2. Could NH4Cl or NaCl be used to precipitate Group I cations? Explain.

3. In the confirmatory test for lead, both sulfuric acid and potassium chromate are used separately to identify lead. Which reagent is more sensitive? By how much? Ksp for lead sulfate = 1.3 x 10-8 ,Ksp for lead chromate = 2 x 10-16

4. Why are the confirmatory tests for sodium and ammonium ion performed on the original sample, rather than the group IV solution separated from groups I, II and III?

5. The solubility of Pb(OH)2 is listed in the CRC as 0.155 gm/L. What is the solubility product constant, Ksp? MWt of Pb(OH)2 = 241.2

6. What is the pH of a solution saturated with Pb(OH)2?

7. What is the maximum molar lead ion concentration that can exist in a solution saturated with H2S at pH = 1.00? Saturated H2S =[H2S] = 0.10 M,
K1 for H2S = 1 x 10-7, K2 for H2S = 1 x 10-19, Ksp for PbS = 3 x 10-28

8. Calcium phosphate, Ca3(PO4)2, commonly called superphosphate, is used as a slow release phosphate fertilizer. How many liters of water are required to dissolve 1.0 gm of superphosphate if the Ksp = 1.2 x 10-19 , MWt = 310.2

9. A zinc ion, Zn+2, forms a complex with four molecules of ammonia, NH3. Write the equilibrium for which the instability constant, Kinst, of this complex is defined.

10. Most metals precipitate as hydroxides in the presence of a strong base. Zinc ion forms a soluble complex with hydroxide ions. What is the term used to describe this unusual solubility of a metal in base? What other metals also do this?

11. Colloids exhibit the Tyndall effect and Brownian motion, not seen in true solutions. Describe the visual appearance and molecular origins of these effects.

12. What is meant by the terms diamagnetic, paramagnetic and ferromagnetic?
How would I determine which class a given material belongs in experimentally?

Extra credit (5 pt)-(Use back of page-a rough sketch might aid your setup)
If I took a cube measuring 1 cm on a side and completely carved it into perfect colloidal sized cubes each 0.1 µm on a side, how much total surface area in m2, would now be present? 1 cm = 10-2 m, 1 µm = 10-6 m
Area of any cube = 6 x (side)2