Question

The melting and boiling point of substances are given below:
Substance MP °C BP°C
Nitrogen -210 -196
Carbon disuphide -112 46
Amonia -78 -34
Bromine -7 59
Phosphorus 44 280
Mercury(II)Chloride 276 302
Room temperature is 20 degrees
celsius
a) Which *element* will condense when cooled to room temperature from 100°C
b) Which *compound* will freeze first on cooling from room temperature to a very low temperature?
c) Which of the six substances is a liquid over the widest range of temperature?

Answer 1

(a) Bromine will condense at 59 °C when cooled from 100 °C to room temperature .

(b) Ammonia will freeze first at -78 °C when cooled from room temperature to a lower temperature.

Carbon disulfide freezes at -112 °C and nitrogen freezes at -210 °C.

(c) Phosphorus is a liquid over the widest range of temperatures

(280 °C – 44 °C = 236 °C).

None of the other substances has that wide a liquid range.