Question

18. Purification of salt (that we get from sea watacan
be done by
(1) Chromatography (2) Centrifugation
(3) Crystallisation (4) Sublimation
19. The value of -40°C in Kelvin scale is equal to
(1) 233 K
(2) 300 K
(3) 213 K
(4) 313 K
20. The temperature at which a solid melts to become
a liquid at the atmospheric pressure is called its
(1) Freezing point (2) Melting point
(3) Boiling point (4) Triple point​

Answer 1

Answer:18.(3) Crystallisation.

19.(1) 233.

20.(2) Melting point.

Explanation: