PS5.1. Describe all the energy changes which must be considered in the solution process. Indicate the types of interactions which are important in the solution process and discuss what conditions favor and do not favor formation of a solution.

PS5.2. Which substance of each of the following pairs is likely to be more soluble in water? Explain each choice and, for the substance of each pair that is less soluble in water, suggest a better solvent. Include Lewis structures for each of the substances. (NOTE: If you have vitamins as an option you do not have to draw the structure of vitamin E.)

a) nitrogen(g) and ammonia(g)
b) methylamine(g) and carbon disulfide(l)
c) vitamin B6(s) or vitamin E(s) NOTE: See page 565 in your textbook.

d) phenol(s) or toluene(l)

PS5.3. Describe the attractive forces present when NaCl(s), NH3(g) and methanol(l) dissolve in water. Use the space below to sketch diagrams depicting at the atomic level how each of the three substances interact with water molecules.

Drawing:


Drawing:
Drawing:
Explanation:
Explanation:
Explanation:


PS5.5. A concentrated solution of sucrose, C12H22O11, contains 185.6 g dissolved in 316.02 g water. The density of the solution is 1.1507 g mL-1 Calculate;

a) the weight percent C12H22O11 in the solution;


b) the mol fraction of C12H22O11 in the solution;

c) molality of C12H22O11 in the solution;

d) the molarity of C12H22O11 in the solution


PS5.6. Describe how you would prepare the following aqueous solutions;

a) 100 mL of a 0.399 M Mg(NO3)2 solution

b) 527 g of a 36.93 % (by weight) solution of NaOH.

c) 410.6 g (grams of solution) of a 2.26 molal NaCl solution

PS5.7. An aqueous solution of sulfuric acid is 1.26 molal and has a density of 1.6864 g mL-1. Calculate the

a) weight percent sulfuric acid;

b) mol fraction of sulfuric acid;

c) the molarity of sulfuric acid.

PS5.8. A solution of glycerol, C3H8O3, in water is prepared by mixing 345.1 g C3H8O3 with 1749 g of water. The molarity was found to be 1.846 M. Calculate

a) the molality of the glycerol solution
b) the density of the glycerol solution

PS5.9. A solution of a compound called potassium acid phthlate, is prepared by dissolving 2.43 g in 250 mLs of water. This solution is then reacted with exactly 14.39 mLs of a 0.827 M NaOH solution. Assume KHP reacts in a one-to-one ratio with NaOH, calculate the molar mass of KHP (potassium acid phthlate).