determine the properties of colloid and their importance in the biological system.

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.

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

Refer to Figure 13.10 ( Sec. 13-4b) to answer these questions. (a) Does a saturated solution occur when 65.0 g LiCl is present in 100 g H2O at 40 C? Explain your answer. (b) Consider a solution that contains 95.0 g LiCl in 100 g H2O at 40 C. Is the solution unsaturated, saturated, or supersaturated? Explain your answer. (c) Consider a solution that contains 50. g Li2SO4 in 200. g H2O at 50 C. Is this solution unsaturated, saturated, or supersaturated? Explain your answer. Figure 13.10 Solubility of ionic compounds versus temperature.

6-20 Give a familiar example of solutions of each of these types: (a) Liquid in liquid (b) Solid in liquid (c) Gas in liquid (d) Gas in gas

The freezing point of a 0.21 m aqueous solution of H2SO4 is -0.796C. (a) What is i? (b) Is the solution made up primarily of (i) H2SO4 molecules only? (ii) H+ and HSO4- ions? (iii) 2H+ and 1SO42- ions?

Mixtures of gases are always true solutions. True or false? Explain why.

Calculate the molality of a solution made by dissolving 115.0 g ethylene glycol, HOCH2CH2OH, in 500. mL water. The density of water at this temperature is 0.978 g/mL. Calculate the molarity of the solution.

The following diagrams show varying amounts of the same solute (the red spheres) in varying amounts of solution. a. In which of the diagrams is the solution concentration the largest? b. In which two of the diagrams are the solution concentrations the same?

Refer to Figure 13.10 ( Sec. 13-4b) to determine whether these situations would result in an unsaturated, saturated, or supersaturated solution. 120. g RbCl is added to 100. g H2O at 50 °C. 30. g KCl is dissolved in 100. g H2O at 70 °C. 20. g NaCl is dissolved in 50. g H2O at 60 °C. Figure 13.10 Solubility of ionic compounds versus temperature.