Lecture 82/2/07 Seminar Monday

QUIZ 2 1. Write the complete ionic and net ionic equation for: AgNO 3 + NaI ⇄ AgI + NaNO 3 2. The solubility of Ag 2 CrO 4 (331.8 g/mol) in water is 2.7 x g/L. Calculate the K sp of silver chromate.

Le Chatelier’s review Given the following reaction: NH 4 HS (s) ⇄ NH 3 (g) + H 2 S (g)  H = + Which direction will the reaction shift if you: a. Add more NH 4 HS b. Remove NH 3 c. Decrease the temperature

A chemistry student mixes 20.0 mL of 4.5 x M AgNO 3 with 10.0 mL of 7.5 x M of NaBrO 3. Will a precipitate of AgBrO 3 form? K sp (AgBrO 3 ) = 6.7 x 10 -5

K sp (AgCl) = 1.8 x If you have solution that is 1.0 x M Ag +, what is the minimum Cl - concentration for a precipitate to form?

Separations Using the solubility rules, how could you separate the following ion pairs? 1. Na + and Ba Pb 2+ and Ca 2+

Solubility Rules Soluble CompoundsExceptions NO 3 - None C 2 H 3 O 2 - (acetate)None Cl -, Br -, I - Compounds with Ag +, Hg 2 2+, Pb 2+ SO 4 2- Compounds with Sr 2+, Ba 2+, Hg 2 2+, Pb 2+ Group 1A and NH 4 + None Insoluble CompoundsExceptions S 2- Group 1A and NH 4 + [Ca 2+, Sr 2+, Ba 2+ ] CO 3 2-,PO 4 3-, C 2 O 4 2-, CrO 4 2- Group 1A and NH 4 + OH - Group 1A and NH 4 + [Ca 2+, Sr 2+, Ba 2+ ]

Cu 2+ and Ag + are found together in aqueous solution. Using the table of solubility product constants devise a way to separate these ions by adding one reagent to precipitate one of them as an insoluble salt and leave the other in solution. Cu +, Cu 2+ CuBr 6.3 x CuI 1.3 x Cu(OH) x CuSCN 6.3 x Ag + AgBr 5.4 x AgBrO x AgCH 3 CO x AgCN 6.0 x Ag 2 CO x Ag 2 C 2 O x AgCl 1.8 x Ag 2 CrO x AgI 8.5 x AgSCN 1.0 x Ag 2 SO x 10 -5