Question

this graph shows how the vapor pressure of three liquids varies with temperature: use the graph to answer the following questions: which liquid is the most volatile? which is the least volatile? what is the normal boiling point of each liquid? note: your answer must be within 1°c of the exact answer to be graded correct. suppose a beaker of methanol is put inside a sealed tank containing methanol gas at 56. degree c and 317. torr. after ten minutes, will there be more liquid in the beaker, less liquid, or the same amount?

Explanation:

Step1: Understand volatility - vapor pressure relation

Higher vapor - pressure at a given temperature means higher volatility.

Step2: Compare vapor pressures at a temperature

At any given temperature on the graph, acetone has the highest vapor pressure, so it is the most volatile. Benzene has the lowest vapor pressure, so it is the least volatile.

Step3: Recall normal boiling - point definition

Normal boiling point is when vapor pressure = 760 torr.

Step4: Find normal boiling points from graph

For acetone, the temperature when vapor pressure is 760 torr is approximately 56°C. For methanol, it is approximately 65°C. For benzene, it is approximately 80°C.

Step5: Compare vapor pressure and external pressure for methanol

At 56°C, the vapor pressure of methanol from the graph is approximately 400 torr. The external pressure is 317 torr. Since the vapor pressure of methanol at 56°C is higher than the external pressure in the tank, more liquid will evaporate, and there will be less liquid in the beaker.

Answer:

most volatile: acetone
least volatile: benzene
acetone: 56
methanol: 65
benzene: 80
less