If liquefied oxygen at 1 atmospheric pressure is heated from 50K to 300k by supplying heat at constant rate. The graph of temperature vs time will be

Options

A.
B.
C.
D.

Answer

C

Explanation

Temperature of liquid oxygen will first increase till boiling point. Then phase change will take place from liquid to gas during which temperature remains same. After this temperature of the gaseous oxygen will further increase. All this is correctly shown by graph (c).