WBBSE Solutions For Class 9 Physical Science Chapter 4 Matter Separation Of The Components Of Mixture

Chapter 4 Matter Separation Of The Components Of Mixture Topic A Necessity Of Separation Of The Components Of A Mixture And Purification Of Petroleum Synopsis

1. A homogeneous mixture is one in which the mixture has the same proportion of the components throughout and has uniform properties at all parts of the mixture.
2. To separate useful substances from a mixture or to eliminate unwanted or harmful substances from a mixture, the components of a mixture need to be separated. Different methods applied for separation of mixtures are—crystallisation, distillation, fractional distillation, sublimation, filtration, chromatography etc.
3. Crude petroleum is a liquid mixture of hydrocarbons containing 1-40 carbon atoms (C₁– C₄₀). Considering its immense importance in our everyday life, petroleum is often referred to as ‘liquid gold’. Crude petroleum is refined by the process of fractional distillation.

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The Four Main Parts Obtained From Fractional Distillation Of Petroleum Are:-

1. Crude naphtha,
2. Kerosene or paraffin oil,
3. Fuel oil or diesel,
4. Residual oil.

Chapter 4 Matter Separation Of The Components Of Mixture Topic A Necessity Of Separation Of The Components Of A Mixture And Purification Of Petroleum Short And Long Answer Type Questions

Question 1. Define mixture. Classify the mixture into different types.

Answer:

Mixture:-

A mixture is the physical combination of two or more substances combined in any possible proportion by mass, in which the identities of the components are retained.

Mixtures may be classified in two types

1. Homogeneous mixture and
2. Heterogeneous mixtures.

Question 2. What is a homogeneous mixture? Give example.

Answer:

Homogeneous Mixture:-

1. A homogeneous mixture is one in which the components of the mixture has the same proportion throughout and has uniform properties at all parts of the mixture.
2. Aqueous solution of sugar, aqueous solution of alcohol etc. are homogeneous mixtures.

Question 3. Define heterogeneous mixtures.

Answer:

Heterogeneous Mixtures:-

A heterogeneous mixture is a mixture with a non uniform composition. The composition varies from one region to another with at least two phases that remain separate from each other, with clearly identifiable properties.

Example: mixture of sand and water, mixture of chalk-dust and water. Concrete is a heterogeneous mixture of cement and water.

Question 4. Write the differences between homogeneous mixtures and compounds.

Answer:

Differences Between Homogeneous Mixtures And Compounds:-

The major differences between homogeneous mixtures and compounds are as follows

Question 5. Why is it necessary to separate the components of a mixture?

Answer:

It Is Necessary To Separate The Components Of A Mixture Because:-

1. Separation methods are necessary for the removal of unwanted and harmful components from a mixture. For example, removal of impurities like soil particles, dirt etc. from water makes it suitable for drinking.
2. Useful components can be obtained from a mixture by applying different separation techniques. For example, petrol, diesel, kerosene, etc. are obtained from crude petroleum by fractional distillation.

Question 6. What is petroleum? in which process its components can be separated?

Answer:

Petroleum:-

1. Petroleum is a naturally occurring sticky liquid with characteristic smell, found beneath the earth’s surface and is a mixture of hydrocarbons containing 1 to 40 number of carbon atoms.
2. In petroleum, a mixture of hydrocarbons with boiling points in the range of 20°C-400°C are present. That is why to separate different components of it, fractional distillation is used.

Question 7. Why is it necessary to separate the components of petroleum?

Answer:

Yes It is Necessary To Separate The Components Of Petroleum:-

Petroleum is a mixture of different hydrocarbons containing 1 to 40 carbon atoms. It is the major source of different fuels like petrol, diesel, kerosene and a number of useful chemicals like lubricating oil, bitumen, paraffin wax etc.

These substances are widely used in different household activities as well as in industries. Thus, refining of crude petroleum i.e., separation of the components of petroleum is necessary.

Question 8. Show how the gaseous components of air are separated with the help of a flowchart.

Answer:

Question 9. Mention name and uses of different substances that can be obtained from petroleum.

Answer:

Different substances obtained at different temperature in the process of fractional distillation of crude petroleum are mentioned below

Chapter 4 Matter Separation Of The Components Of Mixture Topic A Necessity Of Separation Of The Components Of A Mixture And Purification Of Petroleum Very Short Answer Type Questions Choose The Correct Answer

Question 1. During fractional distillation of crude petroleum into its constituents, petrol distils at

1. 70°C
2. 120°C
3. 250°C
4. 400°C

Answer: 1. 70°C

Question 2. The correct order of density of

(1)Ether,

(2)Petrol and

(3) Kerosene is

1. (1) < (3) < (2)
2. (1) < (2) > (3)
3. (3) > (2) > (1)
4. (1) > (2) > (3)

Answer: 3. (3) > (2) > (1)

Question 3. Which of the following is a homogeneous mixture?

