Class 6 chemistry important questions with answers are provided here for Chapter 5 – Separation of Substances. These important questions are based on the CBSE board curriculum and correspond to the most recent Class 6 chemistry syllabus. By practising these Class 6 important questions, students will be able to quickly review all of the ideas covered in the chapter and prepare for the Class 6 annual examinations.
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Class 6 Chapter 5 – Separation of Substances Important Questions with Answers
Fill in the Blanks
i.) When a heavier component of a mixture settles after adding water to it, this process is called ____.
ii.) The two liquids that do not mix with each other are called ____ liquids.
iii.) ____ is the opposite of evaporation.
iv.) Chalk powder can be separated from water by ____.
v.) ____ is the essential condition for winnowing.
Answer.
i.) When a heavier component of a mixture settles after adding water to it, this process is called sedimentation.
ii.) The two liquids that do not mix with each other are called immiscible liquids.
iii.) Condensation is the opposite of evaporation.
iv.) Chalk powder can be separated from water by filtration.
v.) Wind is the essential condition for winnowing.
State True or False
i.) Handpicking should be used only when the quantity of impurities is small.
ii.) At a given temperature, a saturated solution can dissolve more of the solute.
iii.) The sieving method can be used to separate wheat flour from bran.
iv.) Winnowing can separate the heavier and lighter components of a mixture.
v.) Common salt is separated from its solution by decantation.
Answer.
i.) True
ii.) False
iii.) True
iv.) True
v.) False
Match the Following
| Column A | Column B |
|---|---|
| a.) Handpicking | i.) Conversion of water vapours into liquids |
| b.) Threshing | ii.) Separating bran from flour |
| c.) Winnowing | iii.) Separating larger size impurities |
| d.) Sieving | iv.) Separating butter from milk |
| e.) Sedimentation | v.) Conversion of water into its vapours |
| f.) Evaporation | vi.) Separating grains from the stalks |
| g.) Condensation | vii.) Settling of heavier components at the bottom |
| h.) Churning | viii.) Separation by wind or by blowing air |
Answer.
| Column A | Column B |
|---|---|
| a.) Handpicking | iii.) Separating larger size impurities |
| b.) Threshing | vi.) Separating grains from the stalks |
| c.) Winnowing | viii.) Separation by wind or by blowing air |
| d.) Sieving | ii.) Separating bran from flour |
| e.) Sedimentation | vii.) Settling of heavier components at the bottom |
| f.) Evaporation | v.) Conversion of water into its vapours |
| g.) Condensation | i.) Conversion of water vapours into liquids |
| h.) Churning | iv.) Separating butter from milk |
Very Short Answer Questions
Q1. What is the use of a strainer in separating substances?
Answer. A strainer is a type of sieve used to separate liquid from solid.
Q2. Which process is used to separate cream from curd?
Answer. Centrifugation.
Q3. List some of the materials that are used as filters.
Answer. Cotton, ceramic, filter cloth, and filter paper are some materials used as filters.
Q4. Which method can be used to separate salt from seawater?
Answer. Evaporation.
Q5. Which process is considered the opposite of evaporation?
Answer. Condensation.
Q6. How can husk be removed from wheat?
Answer. By winnowing.
Q7. Which method is used to separate stones from grains?
Answer. Handpicking.
Q8. Which method is used to separate two liquids that do not mix with each other?
Answer. Separating funnel.
Q9. Name the liquid that is known as the universal solvent.
Answer. Water.
Q10. What is the process for separating the heavier and lighter components of a mixture?
Answer. Winnowing.
Short Answer Questions
Q1. Define winnowing.
Answer. Winnowing is the process of separating heavier components of a mixture from lighter components using wind. This method is used to separate grains from the husk after the threshing process.
Q2. Define sedimentation.
Answer. Sedimentation is the separation of solids from liquids. This process is carried out when the heavier component of a mixture settles after water is added to it.
Q3. Define decantation.
Answer. Decantation is the process of separating liquid from solid and other immiscible non-mixing) liquids by removing the liquid layer on top of the solid or liquid layer just below it. The process can be carried out by tilting the mixture after pouring out the top layer.
Q4. What are evaporation and condensation?
Answer. Evaporation is the conversion of a liquid state (water) into a gaseous state (vapour). Condensation is the opposite process that converts gaseous state water (vapour) to a liquid state (water).
Q5. What is a saturated and unsaturated solution?
Answer. A saturated solution is one that cannot dissolve any more solute at that temperature.
An unsaturated solution is one in which the solute can be dissolved at any fixed temperature.
Q6. When is the handpicking method used?
Answer. Handpicking method is used for separating undesirable components that differ in shape, size, and colour and are present in small quantities.
