The normal boiling point of this substance is approximately
A)25°C.
B)140°C.
C)300°C.
D)350°C.

Question

Quizplus · Accepted Answer

The boiling point of a substance is the temperature at which the vapor pressure of the liquid is equal to the external pressure. Since the given substance is under pressure of 1 atm, we can assume that its normal boiling point is around 100°C. However, from the graph, we can see that at this pressure, the substance has not yet reached its boiling point. We can estimate that the boiling point may be around 300°C, as this is the temperature at which the vapor pressure is close to 1 atm. Therefore, the best choice is C.

The Normal Boiling Point of This Substance Is Approximately