1. Water and oil
2. Water and alcohol
3. Water and sand
4. Water and benzene

Answer: 2. Water and alcohol

Question 4. The component of crude petroleum which gets distilled at the lowest temperature is

1. Bitumen
2. Refinery gas
3. Naphtha
4. Kerosene

Answer: 2. Kerosene

Question 5. The component of crude petroleum which gets distilled at the highest temperature is

1. Bitumen
2. Diesel
3. Gasoline
4. Kerosene

Answer: 1. Bitumen

Question 6. Which of the following is not obtained due to fractional distillation of petroleum?

1. Kerosene
2. Naphtha
3. Bitumen
4. Coal gas

Answer: 4. Coal gas

Question 7. The component of petroleum which is not used as a fuel is

1. Petrol
2. Naphtha
3. Kerosene
4. Diesel

Answer: 2. Naphtha

Question 8. The temperature at which LPG is obtained during fractional distillation of petroleum is

1. Below 30°C
2. Above 30°C
3. Above 50°C
4. 95°-100°C

Answer: 1. Below 30°C

Question 9. Which of the following is obtained from the fractional distillation of petroleum

1. Polythene
2. Ammonia
3. Diesel
4. Teflon

Answer: 3. Diesel

Question 10. Diesel is obtained by fractional distillation of petroleum at

1. 70°C
2. 170°C
3. 270°C
4. 370°C

Answer: 3. 270°C

Question 11. Which one of the following is not a homogeneous mixture?

1. Mixture of water and common salt
2. Mixture of sugar and water
3. Mixture of water and alcohol
4. Blood

Answer: 4. Mixture of water and alcohol

Question 12. Which one of the following is not a heterogeneous mixture?

1. Blood
2. Milk
3. Muddy water
4. Air

Answer: 4. Air

Chapter 4 Matter Separation Of The Components Of Mixture Topic A Necessity Of Separation Of The Components Of A Mixture And Purification Of Petroleum Answer In Brief

Question 1. Between compounds and mixtures, the components of which one can be separated by simple physical processes?

Answer: The components of a mixture can be separated by simple physical processes.

Question 2. Give an example of a homogeneous mixture.

Answer:

Example of a homogeneous mixture

An aqueous solution of sugar.

Question 3. A mixture consists of nearly ground wheat flour and sugar. Different parts of the mixture are tasted but the sweetness of the mixture is not uniform throughout the mixture. What may be the reason?

Answer: The sweetness of the mixture is not uniform throughout the mixture because it is a heterogeneous mixture.

Question 4. Which process is used in the refining of crude petroleum?

Answer: Fractional distillation.

Question 5. Is it possible to separate the constituents of petroleum by distillation?

Answer: No, it is not possible to separate the constituents of petroleum by distillation.

Question 6. What is the basis of separation of the components of crude petroleum? Or, By which physical property the components of petroleum can be differentiated?

Answer: The different components of crude petroleum are separated on the basis of their difference in boiling points by fractional distillation method.

Question 7. Name a solid substance obtained from the fractional distillation of petroleum.

Answer: Paraffin.

Question 8. What is petroleum gas?

Answer:

Petroleum gas

The hydrocarbon filtrate part containing 1 to 4 carbon atoms, obtained by fractional distillation of petroleum at 20°C to 30°C is termed as petroleum gas.

Question 9. What is the main component of petroleum gas?

Answer:

Main component of petroleum gas

Butane.

Question 10. What is asphalt?

Answer:

Asphalt

The black, sticky residue obtained from fractional distillation of petroleum is termed as asphalt.

Question 11. How is gasoline generally known to us?

Answer: Gasoline is known as petrol.

Question 12. Arrange in ascending order of boiling point—petrol, diesel, lubricating oil and kerosene.

Answer: Petrol < kerosene < diesel < lubricating oil.

Question 13. Name some liquid fuels obtained from petroleum by fractional distillation.

Answer: Petrol or gasoline, diesel and kerosene.

Question 14. What is obtained at lowest temperature in the refinement of petroleum?

Answer: Petroleum gas is obtained at lowest (20°C) temperature.

Chapter 4 Matter Separation Of The Components Of Mixture Topic A Necessity Of Separation Of The Components Of A Mixture And Purification Of Petroleum Fill In The Blanks

Question 1. The component of petroleum which is used in construction of roads is ________

Answer: Asphalt

Question 2. The other name of petrol is ________

Answer: Gasoline

Question 3. The main component of petroleum gas is _________

Answer: Butane

Question 4. ________ gas is used as household fuel for cooking.