Q7. Define threshing.
Answer. The process of separating grains from the stalk by beating is known as threshing. Since the grains are weakly attached to the stalk, they separate when the stalks are beaten on the ground.
Q8. What is a mixture?
Answer. A mixture is a mixture of two or more substances that do not react with one another. Examples include sugar and water, sugar and sand, and so on.
Q9. Why is it necessary to separate substances from mixtures?
Answer. It is necessary to separate substances from mixtures in order to obtain pure substances for various purposes.
Q10. What are the five methods for separating substances from their mixtures?
Answer. The following are five methods for separating substances:
- Winnowing
- Sieving
- Handpicking
- Threshing
- Decantation
Q11. Define handpicking.
Answer. Handpicking is a method of separation in which impurities in a mixture that differ from the useful material are hand-picked and removed.
For example, stone pieces can be separated from wheat or rice by handpicking.
Q12. How will you separate a mixture of oil and water?
Answer. Since oil is lighter than water, it will float on it. Two distinct layers form, and oil is slowly allowed to flow into another container, where it is separated from the water. This method to separate oil and water is called a separating funnel.
Long Answer Questions
Q1. Differentiate between sedimentation and decantation with a suitable example.
Answer. Sedimentation is the process by which the heavier components of a mixture settle down. For example, when a sand-water mixture is allowed to stand undisturbed for some time and sand settles at the bottom.
Decantation is the process of separating the liquid portion of a mixture when the heavier component settles as sediments at the bottom. In other words, it is the process of moving a liquid from one container to another while leaving the sediments at the bottom alone.
For example, sand settles at the bottom of a container when a mixture of sand and water is allowed to stand. The upper portion of the container contains water. This can be separated from the sand at the bottom simply by pouring it into another container without the use of any other separating device. This is referred to as decantation.
Q2. Describe the process of separating salt from seawater.
Answer. Many salts are present in seawater. When seawater is allowed to stand in shallow pits, sunlight evaporates the water, which slowly turns into water vapour. The water evaporates completely in a few days, leaving behind the solid salts. After further purification, common salt is obtained from this salt mixture.
Q3. Explain how to separate the following mixture:
i.) Sand and husk
ii.) Wheat, sugar and stalk
iii.) Water and petrol
iv.) Rice and salt
v.) Sand and salt
Answer.
i.) Sand and husk mixture: Sand and husk can be separated using the winnowing method.
ii.) Wheat, sugar, and stalk mixture: The winnowing method can be used to separate the stalk from the mixture because it is lighter than the other two components and separates easily. Because wheat and sugar have different sizes, sieving can be used to separate them.
iii.) Water-petroleum mixture: Water does not dissolve in petrol. As a result, it can be separated using a separating funnel.
iv.) Rice and salt mixture: Rice and salt can be separated by sieving.
v.) Sand and salt mixture: When sand and salt are mixed with water, salt dissolves in water, and sand solution can be separated by sedimentation, decantation, and filtration. The common salt is then separated using evaporation.
Q4. Explain the method of separation of solid-liquid mixtures.
Answer. Filtration is used to separate solid and liquid mixtures when the solid particles are too large to pass through a filter paper.
Solid particles in a liquid can sometimes be so small that they can pass through filter paper. The filtration technique cannot be used to separate such particles. Centrifugation is used to separate such mixtures. Centrifugation is the process of separating insoluble materials from a liquid when filtration does not work well. The centrifugation is determined by the particle size, shape, and density.
Sedimentation and decantation can be used to separate heavy solid particles. If the mixture is left undisturbed for an extended period of time, the solid particles settle to the bottom. They can then be separated from the liquid by decantation.
Q5. What is sieving? Explain how it is done.
Answer. Sieving is a separation method used to separate substances of varying sizes that cannot be separated by handpicking.
The difference in the size of the solid particles is the basis for the principle.
Separation Technique – By passing the mixture through a sieve, large particles are separated from small or finer particles. The sieve is made of wood and has a metal mesh at the bottom. When the sieve is shaken, the mixture is added from the top as the larger particles remain above and the finer particles collect below.
For example, Impurities such as husk and stones are removed from wheat before it is ground in a flour mill.
Read Also:
- Separation of Substances
- Methods of Separation
- Class 6 Chemistry Worksheet on Chapter 5 Separation of Substances – Set 1
- Class 6 Chemistry Worksheet on Chapter 5 Separation of Substances – Set 2
- Class 6 Chemistry Worksheet on Chapter 5 Separation of Substances – Set 3
- Class 6 Chemistry Chapter 5 Separation of Substances MCQs
- Separation Techniques Questions
- Separation Questions
- Chemistry Concept Questions and Answers
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