Exercise II on Pure Substances and Mixtures; Separation of Mixtures Class 6 Concise Chemistry ICSE Solutions Ch-5. In this article you would learn how to solve Exercise II on Pure Substances and Mixtures; Separation of Mixtures with hint and reason. Visit official Website CISCE for detail information about ICSE Board Class-6.
Exercise II on Pure Substances and Mixtures; Separation of Mixtures Class 6 Concise Chemistry ICSE Solutions
| Board | ICSE |
| Publications | Selina Publication |
| Subject | Chemistry |
| Class | 6th |
| Chapter-5 | Pure Substances and Mixtures; Separation of Mixtures |
| Book Name | Concise |
| Topics | Solution of Exercise II |
| Academic Session | 2025-2026 |
Exercise II on Pure Substances and Mixtures; Separation of Mixtures
Objective Type Questions
Que-1: The process of adding a chemical substance to help the suspended solid particles to deposit as sediment faster is called:
(i) loading
(ii) sedimentation
(iii) decantation
(iv) filtration
Ans- loading
Reason — The process of helping fine solid particles in a solid-liquid mixture to settle faster, by adding a special chemical, is called loading or coagulation.
Que-2: Salt is separated from sea water by:
(i) evaporation
(ii) sublimation
(iii) magnetic separation
(iv) filtration
Ans- evaporation
Reason — Salt from sea water is separated by evaporation. Sea water is collected in shallow beds and allowed to evaporate in the sun. When all the water is evaporated, salt is left behind.
Que-3: A gas dissolved in a liquid can be separated by:
(i) filtration
(ii) boiling
(iii) using magnet
(iv) sublimation
Ans- boiling
Reason — A mixture of gas in liquid can be separated by heating or boiling. Dissolved gas escapes from the liquid on heating or boiling.
Que-4: Camphor can be separated from a mixture of sand and camphor by :
(i) filtration
(ii) evaporation
(iii) sublimation
(iv) winnowing
Ans-sublimation
Reason — Camphor can be separated from a mixture of sand and camphor by sublimation. The camphor sublimes and escapes as vapour, while the sand is left behind.
Que-5: A separating funnel is used to separate :
(i) miscible liquids
(ii) sugar solution
(iii) chalk powder and water
(iv) immiscible liquids
Ans- immiscible liquids
Reason — A separating funnel is a laboratory tool used to separate immiscible liquids. The denser liquid settles at the bottom, and the lighter one floats on top. When we open the stopcock the bottom layer drains first, effectively separating the two.
Fill in the blank
Que-1: The substances that make a mixture are called its .. ….. …. or .. …. ….. .
Ans- The substances that make a mixture are called its components or constituents.
Que-2: … ….. … is a process to separate solids dissolved in liquids.
Ans- Evaporation is a process to separate solids dissolved in liquids.
Que-3: Mist is a … …. …. mixture of droplets of water and air.
Ans- Mist is a heterogeneous mixture of droplets of water and air.
Que-4: Clay is separated from water by the method of …. …. … .
Ans- Clay is separated from water by the method of filtration.
Que-5: When cereals are washed before cooking, water is separated from the cereals by … …. …. .
Ans- When cereals are washed before cooking, water is separated from the cereals by decantation.
Que-6: … …. …. is a process to obtain a very pure form of a solid dissolved in a liquid.
Ans- Evaporation is a process to obtain a very pure form of a solid dissolved in a liquid.
Que-7: Ammonium chloride can be separated from common salt by the method of .. … …… .
Ans- Ammonium chloride can be separated from common salt by the method of sublimation.
Que-8: The solid particles which remain on the filter paper are called ….. … … and the liquid which passes through it is called …. …. …… .
Ans- The solid particles which remain on the filter paper are called residue and the liquid which passes through it is called filtrate.
Que-9: The process of transferring the clear liquid above the solid particles which settle at the bottom of the container is known as … …. …. .
Ans- The process of transferring the clear liquid above the solid particles which settle at the bottom of the container is known as decantation.
Que-10: .. ….. …. is a method used for the separation of an insoluble solid from a solid-liquid mixture.
Ans- Filtration is a method used for the separation of an insoluble solid from a solid-liquid mixture.
State True or False
Write “true” or “false” for the following statements:
Que-1: A pure substance consists of only one kind of atom or molecule. … .. ……
Ans- True
Que-2: The components of a mixture are present in a fixed ratio. .. ….. ….
