Question

At 298 K, if the vapour pressure of pure liquids toluene, benzene, chloroform and dichloromethane are 60, 160, 200 and 415 torr respectively. Then which liquid is having high boiling point?

• A. Toluene
• B. Benzene
• C. Chloroform
• D. Dichloromethane

Hint:

Remember the inverse relationship between vapor pressure and boiling point. Liquids with strong intermolecular forces tend to have lower vapor pressures and higher boiling points because more energy is required to overcome these forces and allow the molecules to escape into the gas phase.

Answer 1

The Correct Option is A

Step 1: Understand the relationship between vapor pressure and boiling point.
The boiling point of a liquid is the temperature at which its vapor pressure equals the external pressure (typically atmospheric pressure). Liquids with lower vapor pressures at a given temperature require more energy (higher temperature) to reach the external pressure and thus have higher boiling points.
Step 2: List the vapor pressures of the given liquids at 298 K. \begin{itemize} \item Toluene: 60 torr \item Benzene: 160 torr \item Chloroform: 200 torr \item Dichloromethane: 415 torr \end{itemize}
Step 3: Identify the liquid with the lowest vapor pressure.
Comparing the vapor pressures, toluene has the lowest vapor pressure (60 torr) at 298 K.
Step 4: Relate the lowest vapor pressure to the highest boiling point.
Since toluene has the lowest tendency to vaporize at 298 K, it will require a higher temperature to reach atmospheric pressure compared to the other liquids. Therefore, toluene has the highest boiling point. Final Answer: The final answer is $\boxed{Toluene}$