1. Lecture 294/13/05

2. Counting electrons 96,500 C/mol e-

3. 1.50 amps flow through a Ag + (aq) solution for 15.0 min. What mass of Ag metal is deposited? (1.5 amps) x (15.0 min) x (60 s/min) 1350 C ÷ 96,500 C/mol e- 0.014 mole e - s Ag + + e -  Ag (s) x 1 mol Ag(s) 1 mole e - 0.014 mole Ag x 107.9 g/mol 1.5 g Ag

4. The anode reaction in a lead storage battery is: Pb(s) + HSO 4 - (aq)  PbSO 4 (s) + H + (aq) + 2e- If a battery delivers 1.50 amp, and you have 454 g of Pb, how long will the battery last? 454 g Pb 2.19 mol Pb ÷ 207 g/mol 4.38 mole e - s x 2 mol e - 1 mole Pb 423000 C ÷ 1.5 amps 282,000 s  78.3 hours x 96,500 C/mol e-

5. END OF MATERIAL FOR EXAM 3

6. Coordination complexes Central metal Ligands Complexing agents Molecules or ions bound to metal Anions or polar molecules with unshared e - pair # of ligands bound to metal = coordination # Complex ions - [Ag(CN) 2 ] - or [Ni(H 2 O) 6 ] 2+ Charge on ion = sum of metal + ligand charges Coordination complexes - [Ni(H 2 O) 6 ]Cl 2 Salt with complex ion

8. Coordination complexes Complex formation can change physical and chemical properties Ag + (aq) + e -  Ag (s) E° = 0.799 V [Ag(CN) 2 ] - + e-  Ag (s) + 2CN - (aq)E° = - 0.31 V

9. Monodentate H 2 O, NH 3, CN - polydentate (chelating agent)

13. Naming complex compounds 1. Name of cation is given before the name of the anion 2. With a complex ion, ligands named before the metal 1. If more than one ligand, name alphabetically 3. Anionic ligands end in “o”, neutral ones bear the name of the molecule 4. Greek prefixes (di-, tri-, tetra-, penta-) used for number of ligands 5. If complex ion is an anion, name ends in “ate” 6. Oxidation # of metal is given in paranthesis in roman numerals

14. Naming complex compounds Ligands NH 3 Amine COCarbonyl H 2 O Aqua Br - Bromo CO 3 2- carbonato Cl - Chloro CN - cyano F - Fluoro OH - hydroxo C 2 O 4 2- oxalato NCS - isothiocyanato SCN - thiocyanato H 2 NCH 2 CH 2 NH 2 ethylenediamine (en)