Worksheet answers F-O.pdf Worksheet of the physics chapter Separation Of Substances (Class 6 CBSE)

Worksheet answers F-O.pdf Worksheet of the physics chapter Separation Of Substances (Class 6 CBSE)

1. F. Fill in the blanks with Answers and Explanations
1. A solution in which no more substance can be dissolved at a given temperature
are called ____________ solution.
án Answer: Saturated solution
n Explanation: When we keep adding sugar to water, after a point the sugar stops
dissolving and settles down. That mixture is called a saturated solution because
the water cannot take in any more sugar at that temperature.
2. A mixture of mustard oil and water can be separated by ____________.
án Answer: Decantation (or using a separating funnel)
n Explanation: Oil and water do not mix; they form two different layers. Oil floats
on top of water. We can pour (decant) the oil layer off or use a separating funnel to
take out water from below.
3. A ____________ is formed when we dissolve a substance into water.
án Answer: Solution
n Explanation: When salt or sugar dissolves in water, they spread out evenly and
make a uniform mixture. This kind of mixture is called a solution.
4. Water is a ____________ solvent.
án Answer: Universal solvent
n Explanation: Water can dissolve many substances like salt, sugar, lemon juice,
etc. Because it can dissolve so many things, it is called the universal solvent.
5. Solubility of solids ____________ with increase in temperature.
án Answer: Increases
n Explanation: If we heat water, more sugar or salt can dissolve in it. This means
the solubility of solids increases when temperature increases.

2. G. Differentiate between
1. Solute and Solvent
án Answer:
- Solute: The substance that gets dissolved in a liquid.
- Solvent: The liquid in which the solute dissolves.
n Explanation: If we put sugar in water, sugar is the solute (because it dissolves),
and water is the solvent (because it does the dissolving). Together, they make a
solution.
2. Saturated solution and Unsaturated solution
án Answer:
- Saturated solution: A solution that cannot dissolve any more solute at a given
temperature.
- Unsaturated solution: A solution that can still dissolve more solute at that
temperature.
n Explanation: If we add sugar to water and keep stirring, at first all the sugar
dissolves. This is an unsaturated solution because more sugar can still dissolve.
But after some point, the sugar stops dissolving and settles at the bottom. Then
the solution is saturated, because the water cannot take in any more sugar at that
temperature.

3. H. State whether the following statements are true
or false
1. Mixture of oil and water can be separated using separating funnel.
án Answer: True
n Explanation: Oil and water are immiscible (they don’t mix). A separating funnel
can separate them easily because oil floats on water and they form two layers.
2. The substance present in a solution in small quantity is a solvent.
án Answer: False
n Explanation: The substance present in small quantity is called the solute (like
sugar in sugar-water). The substance present in large quantity is the solvent (like
water).
3. In sugar solution, sugar is a solute.
án Answer: True
n Explanation: Sugar dissolves in water. Since it is the substance being dissolved,
sugar is the solute.
4. Solubility of all the substance increases with increase in temperature.
án Answer: False
n Explanation: Most solids dissolve better in hot water (like sugar or salt). But
gases (like carbon dioxide in soda) dissolve less when temperature increases. So,
it is not true for all substances.
5. Water is a universal solvent.
án Answer: True
n Explanation: Water can dissolve many substances like sugar, salt, lemon juice
etc. Because of this property, it is called the universal solvent.

4. Science Questions and Answers
I. Give Reasons.
1. Water is called a universal solvent.
án Answer: Because water can dissolve many different substances.
n Explanation: Water dissolves sugar, salt, lemon juice, and many other materials. Since it can
dissolve more substances than most other liquids, it is called the universal solvent.
2. Alum is used in the process of sedimentation.
án Answer: Because alum helps tiny dirt particles settle down.
n Explanation: In muddy water, dirt particles are very small and do not settle quickly. When alum is
added, it makes the particles stick together and become heavier. These heavier particles settle
down faster, making the water clearer.
J. Answer the following.
1. What is a solution?
án Answer: A solution is a uniform mixture formed when a solute dissolves in a solvent.
n Explanation: For example, when sugar (solute) dissolves in water (solvent), they mix evenly to
form a solution.
2. How can we increase the solubility of a substance?
án Answer: By increasing the temperature or stirring the solution.
n Explanation: If we heat water, more sugar or salt can dissolve in it. Stirring also helps the solute
spread faster in the solvent. So, solubility increases with heat and stirring.

