.

What is meant by the concentration of a solution ?

What will happen if a saturated solution is :

1. heated
2. cooled

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.

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

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

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

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

Freezing of water

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

 Rusting of iron

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

Glowing of an electric bulb

Classify the following as physical or chemical change :

Formation of curd from milk

Classify the following as physical or chemical change :

Condensation of steam

Classify the following as physical or chemical change :

Growth of a plant

Classify the following as physical or chemical changes :

Breaking of a glass tumbler

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

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.

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

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.

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

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

Give the main differences between physical changes and chemical changes.

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

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

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

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

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

What is a suspension ? Give two examples of suspensions.

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

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

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 ?

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

Which of the following is not an emulsion ?

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

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

Milk of Magnesia is :

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

Which one of the following is not a chemical change ?

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

Which of the following can be called a suspension ?

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

The rusting of an iron object is called :

A mixture of sulphur and carbon disulphide is :

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

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

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

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 ?

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.

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.

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 ?

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

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

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

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

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

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

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

Salt and Camphor

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

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

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

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

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

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

State whether the following statement are true or false :

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

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.

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

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

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

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

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

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

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

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

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

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

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

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

Name the process by which common salt is purified.

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

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

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

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

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

Fill in the following blanks with suitable words :

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

Fill in the following blanks with suitable words :

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

Fill in the following blanks with suitable words :

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

Fill in the following blanks with suitable words :

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

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..............

Fill in the following blanks with suitable words :

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

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 .......................

How will you separate a mixture containing sand and sugar ?

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

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

How would you separate a mixture of sugar and salt?

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

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

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

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

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

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

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

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

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

How will you separate iron pins from sand ?

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

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

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

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

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

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

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

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

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

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

How will you separate water from mustard oil ?

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

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

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

How is cream separated from milk ?

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

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

What is chromatography ? State its two applications.

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.

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.

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).

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 ?

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

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

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

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

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

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

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

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

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

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

Naphthalene can be separated from sand :

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

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

The boiling point of liquid argon is :

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 ?

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

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

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

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 ?

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.

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 ?

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 ?

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 ?