Ans- False
Correct Statement — A mixture has no fixed composition, i.e. it is formed by mixing two or more substances in any ratio without any chemical reaction.
Que-3: Common salt is separated from its solution in water by decantation. …. … ….
Ans- False
Correct Statement — Common salt is separated from its solution in water by evaporation
Que-4: Winnowing is a process to remove small stones from grains. .. ….. ….
Ans- False
Correct Statement — Winnowing removes lighter husk from heavier grains, whereas, small stones are removed by hand picking or sieving.
Que-5: Gold jewellery is a homogeneous mixture of metals. … ….. …
Ans- True
Que-6: Air can be separated from water by filtration. … ….. …
Ans- False
Correct Statement — Air can be separated from water by heating or boiling.
Que-7: Salt and air dissolved in water add taste to water. ….. … …
Ans- True
Que-8: Steel is an alloy of iron and aluminium. … ….. …
Ans- False
Correct Statement— Steel is an alloy of iron and carbon.
Match the following:
Ans- (a) – (iii)
(b) – (iv)
(c) – (v)
(d) – (i)
(e) – (ii)
One Word Answer Type Questions
Give one word for the following:
Que-1: The solid which is left on the filter paper after filtration.
Ans- Residue
Que-2: The solid particles which separate out from the solution on slow evaporation.
Ans- Crystals
Que-3: The solid particles that settle at the bottom of the beaker in a heterogeneous mixture of a solid and a liquid.
Ans- Sediment
Que-4: The clear liquid which is poured out after sedimentation.
Ans- Supernatant liquid
Que-5: The technique used to separate the light particles from heavy particles using the flow of wind.
Ans- Winnowing
Name the process by which the components of the following mixtures can be separated.
Que-1: Powdered glass and sugar
Ans- Solvent extraction method and filtration
Que-2: Chalk powder and iron filings
Ans- Magnetic separation
Que-3: Chaff and grain
Ans- Winnowing
Que-4: Salt and water
Ans- Evaporation
Que-5: Wheat and sugar
Ans- Sieving
Que-6: Sand and camphor
Ans- Sublimation
Que-7: Sugar and water
Ans- Evaporation
Rearrange the Following
Rearrange the following to get meaningful words:
(all are methods to separate the components of mixtures).
Que-1: OIRATVOPEAN
Que-2: DNOITITLLIAS
Que-3: FTOLINTRAI
Que-4: SINIVEG
Ans- (1) EVAPORATION
(2) DISTILLATION
(3) FILTRATION
(4) SIEVING
Short Answer Questions
Que-1: Name:
(i) two substances which can sublime
(ii) two substances soluble in water
(iii) two substances insoluble in water
(iv) four substances that can be used as filters.
Ans- (i) Two substances which can sublime:
(a)Iodine
(b)Ammonium chloride
(ii) Two substances soluble in water:
(a)Sugar
(b)Common salt
(iii) Two substances insoluble in water:
(a)Sand
(b)Chalk powder
(iv) Four substances that can be used as filters:
(a)Filter paper
(b)Cotton wool
(c)Muslin cloth
(d)Fine sieve (wire gauze)
Que-2: Give one example for each of the following types of mixtures.
(i) Solid-solid heterogeneous mixture
(ii) Solid-liquid heterogeneous mixture
(iii) Solid-liquid homogeneous mixture
Ans- (i) Solid-solid heterogeneous mixture: Mixture of iron filings and sulphur
(ii) Solid-liquid heterogeneous mixture: Sand and water
(iii) Solid-liquid homogeneous mixture: Sugar solution (sugar dissolved in water) or salt solution (salt dissolved in water)
Que-3: Define:
(i) Filtration
(ii) Sublimation
(iii) Evaporation
(iv) Sedimentation
(v) Decantation
(vi) Distillation
Ans-(i) Filtration: It is the process of separating an insoluble solid from a liquid by passing the mixture through a filter.
(ii) Sublimation: It is the process in which a solid changes directly into vapour on heating and the vapour changes back into solid on cooling, without passing through the liquid state.
(iii) Evaporation: It is the process by which a liquid changes into vapour from its surface at temperatures below its boiling point.
(iv) Sedimentation: It is the process in which heavier insoluble particles settle down at the bottom of a liquid when the mixture is left undisturbed.
(v) Decantation: It is the process of separating a liquid from settled insoluble solids by carefully pouring off the clear liquid without disturbing the sediment.
