A 1.37 M solution of citric acid (H3C6H5O7) in water has a density of 1.10 g/cm3. Calculate the mass percent, molality, mole fraction, and normality of the citric acid. Citric acid has three acidic protons.

6-111 As noted in Section 6-8C, the amount of external pressure that must be applied to a more concentrated solution to stop the passage of solvent molecules across a semipermeable membrane is known as the osmotic pressure The osmotic pressure obeys a law similar in form to the ideal gas law (discussed in Section 5-4), where Substituting for pressure and solving for osmotic pressures gives the following equation: RT MRT, where M is the concentration or molarity of the solution. (a) Determine the osmotic pressure at 25°C of a 0.0020 M sucrose (C12H22O11) solution. (b) Seawater contains 3.4 g of salts for every liter of solution. Assuming the solute consists entirely of NaCl (and complete dissociation of the NaCI salt), calculate the osmotic pressure of seawater at 25°C. (c) The average osmotic pressure of blood is 7.7 atm at 25°C. What concentration of glucose (C6H12O6) will be isotonic with blood? (d) Lysozyme is an enzyme that breaks bacterial cell walls. A solution containing 0.150 g of this enzyme in 210. mL of solution has an osmotic pressure of 0.953 torr at 25°C. What is the molar mass of lysozyme? (e) The osmotic pressure of an aqueous solution of a certain protein was measured in order to determine the protein's molar mass. The solution contained 3.50 mg of protein dissolved in sufficient water to form 5.00 mL of solution. The osmotic pressure of the solution at 25°C was found to be 1.54 torr. Calculate the molar mass of the protein.

Water at 25 C has a density of 0.997 g/cm3. Calculate the molality and molarity of pure water at this temperature.

Explain why solutions of HBr in benzene (a nonpolar solvent) are nonconductive, while solutions in water (a polar solvent) are conductive.

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

The freezing point of 0.109 m aqueous formic acid is 0.210C. Formic acid, HCHO2, is partially dissociated according to the equation HCHO2(aq)H+(aq)+CHO2(aq) Calculate the percentage of HCHO2 molecules that are dissociated, assuming the equation for the freezing-point depression holds for the total concentration of molecules and ions in the solution.

For each of the following pairs of solutions, select the solution for which solute solubility is greatest. a. Oxygen gas in water with P = 1 atm and T = 10C Oxygen gas in water with P = 1 atm and T = 20C b. Nitrogen gas in water with P = 2 atm and T = 50C Nitrogen gas in water with P = 1 atm and T = 70C c. Table salt in water with P = 1 atm and T = 40C Table salt in water with P = 1 atm and T = 70C d. Table sugar in water with P = 3 atm and T = 30C Table sugar in water with P = 1 atm and T = 80C

Concentrated hydrochloric acid contains 1.00 mol HCl dissolved in 3.31 mol H2O. What is the mole fraction of HCl in concentrated hydrochloric acid? What is the molal concentration of HCl?

Fructose, C6H12O6, is a sugar occurring in honey and fruits. The sweetest sugar, it is nearly twice as sweet as sucrose (cane or beet sugar). How much water should be added to 1.75 g of fructose to give a 0.125 m solution?

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.)