We are glad to present the Cordova Learning Science solution for class 6. Things that we see around us in our daily life are mostly mixtures. For example, air, water, soil, food items, milk, paint, fog etc. Often we need to separate the substances from their mixture. This is basically because of two reasons,
a) To obtain useful components and
b) To remove harmful/undesirable substances.
In this blog we are going to solve all the questions related to separation of mixtures, chapter’s exercise and also some worksheets to practice our gained knowledge.
Section A : Worksheet [ learning science class 6 solution ]
Learning science class 6 solutions
A. Tick the correct options :
1. A soluble solid from a mixture of solid and liquid is obtained by
a) filtration b) condensation c) evaporation d) decantation
Ans : c) evaporation
2. A mixture of sand and water can be separated by
a) distillation b) evaporation c) filtration d) condensation
Ans : c) filtration
3. A mixture of mustard oil and water can be separated by
a) sublimation b) separating funnel c) filtration d)evaporation
Ans : b) separating funnel
4. What is formed when we dissolve a substance in water?
a) solute b) mixture c) solution d) solvent
Ans : c) solution
5. A solution in which no more substance can be dissolved at a given temperature is called a/an
a) saturated b) unsaturated c) miscible d) immiscible
Ans : a) saturated
6. After harvesting, the grains of food crops are separated by
a) threshing b) hand-picking c) winnowing d) sieving
Ans : a) threshing
learning Science class 6 solutions
B. Circle the odd ones. Give reason for your choice :
1. hand-picking evaporation winnowing threshing
Ans : Odd one– evaporation
Reason– because evaporation is used to separate soluble impurities.
2. sedimentation decantation winnowing condensation
Ans : Odd one– winnowing
Reason– because winnowing is used to separate heavier and lighter components of a mixture by wind while others are used to separate soluble impurities.
3. sand sugar chalk-powder water
Ans : Odd one- water
Reason- because water is liquid and universal solvent and all others are solids and solutes.
4. solute solvent solution sand
Ans : Odd one- sand
Reason- because all other than sand are parts of a mixture.
learning science class 6 solutions
C. Fill in the blanks :
1. The mixture having components of different sizes are separated by the process of sieving.
2. Grains and husk can be separated by using winnowing.
3. Sedimentation and decantation can be used for separating insoluble solids from liquid.
4. Sieving is used to separate stones and pebbles from sand at construction site.
5. The extent to which a substance gets dissolved in a liquid is called its solubility .
Section – B
A. Multiple Choice questions (MCQs)
1. In the process of winnowing of wheat grains mixed with tiny bits of paper, which will fall at a greater distance?
a) wheat grains b) bits of paper c) both of these d) none of these
Ans : b) bits of paper
2. In decantation, we can pour the clean water into another beaker gently with the help of a________________.
a) funnel b) glass tube c) glass rod d) beaker
Ans : c) glass rod
3. During filtration, what do we obtain on filter paper?
a) filtrate b) muddy water c) residue d) clear water
Ans : c) residue
4. The salt from sea water is made by the process of _________________.
a) evaporation b) filtration c) distillation d) condensation
Ans : a) evaporation
learning science class 6 solutions
B. Very Short Answer Question:
1. Which method is used to separate grains from stalk?
Ans : Threshing is used to separate grains from stalk.
2. Give an example from our daily life where the processes of sedimentation and decantation are used.
Ans : We use the process of sedimentation and decantation when we wash the vegetables or grains, as we put them in the water and after a while the heavier impurities sediment to the bottom. Then we carefully remove the grains or veggies from the water.
3. Name any two processes used to separate soluble components from a mixture.
Ans : Evaporation and distillation are used to separate soluble components from a mixture.
4. Name the method by which we can separate seeds and pulp from the fruit juice.
Ans : We can separate seeds and pulp from fruit juice by the process of filtration.
5. What is meant by condensation?
Ans : The process of changing the gaseous state of a substance to its liquid state is called condensation.
6. What are the two types of mixtures?
Ans : The two type of mixtures are – Homogeneous mixtures and Heterogeneous mixtures.
cordova learning science class 6 solutions
C. Short Answer Questions:
1. (a) Why is water called the universal solvent? (b) Define solubility. How can it be increased in water?
Ans : Water is called the universal solvent because most of the substances gets dissolved in it. The extent to which a substance gets dissolved in a liquid is called its solubility. It can be increased by increasing the temperature of water.
2. Define the terms: (a) sedimentation (b) decantation.
Ans : a) Sedimentation : The process of settling down of heavier insoluble particles at the bottom of a liquid is called sedimentation.
b) Decantation : The process of transfer of the clear liquid from one beaker to another without disturbing the sediment at the bottom is called decantation.
3. Can water dissolve any amount of a substance? Explain.
Ans : No, water can not dissolve any amount of a substance. After an extent the solute does not get dissolved in water instead it starts to settle down at the bottom of water.
4. What is loading?
Ans : The process of increasing the rate of sedimentation in a suspension by adding some chemicals like alum to it, is called loading.
5. What is the difference between filtrate and residue?
Ans : The difference between filtrate and residue is that the filtrate is the clear liquid that we get after filtration and residue is the unwanted bigger sized particles that remain on the filter paper.
6. Soni is helping her mother and accidentally she mixes the arhar dal with gram seeds and rice flour. Her brother helps her in separating the thing from each other.
(a) Which method they would have used to separate things?
Ans : They would have used the hand picking method to separate the two things.
(b) What value do you learn from Soni’s brother?
Ans : We can learn to help our moms and other family members in household works by Soni’s brother.
learning science class 6 solution
D. Long Answer Questions:
1. (a) How will you separate the following: mustard seeds and common salt, chalk powder and water, sand and water, grains and stones?
Ans : We will separate the following mixtures by these methods-
|Mustard seeds and common salt||Sieving|
|Chalk powder and water||Sedimentation and decantation|
|Sand and water ||Filtration|
|Grains and stones||Hand picking|
(b) How is fine sand separated from larger particles? Explain.
Ans : Fine sand particles can be separated from larger particles by sieving because it is a convenient and easy method of separating mixtures that have components of different sizes.
2. How will you obtain clear water from a sample of muddy water?
Ans : We will put the sample of muddy water undisturbed for a couple of hours and when the mud or sediment will settle down at the bottom of the vessel we will pour the clear water in another vessel gently with help of a glass rod. This process is known as sedimentation and decantation.
3. What happens if a saturated solution of a substance and water is (a) heated and (b) cooled?
Ans : a) When a saturated solution of a substance and water is heated, the undissolved substance at the bottom starts getting dissolved.
b) When a saturated solution of a substance and water is cooled, the dissolved substance starts to settle down at the bottom.
This concludes that solubility of a solid substance in water increases with rise in temperature and vice versa.
4. (a) Why do we need to separate substances from mixture?
Ans : We need to separate substances from mixtures-
1. To remove harmful substances such as pieces of stones and insects from grains.
2. To obtain useful components such as separation of crude petroleum to obtain petrol, diesel, kerosene, wax etc.
3. To remove undesirable substances such as filtering tea leaves from tea.
(b) Differentiate between homogeneous and heterogeneous mixtures with examples.
Ans : The components of homogeneous mixtures are uniformly distributed and each part of the mixture has the same properties. Alcohol and water, salt and water, air etc are some examples of homogeneous mixtures.
The constituents of heterogeneous mixtures do not get mixed uniformly and each part of the mixture has different properties. Butter and water, chalk powder and water, soil etc are some examples of heterogeneous mixture.