Answer: Petroleum

Question 5. Petroleum is purified by

Answer: Fractional distillation

Chapter 4 Matter Separation Of The Components Of Mixture Topic A Necessity Of Separation Of The Components Of A Mixture And Purification Of Petroleum State Whether True Or False

Question 1. Naphtha obtained from fractional distillation of petroleum is used as a fuel.

Answer: False

Question 2. Bitumen is obtained as residue in the fractional distillation of petroleum.

Answer: True

Question 3. Milk of magnesia is an example of homogeneous mixture.

Answer: False

Question 4. Coal tar is obtained by the destructive distillation of bituminous coal.

Answer: True

Question 5. Crude petroleum oil can be used as fuel.

Answer: False

Question 6. Petroleum consists of more than 150 types of hydrocarbons.

Answer: True

Question 7. Kerosene is used as a solvent of DDT.

Answer: True

Chapter 4 Matter Separation Of The Components Of Mixture Topic B Distillation Fractional Distillation Separatory Funnel Synopsis

1. The boiling point of a liquid increases when pressure above the surface of the liquid increases, i.e., the liquid boils at a higher temperature compared to its normal boiling point.
2. The process of distillation is applied to separate the components of a mixture consisting of a non-volatile solid dissolved in a liquid. It is used mainly to separate the liquid component. For example, iodine and chloroform can be separated from their mixture by distillation. This process is extensively used in the purification of substances by solvent extraction method.
3. The components of a homogeneous mixture consisting of two liquids can be separated by simple distillation if (1)The difference in boiling points of the two liquids is greater than 30°C and (2) The liquids do not decompose or react with each other on heating. Thus, separation of benzene (boiling point =80°C) and aniline (boiling point = 184°C) from their mixture may be done by simple distillation.
4. When a mixture of two liquids with different boiling points is heated at a constant pressure, the relative proportion of the more volatile component is greater in the formed vapour than the relative proportion of that component present in the liquid mixture. If the difference in boiling points of the liquids is more than 30°C, the vapour phase mostly contains the more volatile component (i.e. liquid with the lower boiling point) when the liquid mixture is heated around the boiling point of the more volatile component.
5. The liquids separated by simple distillation are not pure. On heating, the more volatile component gets preferentially vapourised. However, it also contains a small fraction of the less volatile component which gets condensed and mixed with the more volatile liquid.
6. The components of a homogeneous mixture of two or more miscible liquids can conveniently be separated by fractional distillation if the difference in their boiling points is less than 10°C. For example, acetone (boiling point =56°C) and methanol (boiling point =65°C) are separated from their mixture by the process of fractional distillation.
7. In fractional distillation, the vapour produced on heating the liquid mixture will contain the more volatile component in greater amount than the other components. The liquid with the lowest boiling point distils first and the liquid with the highest boiling point distils at the end. This process is very useful for separation of benzene from coal tar; oxygen, nitrogen and other gases from liquid air and also in refining of crude petroleum.
8. During fractional distillation, the relative proportion of the more volatile component in the vapour produced by heating the liquid mixture, increases as it moves up along the fractionating column. The condensed part of the vapour that comes down as liquid in the column, contains mostly the less volatile component.
9. A mixture of liquids which boils with constant composition at a given temperature and pressure is known as an azeotropic mixture. It is possesses the same composition of components in both liquid phase and vapour phase. A mixture of 95.6% ethyl alcohol and 4.4% water is an example of azeotropic mixture. On heating, the entire mixture changes into the vapour phase at constant temperature. As a result, components of an azeotropic mixture cannot be separated by fractional distillation.
10. A separatory funnel is used to separate the components of a mixture consisting of two or more immiscible liquids having different densities. This funnel is useful in the separation of kerosene and water, water and mercury, chloroform and water from their mixtures.

Chapter 4 Matter Separation Of The Components Of Mixture Topic B Distillation Fractional Distillation Separatory Funnel Short And Long Answer Type Questions

Question 1. What is distillation?

Answer:

Distillation:-

The process by which a mixture consisting of a liquid and dissolved solid substances is vaporised by applying heat, followed by condensing the vapour back into the liquid state, thereby separating the components of the mixture is called distillation.

Question 2. What is the working principle of distillation?

Answer:

The Working Principle Of Distillation:-

The process of distillation is quite useful for separating the components of a mixture consisting of two miscible liquids, the difference in their boiling points being greater than 30°C. This process is also effective in separating the components from a mixture consisting of a liquid and non-volatile solid impurities.

When the solution is heated around the boiling point of the more volatile component, the vapour phase formed contains the more volatile component in a relatively higher proportion. The vapour is then condensed to the corresponding liquid and collected in a beaker.

When the temperature is raised to the boiling point of the less volatile component, the vapour phase formed contains the less volatile component in relatively higher proportion because the more volatile component has almost completely distilled off at a lower temperature.

