Use the vapor pressure curves illustrated here to answer the questions that follow.

(a) What is the vapor pressure of ethanol, C₂H₅OH, at 60°C?
(b) Considering only carbon disulfide (CS₂) and ethanol, which has the stronger intermolecular forces in the liquid state?
(c) At what temperature does heptane (C₇H₁₆) have a vapor pressure of 500 mm Hg?
(d) What are the approximate normal boiling points of each of the three substances?
(e) At a pressure of 400 mm Hg and a temperature of 70°C, is each substance a liquid, a gas, or a mixture of liquid and gas?

Transcribed Image Text:

Vapor pressure (mm Hg) 900 800 700 600 500 Carbon disulfide Z₂ Ethanol 400 300 200 100 0 10 20 30 0 40 1 1 1 70 Temperature (°C) I 50 60 Heptane 1 1 80 90 1 1 1 100 110