Question

ASSERTION AND REASON DIRECTION : In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as: (a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A). (b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A). (c) Assertion (A) is true but reason (R) is false. (d) Assertion (A) is false but reason (R) is true. Questions: 1. Assertion : Camphor disappears without leaving any residue. Reason : Camphor undergoes sublimation. (1 Point) Option a Option b Option c Option d 2. Assertion : Liquids diffuse easily as compared to gases. Reason : Inter molecular forces are greater in liquids. (1 Point) Option a Option b Option c Option d 3.Assertion : There is no change in the temperature of a substance when it undergoes a change of state through it is still being heated. Reason : The heat supplied is absorbed either as latent heat of fusion or as latent heat of vaporization. (1 Point) Option a Option b Option c Option d 4.Assertion : During evaporation of liquids, the temperature remains unaffected. Reason : Kinetic energy of the molecules is directly proportional to temperature. (1 Point) Option a Option b Option c Option d 5.Assertion : It is easier to cook food at high altitudes. Reason : The boiling point of water decreases at high altitudes. (1 Point) Option a Option b Option c Option d 6.Assertion : A gas can be easily compressed by applying pressure. Reason : Since the inter-particle spaces in the gaseous state are very small, they cannot be decreased by applying pressure. (1 Point) Option a Option b Option c Option d 7.Assertion : The inter molecular forces in solid state are stronger than those in the liquid state. Reason : The space between the particles of matter is called inter molecular space. (1 Point) Option a Option b Option c Option d 8.Assertion : When a beam of light is passed through a colloidal solution placed in a dark place the path of the beam becomes visible. Reason : Light gets scattered by the colloidal particles. (1 Point) Option a Option b Option c Option d 9.Assertion : A solution of table salt in a glass of water is homogeneous. Reason : A solution having different composition throughout is homogeneous. (1 Point) Option a Option b Option c Option d 10.Assertion : A true solution do not exhibits Tyndall effect. Reason : A true solution is a heterogeneous mixture.Immersive Reader (1 Point) Option a Option b Option c Option d

Answer 1

Answer:

1) A

2) D

3) A

4) B

5) D

6) C

7) B

8) A

9) C

10) C

Explanation:

Sublimation refers to the direct change of a substance from solid to gas without passing through a liquid stage. Hence if camphor changes directly from solid to gas, camphor is a sublime substance.

Gases have a higher rate of diffusion than liquids because liquids have greater intermolecular forces while the intermolecular forces in a gas is negligible.

When a substance is heated, a point comes in which heat is supplied but the temperature of the body does not change. This is the point of phase change and the heat supplied at this point may be referred to as latent heat of fusion or vaporization depending on the particular process going on.

While it is true that evaporation occurs at all temperatures and the kinetic energy of molecules is directly proportional to the temperature of a body but the later statement does not explain the former. Rather evaporation occurs because some particles at the surface of the liquid are more energetic and escape due to unbalanced attractive forces acting on them.

Due to decrease in temperature, it takes a longer time to cook food at high altitudes but a lesser time to boil water at higher altitudes.

Gases are easily compressible by applying pressure because gases occupy negligible volume compared to the volume of the container. There is a significant inter particle space between gas particles.

The solid state contains the strongest degree of intermolecular forces. However, the reason offered, though correct, is not the correct explanation of the assertion stated.

This is the Tyndall effect. Colloidal particles scatter light rays and the path of the light becomes visible in the colloidal solution.

Salt solution is homogeneous. A homogeneous solution contains only one phase throughout. If it has a different composition, the solution is heterogeneous. Hence the explanation is false.

A true solution will not exhibit Tyndall effect because the particles are less than colloidal size. A true solution cannot be a heterogenous mixture hence the reason is false.