Thus in distillation, the liquids distill off from the mixture at their respective boiling points as vapours and the vapours are then condensed to liquid phase and collected in beakers. The most volatile component distills off first while the least volatile component distills off at the end.

Question 3. Which type of mixtures are separated by distillation?

Answer:

Types Of Mixtures Are Separated By Distillation Are Given Below:-

Distillation is used to separate a homogeneous mixture of a solid dissolved in a liquid and to separate the components of a mixture consisting of two miscible liquids if the difference in boiling points of the liquids is in the range of 30-50°C and the liquids do not decompose on heating.

Question 4. What is Liebig condenser?

Answer:

Liebig condenser

The Liebig condenser or straight condenser is a piece of laboratory equipment, consisting of a straight glass tube surrounded by a water jacket in which water is constantly circulated to carry away the heat of vaporisation released by the condensing vapour.

Question 5. Give an example of a natural distillation process.

Answer:

Example of a natural distillation process

Sea water evaporates leaving behind the salts in the sea. Water vapours obtained as a result of such evaporation go upward and form clouds. From these clouds when water comes down to earth as rain, it does not contain any salt in it. Therefore the water cycle may be cited as an example of natural distillation process.

Question 6. What is vaccum distillation? When this process is applied?

Answer:

Vaccum distillation

Vacuum distillation is distillation performed under reduced pressure, which allows the purification of compounds not readily distilled at ambient pressures or simply to save time or energy. This process allows the components to be distilled at a lower temperature than their boiling points.

Vacuum distillation is ideal for separating mixture of liquids with very high boiling points. The lowering of pressure enables the components to boil at lower temperature.

Once the vapour pressure of the component is equal to the surrounding pressure, it is converted to vapour, which are then condensed and collected as distillate. The vacuum distillation is also used to obtain high-purity samples of compounds that decompose at high temperatures.

Question 7. What is fractional distillation?

Answer:

Fractional distillation

The process of separation of a mixture consisting of two miscible liquids having a difference of boiling point less than 25°C, by repeated condensation and vapourisation in a fractionating column is known as fractional distillation.

Question 8. Write down the basic principle of fractional distillation.

Answer:

The basic principle of fractional distillation

Fractional distillation is used to separate a mixture of two or more miscible liquids which boil without decomposition and for which the difference in boiling points is less than 25°C.

If a mixture of such kind is heated, the liquid with the least boiling point evaporates first and its vapour s transformed to pure liquid by condensation. By increasing the temperature slowly, other components of the mixture are obtained in their pure form.

Question 9. Under which conditions, fractional distillation is used instead of simple distillation?

Answer:

Simple distillation method is not suitable for separation of components of a mixture containing two or more miscible liquids having a difference in boiling point less than 25°C. The more volatile component vapourises when the mixture is heated near its boiling point.

However, as the difference in boiling point is small, other less volatile components also vapourise in small amounts and deposit in the receiving flask. Thus, complete separation of the components of the mixture does not take place by simple distillation. So, fractional distillation is done in which the mixture by repeated vaporisation and condensation in the fractionating column separates into its components.

Question 10. State important applications of fractional distillation.

Answer:

Important applications of fractional distillation

1. Crude petroleum is refined by fractional distillation to get different components like petrol, diesel, kerosene, lubricating oil etc.
2. Different gaseous components (oxygen, nitrogen etc.) are separated from liquid air by the process of fractional distillation.
3. Benzene is separated from coal tar, using fractional distillation.
4. From a mixture of acetone and methyl alcohol components are separated using fractional distillation.

Question 11. How will you separate benzene (bp 80°C) and toluene (bp 110°C) form a mixture?

Answer:

Benzene and toluene can be separated from their mixture by fractional distillation.The mixture should be taken in a distillation flask and thermometer, fractionating column, condenser etc. should be attached as per standard procedure. The flask should be hosted in an oil bath. AT 80°C boiling starts and the temperature remains constant.

At this temperature benzene vapour passes through the fractionating column and the condenser, condensed to liquid form and collected. After complete distillation of benzene, temperature of the mixture starts to increase. At 110°C toluene starts to vapourise and after passing through the fractionating column and the condenser, collected as liquid toluene.

Question 12. What are the limitations of fractional distillation?

Answer:

Limitations of fractional distillation

The process of fractional distillation cannot be used to separate the components of an azeotropic mixture (constant boiling mixture). For example, a mixture of 95.6% ethyl alcohol and 4.4% water cannot be separated by fractional distillation because it forms a constant boiling mixture or azeotropic mixture which boils at a constant temperature of 78.4°C.

Question 13. What is azeotropic mixture?