5. Science Questions and Answers - Separation of
Substances
K. Name the method used to separate the following mixtures?
1. Stones and Sand
án Answer: Handpicking
n Explanation: Stones are larger than sand particles, so they can be separated easily by hand.
2. Oats and Milk
án Answer: Filtration
n Explanation: Oats do not dissolve in milk. By using a strainer or filter, oats can be separated from
the milk.
3. Kerosene Oil and Water
án Answer: Separation using a separating funnel (Decantation)
n Explanation: Kerosene and water are immiscible liquids (do not mix). Since kerosene is lighter, it
floats on water and can be separated.
4. Salt and Water
án Answer: Evaporation
n Explanation: Salt dissolves in water to form a solution. On heating, water evaporates and salt
remains behind.
5. Iron Nails and Sand
án Answer: Magnetic Separation
n Explanation: Iron nails are magnetic, but sand is not. So, a magnet can easily separate iron nails
from sand.
L. Answer the following in one word.
1. The process of pouring the clear liquid without disturbing the sediment is known as
án Answer: Decantation
n Explanation: In this method, clear liquid is carefully poured out from above the sediment without
disturbing it.
2. The method by which a solution of copper sulphate and water is separated is
án Answer: Evaporation
n Explanation: On heating, water evaporates and blue crystals of copper sulphate remain.
3. This substance is used to increase the rate of sedimentation
án Answer: Alum
n Explanation: Alum helps tiny dirt particles clump together, making them heavier so they settle
faster.
4. A mixture in which all the components are uniformly distributed
án Answer: Solution
n Explanation: In a solution, solute and solvent mix uniformly. Example: Sugar solution.
5. The ability of a substance to dissolve in water to form a solution is called
án Answer: Solubility

6. n Explanation: Solubility is the property of a substance (solute) to dissolve in a given solvent like
water.

7. Science Questions and Answers - Mixtures and
Solutions
M. Answer the following in few words.
1. Two examples of heterogeneous mixture.
án Answer: Sand and water, Oil and water
n Explanation: In a heterogeneous mixture, the components do not mix uniformly and can be seen
separately. For example, sand settles in water, and oil floats on water.
2. Two useful products we get by fractional distillation of petroleum.
án Answer: Petrol, Diesel
n Explanation: Fractional distillation separates petroleum into useful products like petrol, diesel,
kerosene, and LPG, which are used as fuels and raw materials in industries.
3. Two types of solution.
án Answer: Solid solution, Liquid solution
n Explanation: In a solid solution (like alloys), metals mix uniformly. In a liquid solution (like salt
water), solids dissolve in liquids to form a uniform mixture.
N. Match the following.
1. Yellow dal and papaya seeds ® b. Hand Picking
n Explanation: Papaya seeds can be removed from dal by handpicking as they are large and
visible.
2. Fruit juice and pulp ® a. Sieving
n Explanation: A sieve or strainer separates the pulp from juice.
3. Air ® e. Mixture
n Explanation: Air is a mixture of gases like nitrogen, oxygen, and carbon dioxide.
4. Water vapour changes into liquid ® c. Condensation
n Explanation: The cooling of water vapour into liquid form is called condensation.
5. Chlorine ® d. Disinfectant
n Explanation: Chlorine is commonly used to kill germs in water, making it a disinfectant.
O. Give one example of each.
1. Solid-solid mixture
án Answer: Brass (Copper + Zinc)
n Explanation: Brass is an alloy where two solids (metals) are mixed uniformly.
2. Solid-liquid mixture
án Answer: Salt in water
n Explanation: When salt dissolves in water, it forms a solid-liquid mixture called a solution.
3. Liquid-liquid mixture
án Answer: Milk and water
n Explanation: When two liquids like milk and water are mixed, they form a liquid-liquid mixture.