Use the vapor pressure curves illustrated here to answer the questions that follow.
(GRAPH CANNOT COPY)
(a) What is the vapor pressure of ethanol $\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\right)$ at $60^{\circ} \mathrm{C} ?$
(b) Considering only carbon disulfide $\left(\mathrm{CS}_{2}\right)$ and ethanol, which has the stronger intermolecular forces in the liquid state?
(c) At what temperature does heptane $\left(\mathrm{C}_{7} \mathrm{H}_{16}\right)$ 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 $400 \mathrm{mm}$ Hg and a temperature of
$70^{\circ} \mathrm{C},$ is each substance a liquid, a gas, or a mixture of liquid and gas?