Answer:

Azeotropic mixture

Azeotropic mixture is the mixture of miscible liquids that has a constant boiling point because the vapour has the same composition as the liquid mixture. The boiling point of an azeotropic mixture may be higher or lower than that of any of its components.

Question 14. Why a mixture of water and ethyl alcohol can not be separated completely by fractional distillation?

Answer:

While concentrating a mixture of ethanol and water through fractional distillation, a mixture of 95.6% ethanol and 4.40% water (by weight) is obtained at some point. On heating, at 78.4°C the whole liquid starts boiling and distilled in the same composition.

In fact, at that composition ethanol and water forms an azeotrope. That is why complete separation of ethanol or ethyl alcohol and water from their mixture can not be done through fractional distillation.

Question 15. How is the boiling point of a liquid related to the pressure above its surface? Write important applications of this property.

Answer:

1. The boiling point of a liquid increases if the pressure above its surface increases. Thus, the liquid boils at a higher temperature than its normal boiling point.

Application:

This property of liquid is applied in pressure cookers.

2. The boiling point of a liquid decreases if the pressure above its surface decreases. Thus, the liquid boils at a lower temperature than its normal boiling point.

Application:

Condensed milk is prepared by using this property. Milk is condensed by boiling it at a low temperature by decreasing the pressure.

Question 16. Write down the effect of boiling point of liquids.

Answer:

The effect of boiling point of liquids

Boiling point of liquids depend on the pressure exerted on the liquid. As the pressure increases, boiling point of liquids also increases and decreases with decrease in pressure.

Question 17. The components of which type of mixtures can be separated by using separatory funnel?

Answer:

A mixture of two immiscible liquids having appreciable difference in their densities can be separated by using a separatory funnel. Due to difference in the densities of the constituent liquids, if the mixture is kept undisturbed for some time, it forms two distinct layers. This property is used to separate the components of the liquid mixture by using a separatory funnel.

Question 18. Give two examples where separatory funnel is used to separate the components of a mixture.

Answer:

1. Separatory funnel is used to separate the components of a mixture of two immiscible liquids like oil and water, benzene and water, chloroform and water etc.
2. Separatory funnel is used to extract an organic compound dissolved in water by solvent extraction process.

Question 19. How water and carbon tetrachloride are separated from their mixture?

Answer:

The mixture of water and carbon tetrachloride is poured and kept for sometime in a separatory funnel. Carbon tetrachloride forms the lower layer and water forms the upper layer in the separatory funnel. Carbon tetrachloride is collected first by opening the stopcock and then water is collected in a separate vessel.

Question 20. Is it possible to separate water and alcohol from their mixture with the help of a separatory funnel?

Answer:

Liquids which are completely miscible with each other and forms a homogeneous mixture cannot be separated from their mixture with the help of a separatory funnel. Water and alcohol completely mix with each other in all proportions to form a homogeneous mixture. So, separatory funnel cannot be used to separate water and alcohol from their mixture.

Question 21. Complete the following table.

Answer:

Completing the following table by filling up the blanks, we get

Question 22. Differentiate between distillation and fractional distillation.

Answer:

Difference between distillation and fractional distillation

Question 23. Write down differences between fractional distillation and separation through separatory funnel.

Answer:

The differences between fractional distillation and separation through separatory funnel are

Chapter 4 Matter Separation Of The Components Of Mixture Topic B Distillation Fractional Distillation Separatory Funnel Very Short Answer Type Questions Choose The Correct Answer

Question 1. Which of the following is not a compound?

1. Benzene
2. Water
3. Petroleum
4. Toluene

Answer: 3. Petroleum

Question 2. The process of distillation can be used to separate the

1. Constituents of a mixture of water and salt
2. Constituents of a mixture of water and oil
3. Constituents of a mixture of water and sand
4. Constituents of a mixture of sugar and salt

Answer: 1. Constituents of a mixture of water and salt

Question 3. Which of the following mixtures cannot be l separated into its constituents by using a separatory funnel?

1. Water and mercury
2. Petrol and water
3. Cchloroform and water
4. Ethanol and water

Answer: 4. Ethanol and water

Question 4. A fractionating column is used for the process of

1. Filtration
2. Distillation
3. Vapourisation
4. Fractional distillation

Answer: 4. Fractional distillation

Question 5. enzene and toluene can be separated from their mixture by

1. Filtration
2. Distillation
3. Fractional distillation
4. Using separatory funnel

Answer: 3. Fractional distillation

Question 6. Which of the following process of separation of a mixture does not require heating?

1. Distillation
2. Sublimation
3. Using separatory funnel
4. Fractional distillation

Answer: 3. Using separatory funnel

Question 7. Water can be boiled at room temperature by

1. Decreasing the pressure
2. Increasing the pressure
3. Initially increasing the pressure and then decreasing it
4. Initially decreasing the pressure and then increasing it

Answer: 1. Decreasing the pressure

Question 8. During fractional distillation of two miscible liquids, the distilled vapour produced on heating the mixture is rich in

1. Less volatile liquid
2. More volatile liquid
3. Both the liquids
4. None of the liquids

Answer: 2. More volatile liquid

Question 9. Which of the following is required in solvent extraction method?

