The folloving chemicals have been disslved in the same amount of water- issolved in the a) 1.5 mol of Fe(NO3)3(s); b) 2.1 mol of Cu(NO3)2(s); c) 6.0 mol of sucrose, C1H2011(s) d) 2.9 mol of NaCI(s). Circle all solutions below that will have the same new freezing point temperature. (Assume complete dissolution to ions for all ionic chemicals). Support your answer with the appropriate calculations Solution: a) b) c) d)

(a) If you dissolve 10.0 g (about one heaping teaspoonful) of sugar (sucrose, C12H22O11) in a cup of water (250. g), what are the mole fraction, molality, and weight percent of sugar? (b) Seawater has a sodium ion concentration of 1.08 104 ppm. If the sodium is present in the form of dissolved sodium chloride, what mass of NaCl is in each liter of seawater? Seawater is denser than pure water because of dissolved salts. Its density is 1.05 g/mL

In Exercise 96 in Chapter 8, the pressure of CO2 in a bottle of sparkling wine was calculated assuming that the CO2 was insoluble in water. This was a bad assumption. Redo this problem by assuming that CO2 obeys Henry s law. Use the data given in that problem to calculate the partial pressure of CO2 in the gas phase and the solubility of CO2 in the wine at 25C. The Henrys law constant for CO2 is 3.1 w2 mol/L atm at 25C with Henrys law in the form C = kP, where C is the concentration of the gas in mol/L.

The Henry's law constant for the solubility of helium gas in water is 3.8104M/atm at 25C. (a) Express the constant for the solubility of helium gas in M/mm Hg. (b) If the partial pressure of He at 25C is 293 mm Hg, what is the concentration of dissolved He in mol/L at 25C? (c) What volume of helium gas can be dissolved in 10.00 L of water at 293 mm Hg and 25C? (Ignore the partial pressure of water.)

Consider two solutions at a certain temperature. Solution X has a nonelectrolyte as a solute and an osmotic pressure of 1.8 atm. Solution Y also has a nonelectrolyte as a solute and an osmotic pressure of 4.2 atm. What is the osmotic pressure of a solution made up of equal volumes of solutions X and Y at the same temperature? Assume that the volumes are additive.

Sodium chloride (NaCl) is commonly used to melt ice on roads during the winter. Calcium chloride (CaCl2) is sometimes used for this purpose too. Let us compare the effectiveness of equal masses of these two compounds in lowering the freezing point of water, by calculating the freezing point depression of solutions containing 200. g of each salt in 1.00 kg of water. (An advantage of CaCl2 is that it acts more quickly because it is hygroscopic, that is. it absorbs moisture from the air to give a solution and begin the process. A disadvantage is that this compound is more costly.)

Calculate the freezing point of 525 g of water that contains 25.0 g of NaCl. Assume i, the vant Hoff factor, is 1.85 for NaCl.