(vi) Distillation: It is the process of separating a soluble solid from a liquid or separating two liquids with different boiling points by heating the mixture and then condensing the vapour formed.
Long Answer Questions
Que-1: Why do we need pure substances ?
Ans- Pure substances are substances that contain only one kind of particle and have a fixed composition. We need pure substances for many important reasons:
(i) Accurate Scientific Experiments: Scientists require pure substances to obtain correct and reliable results. Impurities can affect observations and lead to incorrect conclusions.
(ii) Preparation of Medicines: Medicines must be pure to ensure their safety and effectiveness. Impurities may reduce the medicinal value or cause harmful side effects.
(iii) Industrial Processes: Many industries use pure substances to manufacture products of consistent quality. Impurities can affect the properties and performance of the final product.
(iv) Food Safety: Pure ingredients help maintain the quality, taste, and safety of food products. Contaminated substances may be harmful to health.
Study of Properties: The physical and chemical properties of a substance can be accurately determined only when it is pure.
Que-2: Give reason:
(i) Sand and sawdust cannot be separated by hand picking.
(ii) Magnet is used to separate a mixture of iron and sulphur.
(iii) Alum is used in purification of river water.
Ans- (i) Sand and sawdust cannot be separated by hand picking.
Hand picking is a method used to separate substances when the particles are large enough to be seen and picked out easily by hand. In a mixture of sand and sawdust, both substances are present as very small particles and are mixed closely together. Picking out each particle separately would be extremely difficult, time-consuming, and impractical. Therefore, sand and sawdust cannot be separated by hand picking. They can be separated by using water because sawdust floats on water while sand settles at the bottom.
(ii) Magnet is used to separate a mixture of iron and sulphur.
A magnet is used to separate a mixture of iron and sulphur because iron possesses magnetic properties whereas sulphur does not. When a magnet is brought near the mixture, the iron particles are attracted towards the magnet and can be removed easily, leaving behind the sulphur particles. Thus, the difference in magnetic properties of iron and sulphur makes magnetic separation possible.
(iii) Alum is used in purification of river water.
River water contains many fine suspended impurities such as clay, dust, and other insoluble particles. These particles are very light and do not settle down easily. Alum is added to the water because it causes these tiny suspended particles to stick together and form larger, heavier particles called flocs. These flocs settle at the bottom of the container, making the water clearer. The clear water can then be filtered and further treated for safe use. Therefore, alum is commonly used in the purification of river water.
Que-3: The following diagram shows a method employed for the separation of a mixture. Study the same and answer the following questions:
(i) Label the parts shown as A, B and C.
(ii) Write the name of the method depicted above.
(iii) What kind of mixture is separated by this method?
(iv) How can this process be made faster ?
(v) What is one disadvantage of this process ?
Ans- (i) The parts shown as A, B, and C indicate the following:
A → Liquid
B → Evaporating dish
C → Bunsen burner
(ii) Evaporation is depicted in the given picture.
(iii) Homogeneous solid-liquid mixture is separated by this method.
(iv) Evaporation can be made faster by heating.
(v) In evaporation process, the solvent is lost to the environment in vapour form.
Case Study Type Questions
Que-1: Zainab was helping her mother in the kitchen. She took some rice grains in a bowl, which also contained a few small stones to sort. By mistake, she dropped a container of salt into the bowl, and salt got mixed with the rice grains. Her mother then asked her to separate the rice grains from the stones and the salt so that the rice would be clean and ready to cook for dinner later.
(i) What kind of mixture was formed by Zainab ?Justify your answer.
(ii) How will you separate the stones from the mixture? Name the method used.
(iii) What do you observe when water is added to the remaining mixture of rice grains and salt?
(vi) What will you do to separate rice grains from water?
(v) How will you recover the dissolved salt from the solution?
Ans- (i) The mixture formed is a heterogeneous mixture. Rice grains, small stones and salt are not uniformly mixed and can be seen separately before water is added.
(ii)Stones can be separated by handpicking. This method works because stones are visibly different in size, shape, and color from rice grains.
(iii) When water is added, the salt dissolves in water forming a salt solution, while the rice grains remain undissolved and settle down.
(vi) Rice can be separated from water by decantation (pouring off the water).
(v) The dissolved salt can be recovered by evaporation. When the solution is heated or left to evaporate, water evaporates and the salt remains behind as a solid.
— : End of Exercise II on Pure Substances and Mixtures; Separation of Mixtures Class 6 Concise Chemistry ICSE Solutions :–
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