1. Filter paper
2. Funnel
3. Separatory funnel
4. Beaker

Answer: 3. Separatory funnel

Question 10. Benzene and nitrobenzene can be separated from their mixture by

1. Fractional distillation
2. Filtration
3. Simple distillation
4. Sublimation

Answer: 3. Simple distillation

Question 11. The glass apparatus which is used to separate the components of a mixture consisting of two or more immiscible liquids is called

1. Fractionating column
2. Condenser
3. Separatory funnel
4. Buchner funnel

Answer: 3. Separatory funnel

Question 12. A salt can be extracted from its aqueous solution by

1. Sublimation
2. Filtration
3. Distillation
4. Fractional distillation

Answer: 3. Distillation

Question 13. For every 27 mm increase in atmospheric pressure, the boiling point of water increases by

1. 1°C
2. 2°C
3. 3°C
4. 4°C

Answer: 1. 1°C

Question 14. The boiling point of water at Darjeeling will be

1. More than 100°C
2. Less than 100°C
3. Equal to 100°C
4. Cannot be determined

Answer: 2. Less than 100°C

Question 15. The process of separation of components from the mixture of chloroform (boiling point 61°C) and benzene (boiling point 80°C) is

1. Distillation
2. Fractional distillation
3. Separating funnel
4. Filtration

Answer: 2. Fractional distillation

Question 16. From which of the following mixtures, components cannot be separated by fractional distillation?

1. Water + ethyl alcohol (bp: 78.2°C)
2. Water + kerosene (bp: 170°C)
3. Acetone (bp:56°C)+ methanol (bp: 65°C)
4. Water + benzene (bp: 80°C)

Answer: 1. Water + ethyl alcohol (bp: 78.2°C)

Question 17. The process by which the components of a mixture of ethanol and water can be separated is

1. Distillation
2. Fractional distillation
3. Sublimation
4. None of the above

Answer: 4. None of the above

Question 18. The process by which the components of a mixture of ammonium chloride and sand can be separated is

1. Distillation
2. Fractional distillation
3. Sublimation
4. Chromatography

Answer: 3. Sublimation

Question 19. The process used to separate the gaseous components of air is

1. Distillation
2. Fractional distillation
3. Sublimation
4. Separating funnel

Answer: 2. Fractional distillation

Question 20. Water can be boiled at 25°C if the standard atmospheric pressure is

1. Reduced
2. Increased
3. Increased at first and then reduced
4. Reduced at first and then increased

Answer: 1. Reduced

Question 21. The process of separation of a liquid and a non-volatile solid from their mixture is

1. Fractional distillation
2. Sublimation
3. Distillation
4. Crystallisation

Answer: 3. Distillation

Question 22. The process used to prepare salt from sea water is

1. Distillation
2. Evaporation
3. Fraction distillation
4. Filtration

Answer: 2. Evaporation

Question 23. Apparatus used in fractional distillation is

1. Condenser
2. Liebig’s condenser
3. Fractional column
4. 2 and 3 both

Answer: 4. 2 and 3 both

Question 24. Which one of the following cannot be obtained by the fractional distillation of crude petroleum?

1. Petrol
2. Diesel
3. Ethanol
4. Kerosene

Answer: 3. Ethanol

Question 25. How will you separate the components of a mixture of iodine and ethanol ?

1. Filtration
2. Evaporation
3. distillation
4. Fractional distillation

Answer: 3. distillation

Question 26. Distillation column is used in

1. Distillation
2. Fractional distillation
3. Condensation
4. Separatory funnel

Answer: 3. Condensation

Question 27. By which process water and carbon tetrachloride can be separated from their mixture?

1. Distillation
2. Fractional distillation
3. Evaporation
4. Separatory funnel

Answer: 4. Separatory funnel

Question 28. The components of a mixture of water and kerosene, can be separated by

1. Distillation
2. Fractional distillation
3. Separatory funnel
4. Sublimation

Answer: 3. Separatory funnel

Chapter 4 Matter Separation Of The Components Of Mixture Topic B Distillation Fractional Distillation Separatory Funnel Answer In Brief

Question 1. What are the processes of separation of component of a mixture of two liquids?

Answer: Distillation, fractional distillation, separating funnel etc.

Question 2. What change is observed in the boiling point of a liquid when the pressure above its surface is decreased?

Answer: When the pressure above the surface of a liquid is decreased, the liquid starts to boil at a lower temperature, i.e., the boiling point of the liquid decreases.

