Question

A. Choose the correct option

1. A pure substance is a substance____
a) that consists of only elements
b) that is safe to eat
c) that has only one kind of material
d) that is made up only of atoms

2. Which of these are not mixtures?
(i) air
(i) salt
(iii) sugar
(iv) sea water

a) (i) and (ii)
b) (ii)and (iii)
c) (iii) and (iv)
d) (i) and (iv)

3. In a homogeneous mixture, the______
(i) components cannot be seen separately
(ii) components can be seen separately
(iii) components cannot be separated
(iv) components can be separated

a) (i) and (iii)
b) (ii) and (iv)
c) (ii) and (iii)
d) (i) and (iv)

4.Air is a_____
a homogeneous mixture
b) compound
c) heterogeneous mixture
d) pure substance

5. A mixture of sand and iron fillings is best
separated by____
a) sedimentation
b) winnowing
c) magnetic separation
d) hand picking

6. A mixture of chalk and common salt in water
can be separated by______
a) sedimentation
b) filtration
c) sedimentation and filtration
d) sedimentation and evaporation

7. A mixture of sand, water and mustard oil can
be separated by_____
a) sedimentation, decantation and
separating funnel
b) sedimentation, decantation and
evaporation
C) coagulation, evaporation and distillation
d) evaporation, winnowing and sublimation

8. Salt from sea water is obtained by_____
a) distillation
b) sedimentation
c) evaporation
d) filtration

9.oil and water can be separated using___
a) filter paper
b) distillation
c) evaporation
d) a separation funnel

10.which of the statements are true?
i) the solubility of sugar in water is higher than the solubility of salt in water.
ii) the solubility of salt in water is higher than the solubility of sugar in water
iii) the solubility of sugar in water increases with rise in temperature, whereas that of salt increases very little with rise in temperature
iv) the solubility of both sugar and salt increases at approximately the same rate with increase in temperature.

a) (i) and (iii)
b) (ii) and (iv)
c) (ii) and (iii)
d) (iii) and (iv) ​

Answer 1

Answer:

ABCD ABCDaABCD ABCD

Explanation:

1234