Chapter 4.5 – Separation of Component of Mixture | Chapter Solution Class 9

Multiple Choice Questions (MCQ)

[Each of Mark-1]

Question 1

A solution of sugar in water is

1. a homogeneous mixture
2. a heterogeneous mixture
3. separated two immiscible liquids
4. none of these

Answer

a homogeneous mixture

Explanation

A solution of sugar in water is a homogeneous mixture because the sugar molecules are uniformly distributed throughout the water.

Question 2

Bronze is an example of

1. solid in a solid homogeneous mixture
2. solid is a solid heterogeneous mixture
3. solid is a liquid homogeneous mixture
4. solid in a liquid heterogeneous mixture

Answer

solid in a solid homogeneous mixture

Explanation

Bronze is an example of a solid in a solid homogeneous mixture, as it is an alloy composed of copper and tin uniformly mixed at the atomic level.

Question 3

Which one is solid in the liquid homogeneous mixture?

1. gun powder
2. water in sponge
3. lodine in alcohol
4. oil in water

Answer

Iodine in alcohol

Explanation

Iodine in alcohol is an example of a solid in a liquid homogeneous mixture, as the iodine particles are uniformly dispersed in the alcohol solvent.

Question 4

A mixture of common salt (NaCl) and NH4Cl(s) can be separated by

1. magnetic separation
2. mechanical picking
3. sublimation
4. filtration

Answer

sublimation

Explanation

The mixture of common salt (NaCl) and NH₄Cl(s) can be separated by sublimation since NH₄Cl sublimes directly from solid to gas leaving NaCl behind.

Question 5

Sedimentation and decantation in a method of separation suitable for

1. solid in a solid homogeneous mixture
2. liquid in a liquid homogeneous mixture
3. solid in a liquid heterogeneous mixture
4. solid in a solid heterogeneous mixture

Answer

solid in a liquid heterogeneous mixture

Explanation

Sedimentation and decantation are methods of separation suitable for separating solid in a liquid heterogeneous mixture. In this process, the solid particles settle down (sedimentation) and the clear liquid is poured off (decantation).

Question 6

Fractional distillation is used for the separation of a mixture

1. solid in the liquid mixture
2. liquid in solid
3. liquid-liquid immiscible
4. liquid-liquid miscible

Answer

liquid-liquid miscible

Explanation

Fractional distillation is used for the separation of a liquid-liquid miscible mixture, where the components have different boiling points and can be vaporized and condensed at different temperatures.

Question 7

The use of a separatory funnel

1. depends on volume ratio of two liquids
2. depends on density difference of two liquids
3. does not depends on miscibility of liquids
4. depends on temperature

Answer

depends on the density difference of two liquids

Explanation

The use of a separatory funnel depends on the density difference of two liquids, as it allows for the separation based on the principle of liquid-liquid phase separation.

Question 8

The use of fractional distillation depends on

1. volume ratio of liquids
2. density ratio of liquids
3. difference in boiling points of the liquids
4. on colour of the liquids

Answer

the difference in boiling points of the liquids

Explanation

The use of fractional distillation depends on the difference in boiling points of the liquids being separated. It enables the separation based on their vaporization and condensation temperatures.

Question 9

Which one is not a product of the fractional distillation of crude petroleum?

1. petrol
2. diesel
3. ethanol
4. kerosene

Answer

Ethanol

Explanation

Ethanol is not a direct product of the fractional distillation of crude petroleum. It is typically produced through fermentation or other processes involving biomass or grains.

Question 10

Water boils at 100°C under the pressure of

1. 760 cm of Hg 
2. 76 cm of Hg
3. 7.6 mm of Hg
4. 7.6 cm of Hg

Answer

760 cm of Hg

Explanation

Water boils at 100°C under the pressure of 760 mm of Hg (mercury), which is equivalent to 760 cm of Hg.

Answer in one word or in one sentence

[Each of Mark-1]

Questions 1

What is a mixture?

Answer

A mixture is a combination of two or more substances that are physically combined but not chemically bonded together.

