what is the molality of a solution containing 0.75 moles of sodium hydroxide in 500 mL of water at 25 degrees celsius? The density of water at 25 degrees celsius is 1 g/ml.

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?

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.

Starch contains CC, CH, CO, and OH bonds. Hydrocarbons have only CC and CH bonds. Both starch and hydrocarbons can form colloidal dispersions in water. Which dispersion is classified as hydrophobic? Which is hydrophilic? Explain briefly.

In a mountainous location, the boiling point of pure water is found to be 95C. How many grams of sodium chloride must be added to 1 kg of water to bring the boiling point back to 100C? Assume that i = 2.

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?

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?

Assume that 30 L of maple sap yields one kilogram of maple syrup (66% sucrose, C12H22O11). What is the molality of the sucrose solution after one fourth of the water content of the sap has been removed?

If you prepared a saturated aqueous solution of potassiumchloride at 25°C and then heated it to 50°C, wouldyou describe the solution as unsaturated, saturated, orsupersaturated? Explain.

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.