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CHAPTER 15:

1. Water molecules are hydrogen bonded to each other but not to air molecules. Net attraction is inward minimizing the water surface area. Hydrogen bonding makes it more difficult for water molecules to escape from the liquid phase to the vapor phase.
2. Ice has a honeycomb like structure of hydrogen bonded water molecules.
3. Surfactants lower the surface tension of water by interfering with hydrogen bonding.
4. The surface tension of liquids tends to hold a drop of liquid in a spherical shape; gravity tends to flatten the drop.
5. Water bonding has intermolecular hydrogen bonding between its molecules; methane does not.
6. the dissolving medium is the solvent and the dissolved particles are the solute.
7. As individual solute ions break away form the crystal, the negatively and positively charged ions become surrounded by solvent molecules and the ionic crystal dissolves.
8. Because they dissociate into ions.
9. In writing the formula of a hydrate, a dot is used to connect the formula of the compound with the number of water molecules per formula unit.
10. A. insoluble, non polar
    1. soluble, ionic
    2. insoluble, nonpolar
    3. soluble, ionic
    4. soluble, polar
11. Water is the solvent; acetic acid is the solute
12. Efflorescent compounds such as certain hydrates loose water to the air. Hydroscopic compunds remove water from the air, sometimnes forming hydrates.
13. 51.2% water
14. the particles of a suspension are much larger and do not stay suspended infinitely.
15. Colloids have particles smaller than those in suspensions and larger than those in solutions.
16. The particles in a suspension will settle over time.
17. Particles in a colloid such as gelatin are smaller than the holes in filter paper and cannot be filtered out.
18. A beam of light is visible as it passes through a colloid; a beam of light is invisible as it passes through a solution.
19. Browmain motion is caused by the collisions of the molecules of a dispersion medium witth the small dispersed colloidal particles. Flashes of light, or scintillations, are seen when collloids are studied under a microscope. Colloids scintillate because the particles reflecting and scattering the light move erraticly. The particles in a collision are too small to be seen under a microscope and do not cause scintillations.

CHAPTER 16

1. Chemical composition of the solute and solvent; agitation, temperature and size of the solute.
2. Grans of solute per 100g of solvent
3. Temperature and pressure if the solute is a gas
4. a. Add solvent
   1. increase the pressure
5. 1.4g/L
6. if the number of moles and the volume of a solution is known then its molarity is determined by dividing the moles of solute by the volume of the solution.
7. diluting a solution reduces the number of moles of solute per unit of volume, but the total number of moles of solute in the solvent does not change.
8. Express the concentration as the ratio of trhe volume of solute to the volume of the solution (v/v) or as the ratio of the mass of the solute to the mass of the solution (m/m)
9. 6.27 x 10^-1 MCuSO4
10. 1.00 x 10^-2 mol KNO3
11. 7.50 mL
12. 2% (v/v) diethyl ether
13. 7.5 x 10^1 g K2SO4