The partial molar volumes of two liquids A and B in a mixture are 128 cm³.mol™ and 132 cm³.mol¯" respectively. In the mixture, the mole fraction of A is 0.6. The molar masses of the A and Bare 241.1 g.mol™ and 198.2 g. mol™ respectively.

Fluoridation of city water supplies has been practiced in the United States for several decades. It is done by continuously adding sodium fluoride to water as it comes from a reservoir. Assume you live in a medium-sized city of 150,000 people and that 660 L (170 gal) of water is used per person per day. What mass of sodium fluoride (in kilograms) must be added to the water supply each year (365 days) to have the required fluoride concentration of 1 ppm (part per million)that is, 1 kilogram of fluoride per 1 million kilograms of water? (Sodium fluoride is 45.0% fluoride, and water has a density of 1.00 g/cm3.)

The dispersed phase of a certain colloidal dispersion consists of spheres of diameter 1.0 102 nm. (a) What are the volume (V=43r2) and surface area (A = r2) of each sphere? (b) How many spheres are required to give a total volume of 1.0 cm3? What is the total surface area of these spheres in square meters?

For each of the following pairs of solutions, select the solution for which solute solubility is greatest. a. Ammonia gas in water with P = 1 atm and T = 50C Ammonia gas in water with P = 1 atm and T = 90C b. Carbon dioxide gas in water with P = 2 atm and T = 50C Carbon dioxide gas in water with P = 1 atm and T = 50C c. Table salt in water with P = 1 atm and T = 60C Table salt in water with P = 1 atm and T = 50C d. Table sugar in water with P = 2 atm and T = 40C Table sugar in water with P = 1 atm and T = 70C