# Essays

755 Words4 Pages
Chapter 13 Homework Problems

Notes: 1.) Hand in your answers/work on a separate sheet (not a printout of these problems). 2.) You can receive partial credit even if your answer is incorrect, but only if you show your work! 3.) Be sure to include units (amu, g, mL, etc.) on any answers that need them. This is worth points! 4.) Be sure to use the correct number of significant figures in your answers. This is worth points too!

1. Tell what kinds of intermolecular forces could occur between the following pairs of solute and solvent, and place the list in order from weakest to strongest solute-solvent attraction. Some pairs may experience more than one type of force.

a. water
363 g of a 1.85 m solution of CS2 dissolved in acetone, C3H6O d. 675 g of an aqueous solution that is 9.48% Ca(NO3)2 by mass

6. Suppose we make a solution by mixing water and ethylene glycol (C2H6O2, the main ingredient in antifreeze).

a. Calculate the vapor pressure of water above a solution made by combining 90.0 g of water and 90.0 g of ethylene glycol at 383.15 K. The vapor pressure of pure water can be found in Appendix B. b. What mass of ethylene glycol would we have to add to 1.00 L of water in order to reduce its vapor pressure to 32.0 mmHg at 55.0˚C?

7. Use data from Table 13.4 to calculate the freezing and boiling points of the following solutions.

a. An aqueous solution of 0.625 m sucrose b. A solution of C6H14 dissolved in benzene that is 10.0% C6H14 by mass c. 5.00 g of PI3 dissolved in 485 g of ethanol d. 10.0 g (NH4)2SO4 and 6.00 g of KCl in 50.0 g of water

8. Every liter of seawater contains 3.40 g of various salts. Suppose all the salt is NaCl (not actually true). What would be the osmotic pressure of seawater at 25˚C?

9. Glucose is about 0.100% of blood serum by mass. In the problems below, you can assume that the rest is water.

a. Calculate the glucose concentration in ppm. b. Calculate the mole fraction of glucose. c. Calculate the molality of glucose. d. You’d need more information to