Question 3. What should be the minimum difference in the boiling points of two liquids if they are to be effectively separated by the process of distillation?

Answer: If the difference in the boiling points of two liquids is about 30-50°C, then they can be effectively separated by the process of distillation.

Question 4. Which constituent liquid will be in relatively higher amount in the vapour phase when a mixture containing two miscible liquids is heated during fractional distillation?

Answer: In fractional distillation of a mixture of two miscible liquids, the vapour phase will contain the more volatile liquid in relatively higher amount when the mixture is heated.

Question 5. How can a mixture of sand and iron dust be separated?

Answer: A mixture of sand and iron dust can be effectively separated by using a magnet. The process is called magnetic separation.

Question 6. Define sublimation.

Answer: Sublimation is the transition of a substance directly from the solid to the gaseous state, by the application of heat, without passing through the liquid state.

Question 7. In which process pure water can be obtained from an aqueous solution of salt?

Answer: By the process of distillation.

Question 8. By which process the components of a mixture of methanol (bp: 65°C) and water can be separated?

Answer: By the process of distillation.

Question 9. In which process the components of the mixture of ether (bp: 35°C) and benzene (bp: 80°C) can be separated?

Answer: Distillation.

Question 10. When is fractional distillation used for separating the components of a mixture?

Answer: If the difference in boiling points of two miscible liquids is less than 25°C, then those liquids are separated from their mixture by fractional distillation.

Question 11. Which apparatus is effectively used in fractional distillation of a mixture containing two or more miscible liquids, the difference in their boiling points being less than 25°C?

Answer: The apparatus which is effectively used in fractional distillation of a mixture containing two or more miscible liquids (the difference in their boiling points being less than 25°C), is a fractional distillation column or fractionating column.

Question 12. Which process is suitable to separate acetone and methanol from their mixture?

Answer: Acetone (boiling point = 56°C) and methanol (boiling point = 65°C) can be separated from their mixture by the process of fractional distillation.

Question 13. Is it possible to separate the components of a mixture containing two or more miscible liquids by distillation if the difference in their boiling points is 25°C?

Answer: No, it is not possible.

Question 14. Mention the percent amount of ethyl alcohol in rectified spirit which is an azeotropic mixture.

Answer: Rectified spirit which in an azeotropic mixture contains 95.6% ethyl alcohol.

Question 15. What is the boiling point of rectified spirit which is an azeotropic mixture?

Answer: The boiling point of rectified spirit which is an azeotropic mixture is 78.4°C.

Question 16. Two immiscible liquids, water and kerosene are kept in a beaker for some time. Which liquid will form the lower layer?

Answer: As water is heavier than kerosene, it will form the lower layer.

Question 17. Which process is suitable to separate water and kerosene from their mixture?

Answer: Water and kerosene can be separated from their mixture by using a separatory funnel.

Question 18. Is it possible to separate water and sand from their mixture by using a separatory funnel?

Answer: Water and sand cannot be separated from their mixture by using a separatory funnel.

Question 19. State whether fractional distillation is a physical or chemical process.

Answer: Fractional distillation is a physical process of separation of two or more miscible liquids.

Question 20. Which one of methanol and acetone will distill first if their mixture is being heated in a distillation flask?

Answer: Boiling points of methanol and acetone are 78.5°C and 56°C respectively. So acetone will distill first if their mixture is being heated in a distillation flask.

Question 21. Why the components of a mixture of methanol and acetone can not be separated by simple distillation?

Answer: The difference in boiling point of methanol (bp: 65°C) and acetone (bp: 56°C) is too small (9°C) to separate them by simple distillation. To separate the components from a mixture by simple distillation, difference in boiling point should be at least 30°C.

Question 22. Give example of azeotropic mixture.

Answer: The mixture of 95.6% ethanol and 4.4% water, is an example of azeotropic mixture.

Question 23. Name the suitable separation technique by which a mixture of two liquids of different boiling points can be separated.

Answer: Distillation or fractional distillation depending upon the difference in boiling points of the component liquids.

Question 24. By which process water and benzene can be separated from their mixture?

Answer: Using separatory funnel.

Question 25. Write down two essential conditions for separation of liquid mixture through separatory funnel?

Answer:

1. Density of the liquids should be different.
2. The liquids should be immisscible.

Question 26. How will you separate the components of a mixture containing water and kerosene or water and petrol?

Answer: By using separatory funnel.

Question 27. Name the separation technique by which the mixture of two immissible liquids can be separated.

Answer: By using separatory funnel.

Question 28. Name a liquid mixture the components of which can not be separated by separatory funnel.

Answer: A mixture of water and ethyl alcohol.

