SI – Chem 178Worksheet 1

Leader: Kyle

Chapter 13 Sections 1-5

1. What are the three kinds of interactions involved in solution formation?

a.

b.

c.

2. Which are endothermic and which are exothermic? Why?

3. When we open a bottle of carbonated soft drink, bubbles of carbon dioxide gas escape. Explain why using Henry’s Law.

4. Calculate the mass percentage, molarity, and molality of a solution containing 2.4g of K2SO4 in 40g of water.

5. A solution is formed by dissolving 9.0g of KCl in 600.0g of water.

a. What is the vapor pressure of the solution at 25 ⁰C if the vapor pressure of pure H2O is 23.8 torr at 25 ⁰C?

b. What is the boiling-point elevation? (Kb=0.52⁰C/m)

c. What is the freezing-point depression? (Kf=1.86⁰C/m)

d. What is the osmotic pressure of the solution? (Assume the volume of the solution is 0.600L)

6. Two solutions of sugar with concentrations of 0.2M and 0.5M are separated by a semipermeable membrane. The 0.2M solution is labeled A and the other is labeled B. During Osmosis:

a. Sugar molecules move from solution A to B.

b. Water molecules move from solution A to B.

c. Sugar molecules move from solution B to A.

d. Water molecules move from solution B to A.

e. Osmosis does not occur.

Chapter 15 Sections 1-3

1. Write the equilibrium constant expressions Kp and Kc for the following reversible reactions:

a. H2(g) + I2(g)<=>2HI(g)

b. 2Cl2(g) +2H2O(g)<=>4HCl(g)+O2(g)

c. (CH3)4Sn (s) <=> (CH3)4Sn (g)

2. N2O2 and NO2 have the following equilibrium equation:

2 NO2 (g) <=> N2O4 (g)

A closed container held at 298K is filled with N2O4 at a partial pressure of 0.51atm and NO2 at a partial pressure of 0.56atm. At equilibrium the partial pressure of N2O4 is measured to be 0.54atm. What is the value of the equilibrium constant?