Problem 234
Assuming that the density of water is \(.9971\left(\mathrm{~g} / \mathrm{cm}^{3}\right)\) at \(25^{\circ} \mathrm{C}\) and that of ice at \(0^{\circ}\) is \(917\left(\mathrm{~g} / \mathrm{cm}^{3}\right)\), what percent of a water jug at \(25^{\circ} \mathrm{C}\) should be left empty so that, if the water freezes, it will just fill the jug?
Problem 235
The molecular diameter of an N2 mplecule, as deduced from the Van der Waals b parameter, is \(3.15 \times 10 " 8 \mathrm{~cm}\). The density of liquid nitrogen is \(0.8081 \mathrm{~g} / \mathrm{cm} 3 .\) On a hard- sphere model, what fraction of the liquid volume appears to be empty space?
Problem 236
The freezing point constant of toluene is \(3.33^{\circ} \mathrm{C}\) per mole per \(1000 \mathrm{~g}\). Calculate the freezing point of a solution prepared by dissolving \(0.4\) mole of solute in \(500 \mathrm{~g}\) of toluene. The freezing point of toluene is \(-95.0^{\circ} \mathrm{C}\).
Problem 237
By how much will 50 grams of water have its freezing point depressed if you add 30 grams (molecular weight 80 ) of glucose to it?
Problem 240
The molal freezing point constant for a certain liquid is \(0.500^{\circ} \mathrm{C} .26 .4 \mathrm{~g}\) of a solute dissolved in \(250 \mathrm{~g}\) of this liquid yields a solution which has a freezing point \(0.125^{\circ}\) below that of the pure liquid. Calculate the molecular weight of this solute.
Problem 241
Liquid naphthalene normally freezes at \(80.2^{\circ} \mathrm{C}\). When 1 mole of solute is dissolved in \(1000 \mathrm{~g}\) of naphthalene, the freezing point of the solution is \(73.2^{\circ} \mathrm{C}\). When \(6.0 \mathrm{~g}\) of sulfur is dissolved in \(250 \mathrm{~g}\) of naphthalene, the freezing point is \(79.5^{\circ} \mathrm{C}\). What is the molecular weight of sulfur?
Problem 242
A chemist wishes to determine the molecular weight and molecular formula of fructose (a sugar). He places \(.946 \mathrm{~g}\) of it in \(150 \mathrm{~g}\) of \(\mathrm{H}_{2} \mathrm{O}\) (water) and finds that the freezing point of water is depressed to \(-0.0651^{\circ} \mathrm{C} .\) Determine the molecular weight and formula of fructose, assuming that the simplest formula of fructose is \(\left(\mathrm{CH}_{2}\right) \mathrm{O}\).
Problem 244
Calculate the approximate freezing point of a solution of \(162 \mathrm{~g}\) of \(\mathrm{HBr}\) in \(500 \mathrm{~g} \mathrm{H}_{2} \mathrm{O}\), assuming that the acid is \(90 \%\) Ionized.
Problem 245
What percent of the AB particles are dissociated by water if the freezing point of \(a(.0100 \mathrm{~m})\) AB solution is \(-0.0193^{\circ} \mathrm{C}\) ? The freezing point lowering constant of water is \(\left(-1.86^{\circ} \mathrm{C} / \mathrm{mole}\right)\)
Problem 246
What is the approximate boiling point at standard pressure of a solution prepared by dissolving \(234 \mathrm{~g}\) of \(\mathrm{NaCl}\) in \(500 \mathrm{~g}\) of \(\mathrm{H}_{2} \mathrm{O} ?\)