Chapter 4 Matter Separation Of The Components Of Mixture Topic B Distillation Fractional Distillation Separatory Funnel Fill In The Blanks

Question 1. A liquid starts to boil when the vapour pressure of the liquid is equal to the ________ pressure.

Answer: Atmospheric

Question 2. Two miscible liquids can be separated from their mixture by distillation if they do not ________ on heating.

Answer: Decompose

Question 3. During separation of a mixture consisting of two or more miscible liquids by fractional distillation, the liquid with the ________ boiling point will distill out first.

Answer: Lowest

Question 4. The different gaseous constituents of air is separated by ________

Answer: Fractional distillation

Question 5. Water can be boiled at room temperature (25°C) if the pressure on water is ________ than the atmospheric pressure.

Answer: Less

Question 6. Ether and toluene can be separated from their mixture by _________

Answer: Distillation

Question 7. The process which is widely used in purification of substances by solvent extraction method is ________

Answer: Distillation

Question 8. Sugar is separated from its aqueous solution _______ by process.

Answer: Distillation

Question 9. Liquids that do not vapourise easily are called _________ liquids.

Answer: Non-volatile

Question 10. In an azeotropic mixture of rectified spirit, the percentage of water is _________

Answer: 4.4%

Question 11. In a fractionating column, as the vapour moves up in the column, the relative amount of the ________ volatile component in the vapour increases.

Answer: More

Question 12. In a fractionating column, the process of condensation and vapourisation take place _______ throughout the column.

Answer: Repeatedly

Question 13. Water and alcohol _______ be separated completely from their mixture by fractional distillation method.

Answer: Cannot

Question 14. The gaseous components of ______ air are separated by fractional distillation.

Answer: Liquid

Question 15. A mixture of water and mustard oil can be separated by using ______

Answer: Separatory funnel

Question 16. Benzene is extracted from coal tar by the process of ________

Answer: Fractional distillation

Question 17. Two liquids cannot be seperated by fractional distillation if their mixture forms an ________

Answer: Azeotrope

Question 18. To cool down the vapours of the distilled liquid in distillation, _________ condenser is used.

Answer: Liebig

Question 19. Distillation = Evaporation + ________

Answer: Condensation

Question 20. In a mixture of water and chloroform, _______ forms the lower layer.

Answer: Chloroform

Question 21. Of the two liquids, the one with _______ density separates first by the separatory funnel.

Answer: More

Question 22. Separate ________ will be formed if a mixture of water and oil is kept for sometime in a separatory funnel.

Answer: Layer

Question 23. Two _______ liquids can be separated from their mixture using separatory funnel.

Answer: Immiscible

Chapter 4 Matter Separation Of The Components Of Mixture Topic B Distillation Fractional Distillation Separatory Funnel State Whether True Or False

Question 1. If the difference in the boiling points of two liquids is 30°C, then those liquids can be separated from their mixture by the process of simple distillation.

Answer: True

Question 2. Fractional distillation is a chemical process of separation of mixtures.

Answer: False

Question 3. A mixture of water and benzene forms a homogeneous mixture.

Answer: False

Question 4. Two immiscible liquids of different densities can be separated from their mixture by a separatory funnel.

Answer: True

Question 5. The different components of liquid air are separated by the process of fractional distillation.

Answer: True

Question 6. Boiling point of a liquid decreases if pressure above the liquid is increased.

Answer: False

Question 7. A mixture of sand and iron dust is separated by magnetic separation.

Answer: True

Question 8. It is not possible to boil water at room temperature.

Answer: False

Question 9. Azeotropic mixtures cannot be separated by fractional distillation.

Answer: True

Question 10.During fractional distillation of two miscible liquids, the less volatile component remains in the vapour phase in greater proportion.

Answer: True

Question 11. Water forms the upper layer when it is kept with kerosene in a beaker.

Answer: False

Question 12. During the process of distillation, the most volatile component distils out last while the least volatile component distils out first.

Answer: False

Question 13. A mixture of water and alcohol can be separated by using a separatory funnel.

Answer: False

Question 14. Fractional distillation is used to separate salt from sea water.

Answer: False

Question 15. Boiling point of methanol is greater than that of water.

Answer: False

Question 16. Boiling point of liquid decreases by decreasing pressure.

Answer: True

Question 17. In a mixture of carbon disulphide and water, carbon disulphide constitutes the lower layer.

Answer: True

Question 18. The mixture of acetone and water can be separated using separatory funnel.

Answer: False

Question 19. Colloid solutions can be separated by separatory funnel.

Answer: False

Chapter 4 Matter Separation Of The Components Of Mixture Topic B Distillation Fractional Distillation Separatory Funnel Miscellaneous Type Questions

Match The Column

1.

Answer: 1. B, 2. D, 3. A, 4. C

2.

Answer: 1. C, 2. A, 3. D, 4. B