Question

1.13.If we heat iodine, then it is a

a. Physical change b. chemical change c. no change d. colour change.

1.14.What is the name of the insoluble substance which settles to the bottom of

its container?

a. Solute b. solvent c. sediment d. slag.

1.15.Separation of petroleum into its component is done by

a. Chromatography

b. Sublimation

c. Distillation

d. Fractional distillation.

2. Assertion & reason type 1 X 10 = 10

Directions: in the following questions, a statement of assertion is followed by

a statement of reason.

Mark the correct choice as:

a. If both assertion and reason are true and reason is the correct

explanation of assertion.

b. If both assertion and reason are true but reason is not the correct

explanation of assertion.

c. If assertion is true but reason is false.

d. If both assertion and reason are false.

2.1.Assertion: camphor disappears without leaving any residue.

Reason: camphor undergoes sublimation.

2.2.Assertion: liquids diffuse less easily as compared to gases.

Reason: intermolecular forces are greater in gases.

2.3.Assertion: ice floats on the surface of water.

Reason: the density of both water and ice is same.

2.4.Assertion: the intermolecular forces in solid state are stronger than those in the

liquid state.

Reason: the space between the particles of matter is called intermolecular space.

2.5.Assertion: the rate of evaporation increases with increase in temperature.

Reason: increase in temperature increases the kinetic energy of the particles.

2.6.Assertion: there is no change in the temperature of a substance when it

undergoes a change state though it is still being heated.

Reason: the heat supplied is absorbed either as latent heat of fusion or as latent

heat of vaporisation.

2.7.Assertion: solids do not diffuse in air.

Reason: the particles are closely packed in solids.

2.8.Assertion: naphthalene does not leave any residue when kept open for some

time.

Reason: the conversion of a solid directly into gas is called condensation. ​

Answer 1

Answer:

113.physical change

114.sediment

115.fractional distallation

Answer 2

Answer:

physical change

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