The vapor pressure of ethanol is 54.68 mm Hg at 25°C. How many grams of testosterone, C19H28O2, a nonvolatile, nonelectrolyte (MW = 288.4 g/mol), must be added to 267.4 grams of ethanol to reduce the vapor pressure to 53.77 mm Hg ? ethanol = CH3CH2OH = 46.07 g/mol.  ??g testosterone

What is the freezing point and normal boiling point of a solution made by adding 39 mL of acetone, C3H6O, to 225 mL of water? The densities of acetone and water are 0.790 g/cm3 and 1.00 g/cm3, respectively.

Insulin is a hormone responsible for the regulation of glucose levels in the blood. An aqueous solution of insulin has an osmotic pressure of 2.5 mm Hg at 25C. It is prepared by dissolving 0.100 g of insulin in enough water to make 125 mL of solution. What is the molar mass of insulin?

Two samples of sodium chloride solutions are brought to a boil on a stove. One of the solutions boils at 100.10C and the other at 100.15C. a Which of the solutions is more concentrated? b Which of the solutions would have a lower freezing point? c If you split the solution that boils at 100.1C into two portions, how would the boiling points of the samples compare? Which of the following statements do you agree with regarding the determination of your answer for part c? I. The question cannot be answered with certainty without knowing the volumes of each portion. II. Making the necessary assumption that the two samples have equal volumes, I was able to correctly answer the question. III. The volumes that the sample was split into are irrelevant when determining the correct answer.

Consider two hypothetical pure substances, AB(s) and XY(s). When equal molar amounts of these substances are placed in separate 500-mL samples of water, they undergo the following reactions: AB(s)A+(aq)+B(aq)XY(s)XY(aq) a Which solution would you expect to have the lower boiling point? Why? b Would you expect the vapor pressures of the two solutions to be equal? If not, which one would you expect to have the higher vapor pressure? c Describe a procedure that would make the two solutions have the same boiling point. d If you took 250 mL of the AB(aq) solution prepared above, would it have the same boiling point as the original solution? Be sure to explain your answer. e The container of XY(aq) is left out on the bench top for several days, which allows some of the water to evaporate from the solution. How would the melting point of this solution compare to the melting point of the original solution?

Will red blood cells crenate, hemolyze, or remain unaffected when placed in each of the solutions in Problem 8-102?

How many grams of the following nonelectrolytes would have to be mixed with 100.0 g of p-dichlorobenzene to increase the boiling point by 3.0C? To decrease the freezing point by 2.0C? (Use Table 10.2.) (a) succinic acid (C4H6O4) (b) caffeine (C8H10N4O2)

a. Use the following data to calculate the enthalpy of hydration for calcium chloride and calcium iodide. Lattice Energy Hsoln CaCl2(s) 2247kj/mol 46kj/mol Cal2(s) 2059kj/mol 104kj/mol b. Based on your answers to part a, which ion, Cl or I, is more strongly attracted to water?

When KNO3 is dissolved in water, the resulting solution is significantly colder than the water was originally. (a) Is the dissolution of KNO3 an endothermic or an exothermic process? (b) What conclusions can you draw about the intermolecular attractions involved in the process? (c) Is the resulting solution an ideal solution?

Calculate the molality of each of the following solutions: (a) 583 g of H2SO4 in 1.50 kg of water—the acid solution used in an automobile battery (b) 0.86 g of NaCI in 1.00102 g of water—a solution of sodium chloride for intravenous injection (c) 46.85 g of codeine, C18H21NO3, in 125.5 g of ethanol, C2H5OH (d) 25 g of I2 in 125 g of ethanol, C2H5OH