Problem 262
If the vapor pressure of methy1 alcohol, \(\mathrm{CH}_{3} \mathrm{OH}\), is \(0.0526\) atm at \(5.0^{\circ} \mathrm{C}\) and \(0.132 \mathrm{~atm}\) at \(21.2^{\circ} \mathrm{C}\), what do you predict the normal boiling point will be?
Problem 265
At a 4000 -m altitude the atmospheric pressure is about \(0.605 \mathrm{~atm}\). What boiling point would you expect for water under these conditions?
Problem 266
Liquid nitrogen is an excellent bath for keeping temperatures around \(77^{\circ} \mathrm{K}\), its normal boiling point. What pressure would you need to maintain over the liquid nitrogen if you wanted to set the bath temperature at \(85^{\circ} \mathrm{K} ?\) Heat of vaporization is about \(5560(\mathrm{~J} / \mathrm{mole})\).
Problem 268
If the vapor pressure of \(\mathrm{CC} 1_{4}\) (carbon tetrachloride) is \(.132\) atm at \(23^{\circ} \mathrm{C}\) and \(.526 \mathrm{~atm}\) at \(58^{\circ} \mathrm{C}\), what is the \(\Delta \mathrm{H}^{\prime}\) in this temperature range?
Problem 269
A sugar solution was prepared by dissolving \(9.0 \mathrm{~g}\) of sugar in \(500 \mathrm{~g}\) of water. At \(27^{\circ} \mathrm{C}\), the osmotic pressure was measured as \(2.46\) atm. Determine the molecular weight of the sugar.
Problem 270
A chemist dissolves \(10 \mathrm{~g}\) of an unknown protein in a liter of water at \(25^{\circ} \mathrm{C}\). The osmotic pressure is found to be \(9.25\) \(\mathrm{mmHg}\). What is the protein's molecular weight. Based upon the number of moles in \(10 \mathrm{~g}\) of protein, what would the freezing point depression and boiling point elevation be? Assume \(\mathrm{R}=\) Universal Gas Constant \(=.0821\) (liter\(\left.\mathrm{atm} / \mathrm{mole}^{\circ} \mathrm{K}\right), \mathrm{k}_{\mathrm{f}}=\left(1.86^{\circ} \mathrm{C} / \mathrm{m}\right)\), and \(\mathrm{k}_{\mathrm{b}}=\left(.52^{\circ} \mathrm{C} / \mathrm{m}\right)\)
Problem 528
A solution of \(20.0 \mathrm{~g}\) of a non-volatile solute in \(100 \mathrm{~g}\) of benzene at \(30^{\circ} \mathrm{C}\) has a vapor pressure \(13.4\) torr lower than the vapor pressure of pure benzene. What is the mole fraction of solute? Vapor pressure of benzene at \(30^{\circ} \mathrm{C}=\) \(121.8\) torr.
