Arkansas State University Department of Chemistry and Physics

Note: Only the questions have been listed to save space.

1. Draw a typical solubility plot. Label all parts including where saturated, unsaturated and supersaturated solutions would be on the plot. (10 points)

2. Describe positive deviation from Raoult's Law in terms of intermolecular forces. (6 points)

3. Explain why gases are less soluble at higher temperatures when liquids and solids are generally more soluble at higher temperatures. (4 points)

4. Explain how adding a nonvolatile solute always lowers the vapor pressure. (6 points) Be brief.

5. Define colligative property and give two examples. (4 points)

6. Draw a plot of energy vs. reaction coordinates for the making of a solution from two liquids showing exothermic mixing. (6 points)

7. Write the equilibrium expression for each of the following: Where possible, express both K _c and K _p. (6 points)
 
 

a)                                 Ni (s)+ 4 CO (g)		Ni(CO) 4 (g)
b)                              CH 4 (g) + Cl 2 (g)		HCl (g) + CH 3Cl (g)

8. For equation 7b, would K _c = K _p? Explain. (4 points)

9. Given the reaction below:
 

H 2 (g) + I 2 (g)

2 HI (g)

If Q = 25.4 and K_c = 54.3 at 430^oC, is the reaction at equilibrium? If not, which way will the reaction proceed? (4 points)

10. Determine the equilibrium concentrations for each species in the equation:
 

N 2 (g) + O 2 (g)

2 NO (g)

if the initial concentrations of N ₂ and O ₂ are 1.0 M and K _c = 0.020 at 2870^oC.(8 points)

11. According to Le Chatelier's Principle,

a) what effect would the addition of H ⁺ have on the equilibrium below? (4 points)
 
 

2 CrO 42 - (aq) + 2 H +(aq)

Cr2O 7 2 - (aq) + H 2O

b) what effect would the addition of OH ^- have on the equilibrium in part a) if the OH ^-reacts with H ⁺ to give water? (4 points)
 

12. Complete the equilibrium and write the Ksp expression for each of the following: (8 points)
 

a) PbCl 2 (s)
b) FeS (s)

13. Determine the molar solubility of CuS. K _sp = 6.0 x 10 ^{- 3 7} (6 points)

14. Determine the K _sp for PbI ₂ if the molar solubility is 1.52 x 10 ^{- 3} M. (6 points)

15. Calculate the solubility (g/L) of AgI in 0.24 M AgNO₃. K _sp = 8.3 x 10 ^{- 1 7} (8 points)

16. Tell if the following compounds are soluble (S) or insoluble (I) (6 points)
 

Fe(OH) 3 _______	CoClO 3 _______
Li2S _______	(NH 4) 2CrO 4 _______
NaI _______	BaSO 4________