Question

The following questions consists of two statements- Assertion (A) and Reason(R). Answer these questions selecting appropriate option given below: a) Both A and R are true and R is correct explanation of A b) Both A and R are true and R is not correct explanation of A c) A is true but R is false d) A is false but R is true 11. Assertion: Conversion of solid into vapour without passing through the liquid state is called vaporisation. Reason: Conversion of solid into liquid is called sublimation. 12. Assertion: During summer, water kept in an earthen pot becomes cool. Reason: the process of turning from liquid into vapour. 13. Assertion: When a gas jar full of air is placed upside down on a gas jar full of bromine vapours, the red-brown vapours of bromine from the lower jar go upward into the jar containing air. Reason: Bromine is heavier than air 14. Assertion: Pure substances contain different kind of particles. Reason: Pure substances have the same composition throughout 15. Assertion: When the liquid is spun rapidly, the denser particles are forced to the bottom and the lighter particles stay at the top Reason: Centrifugation is a technique that helps to separate mixtures by applying centrifugal​

Answer 1

Answer:

11) a option is correct

12) b is correct option

13) c option is correct

14) c is the correct option

15) a is correct option

Answer 2

1)Assertion: Conversion of solid into vapour without passing through the liquid state is called vaporisation.

Reason: Conversion of solid into liquid is called sublimation.

Answer: d) A is false but R is true

Explanation: The process of conversion of solid to gas sate skipping the liquid state is called sublimation and not vapourisation.

2)Assertion: During summer, water kept in an earthen pot becomes cool. Reason: the process of turning from liquid into vapour.

Answer :a) Both A and R are true and R is correct explanation of A.

Explanation: During evaporation the heat also escapes.

3) Assertion: When a gas jar full of air is placed upside down on a gas jar full of bromine vapours, the red-brown vapours of bromine from the lower jar go upward into the jar containing air.

Reason: Bromine is heavier than air.

Answer: a) Both A and R are true and R is correct explanation of A.

Explanation: The bromine molecules being heavier settle at the bottom of the jar. It also diffuses and thus both the jar appear to be brownish red.

4)Assertion: Pure substances contain different kind of particles.

Reason: Pure substances have the same composition throughout

Answer: A is false but R is true

Explanation: Pure substances contain only one type of particles which are uniformly spread.

5)Assertion: When the liquid is spun rapidly, the denser particles are forced to the bottom and the lighter particles stay at the top

Reason: Centrifugation is a technique that helps to separate mixtures by applying centrifugal​.

Answer :Both A and R are true and R is correct explanation of A

Explanation: Centrifugation separates denser particles from lighter particles.

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