Questions 2

Which component is present in a higher percentage in brass ?

Answer

The component present in a higher percentage in brass is copper (typically ranging from 55% to 90% in composition).

Questions 3

Name an alloy of aluminium.

Answer

An alloy of aluminum is called “duralumin.”

Questions 4

What separation method would you suggest for separation between (i) kerosene and water, (ii) two liquids of different densities.

Answer

(i) separatory funnel.

(ii) fractional distillation.

Questions 5

Give an example of a gas in gas (i) heterogeneous, (ii) homogeneous mixture.

Answer

1. air is a homogeneous mixture
2. Water vapour (think clouds) is a heterogeneous mixture

Questions 6

What is sublimation ?

Answer

Sublimation is the process in which a substance transitions directly from a solid to a gas phase without passing through the liquid phase.

Questions 7

Give an example of using the method of sublimation.

Answer

An example of sublimation is when solid dry ice (frozen carbon dioxide) turns directly into gas without melting into a liquid.

Questions 8

What is (i) sedimentation, (ii) evaporation, (iii) boiling, (iv) filtration ?

Answer

1. Sedimentation: The process where solid particles settle down at the bottom of a liquid due to gravity.
2. Evaporation: The process of converting a liquid into a gas by heating or exposing it to heat.
3. Boiling: The process in which a liquid turns into a vapor state when heated to its boiling point.
4. Filtration: The method of separating solid particles from a liquid or gas by passing it through a porous material called a filter.

Questions 9

What is (i) alloy, (ii) distillate, (iii) filtrate, (iv) sediment.

Answer

1. Alloy: A mixture of two or more metals or metals with a non-metal, typically formed by melting and blending them together.
2. Distillate: The liquid collected or condensed during the process of distillation, where a liquid mixture is heated and the vapours are condensed back into liquid form.
3. Filtrate: The liquid that passes through a filter during the process of filtration, separating it from the solid particles.
4. Sediment: Solid particles that settle down at the bottom of a liquid due to gravity, forming a layer or deposit.

Questions 10

What is a separatory funnel ?

Answer

A separatory funnel is a laboratory tool used for separating immiscible liquids of different densities by allowing them to settle into distinct layers for easy separation.

Short answer type questions

[Each of Mark-2 or 3]

Questions 1

Name the physical process which is applied to separate acetone and ethyl alcohol. Why would you apply this method?

Answer

The physical process applied to separate acetone and ethyl alcohol is “fractional distillation.” This method is used because acetone and ethyl alcohol have different boiling points, allowing them to vaporize and condense at different temperatures for separation.

Questions 2

Name the process by which the components of crude oil may be separated. Name three such components. 

Answer

The process by which the components of crude oil may be separated is called “fractional distillation.” Three components that can be separated from crude oil are gasoline, diesel fuel, and kerosene.

Questions 3

Differentiate between ordinary distillation and fractional distillation processes.

Answer

1. Ordinary distillation is used when the components of a mixture have significantly different boiling points, while fractional distillation is used for mixtures with closer boiling points.
2. Fractional distillation uses a fractionating column to achieve better separation by providing multiple vaporization and condensation stages, while ordinary distillation does not employ such a column.
3. Fractional distillation allows for the separation of a mixture into more precise fractions, while ordinary distillation generally results in a less refined separation.

Questions 4

Give a sketch to represent fractional distillation. Mention one industrial use of this process.

Answer

One industrial use of fractional distillation is in the refining of crude oil to produce different petroleum products such as gasoline, diesel fuel, and jet fuel.

Questions 5

Explain the working principle for fractional distillation mentioning the importance of boiling points.

Answer

The working principle of fractional distillation relies on the fact that different components in a liquid mixture have different boiling points. Here’s how it works:

Fractional distillation works by heating a mixture of liquids to separate them based on their different boiling points. The liquid with the lowest boiling point evaporates first and rises in the distillation (Fractionating) column, while the one with the higher boiling point remains in liquid form. This separation happens because substances with different boiling points condense at different heights in the column, allowing for efficient separation based on boiling point differences.