The questions below consists of an assertion and a Reason. Use the key to choose the appropriate answer.
Q1: Assertion: When the heavier component in a mix settles after water is added to it the process is called sedimentation.
Reason: When the water along with the dust is removed the process called decantation.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Ans: (b)
The assertion is correct in stating that when the heavier component settles in a mixture after water is added, it's called sedimentation. However, the reason is not a correct explanation. Decantation is indeed a process for removing the liquid (in this case, water) along with the dust or solid particles that have settled. Still, it does not explain why the process of settling itself is called sedimentation.
Q2: Assertion: for separation of heavier and lighter components of a mixture by wind or by blowing air.
Reason: The process which is used to separate rain from stalks are known as winnowing.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Ans: (c)
The assertion is correct in describing the separation of heavier and lighter components using wind or blowing air. However, the reason is not correct. Winnowing is indeed the process used to separate grain from stalks, but it is not related to separating rain from stalks. The reason incorrectly connects winnowing with rain, which is not the case.
Q3: Assertion: Separation of stones from rice is one of the separation method.
Reason: The above separation method is handpicking method of separation.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Ans: (a)
Both the assertion and the reason are correct. Separating stones from rice is a common separation method in agriculture. The reason accurately explains that this method is called the handpicking method, where individuals manually pick out stones from the rice. The reason provides a valid explanation for the assertion.
Q4: Assertion: evaporation can be used to separate a solid dissolved in a liquid.
Reason: Evaporation is the process in which liquid gets converted into it's vapour.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Ans: (a)
Both the assertion and the reason are correct. Evaporation is a process in which a liquid (in this case, the solvent) is converted into its vapor form, leaving behind any dissolved solid substances. This is a valid method for separating a solid dissolved in a liquid, as the reason correctly explains.
Q5: Assertion: Evaporation is a method used to separate a solid dissolved in a liquid.
Reason: The process of evaporation helps to remove the solvent and leave behind the solute.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Ans: (a)
Evaporation is a process where a liquid changes to a gas. When a solution is heated, the solvent evaporates leaving the solute behind. This method is used to separate a solid substance that has been dissolved in a liquid.
Q6: Assertion: Handpicking is a method used to separate substances of different sizes.
Reason: In handpicking, substances are separated based on their size.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Ans: (b)
Handpicking is a method used to separate substances, but it is based on the difference in size and also visual appearance, not just size.
Q7: Assertion: Sieving is a method used to separate substances of different sizes.
Reason: In sieving, the fine particles pass through the holes of the sieve while the bigger particles remain on the sieve.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Ans: (a)
Sieving is a process where a mixture is passed through a sieve. The fine particles pass through the sieve, and the larger particles remain on the sieve, thereby separating the substances.
Q8: Assertion: Sedimentation is a method used to separate insoluble solids from liquids.
Reason: Sedimentation is a process where the heavier solid particles settle down at the bottom of the container.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Ans: (a)
In sedimentation, the heavier insoluble solids in a liquid settle down at the bottom when left undisturbed. This is used to separate the solid particles from the liquid.
Q9: Assertion: The process of condensation is used in the distillation method.
Reason: In distillation, the vapor is cooled down to get the substance back in its liquid form.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Ans: (a)
Distillation is a process where a liquid is boiled to produce a vapor that is then condensed back into a liquid. The process of condensation is used to cool down the vapor and get the substance back in its liquid form.
