Consider the following heating curve for the generic substance Z.
-About how much energy was added to convert all of this sample of Z from the liquid at the boiling point to the gas at the boiling point?

Question

Consider the following heating curve for the generic substance Z. 
-About how much energy was added to convert all of this sample of Z from the liquid at the boiling point to the gas at the boiling point?

Quizplus · Accepted Answer

To convert a substance from a liquid at its boiling point to a gas at its boiling point requires the heat of vaporization. The heat of vaporization for a substance is the amount of energy required to convert 1 gram of the substance from a liquid to a gas at its boiling point. From the heating curve, it can be seen that the boiling point of Z is approximately 80°C and that the heat of vaporization for Z is approximately 550 cal/g. Therefore, to convert all of the sample of Z from the liquid at the boiling point to the gas at the boiling point, it would require approximately 550 cal/g x 1 g = 550 cal.

Consider the Following Heating Curve for the Generic Substance Z