378. mg of an unknown protein are dissolved in enough solvent to make 5.00 mL of solution. The osmotic pressure of this solution is measured to be 0.104 atm at 25.0 °C. Calculate the molar mass of the protein. Be sure your answer has the correct number of significant digits. show work. don't use Ai ?

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?

The solubility of lead nitrate at 100C is 140.0 g/100 g water. A solution at 100C consists of 57.0 g of lead nitrate in 64.0 g of water. When the solution is cooled 10C to 25.0 g of lead nitrate crystallize out. What is the solubility of lead nitrate in g/100 g water at 10C?

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.

Instead of using NaCl to melt the ice on your sidewalk you decide to use CaCl2. If you add 35.0 g of CaCl2 to 150. g of water, what is the freezing point of the solution? (Assume i = 2.7 for CaCl2.)

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.)

Samples of each of the substances listed below are dissolved in 125 g of water. Which of the solutions has the highest boiling point? (a) 3.0 g sucrose, C12H22O11 (b) 1.0 g glycerol, C3H3(OH)3 (c) 1.0 g propylene glycol, C3H6(OH)2 (d) 2.0 g glucose, C6H12(OH)2

What mass of a 4.00% NaOH solution by mass contains 15.0 g of NaOH?

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.

Cooking A cook prepares a solution for boiling by adding12.5 g of NaCl to a pot holding 0.750 L of water. Atwhat temperature should the solution in the pot boil?Use Table 14.5 for needed data.