Question

this graph shows how the vapor pressure of three liquids varies with temperature: graph description with vapor pressure in torr on y - axis and temperature in °c on x - axis, and three curves for tetrahydrofuran, cyclohexane, isopropyl acetate. 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 cyclohexane is put inside a sealed tank containing cyclohexane gas at 63. degree c and 289. torr. after ten minutes, will there be more liquid in the beaker, less liquid, or the same amount?

Explanation:

Step1: Define volatility

Volatility is related to vapor - pressure. Higher vapor - pressure at a given temperature means higher volatility.

Step2: Identify most volatile liquid

From the graph, at a given temperature, tetrahydrofuran has the highest vapor - pressure. So tetrahydrofuran is the most volatile.

Step3: Identify least volatile liquid

Isopropyl acetate has the lowest vapor - pressure at a given temperature, so it is the least volatile.

Step4: Define normal boiling point

The normal boiling point is the temperature at which the vapor - pressure of the liquid is 760 torr.

Step5: Find normal boiling point of tetrahydrofuran

From the graph, when the vapor - pressure of tetrahydrofuran is 760 torr, the temperature is approximately 66°C.

Step6: Find normal boiling point of cyclohexane

When the vapor - pressure of cyclohexane is 760 torr, the temperature is approximately 81°C.

Step7: Find normal boiling point of isopropyl acetate

When the vapor - pressure of isopropyl acetate is 760 torr, the temperature is approximately 89°C.

Step8: Analyze cyclohexane in sealed tank

At 63°C, the vapor - pressure of cyclohexane from the graph is approximately 350 torr. The pressure in the tank is 289 torr which is less than the vapor - pressure at this temperature. So the liquid will evaporate and there will be less liquid in the beaker.

Answer:

most volatile: tetrahydrofuran
least volatile: isopropyl acetate
tetrahydrofuran: 66
cyclohexane: 81
isopropyl acetate: 89
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