Use the observation in the first column to answer the question in the second column. observation question The enthalpy of vaporization of Substance C is bigger than that of Substance D. Which has the higher boiling point? Substance C Substance D Neither, C and D have the same boiling point. It's impossible to know without more information. At 1atm pressure, Substance E boils at 89.°C and Substance F boils at 128.°C. Which has a higher enthalpy of vaporization? Substance E Substance F Neither, E and F have the same enthalpy of vaporization. It's impossible to know without more information. At −3°C, Substance A has a vapor pressure of 147.torr and Substance B has a vapor pressure of 177.torr. Which has a higher boiling point? Substance A Substance B Neither, A and B have the same boiling point. It's impossible to know without more information.

With Vapor pressure (VP) of C = 136 torr and VP of D = 186 torr. Since VP (C) < VP (D), this entaills that one needs to supply more energy to get C into the vapor phase. Hence, enthalpy of vaporization of C will be higher.

2. Substance A

B.pt (A) = 109 C

B,pt (B) = 125 C

Having A boils at a lower temperature than B, this automatically will make A to have a higher vapor pressure.

3. Substance E

Since E has a lower enthalpy of vaporization, it can be brought into the vapor phase with lower energy as compared to F. Hence, E will have a higher vapor pressure.