A new compound is discovered and a chemistry student undertakes a project to study its behavior when it is heated.
He places 2 grams of this compound in a container fitted with a piston. The piston is exposed to the atmosphere and thus the contents of the container will experience a constant pressure at all times. The walls of the container encase a heating filament, the rate of heat supplied by which can be changed.
Constant heat was supplied at 500 watts to 2 grams of the compound and the rise in temperature was plotted against time.
Constant heat was supplied at 1000 watts to 2 grams of the compound and the rise in temperature was plotted against time.
Note: In the figures, B and D are the melting and the boiling points respectively.
The student then conducted the experiment at various heating rates. He then plotted the times required to reach the melting and boiling points against the rate of heating of the compound.
When the compound was completely converted into gas, the student measured the change in volume with increase in temperature. He plotted the volume of the gas against the temperature of the gas and obtained the following graph.
Which of these is correct about the state of this compound at room temperature?