1. CH. 23 TRANSITION ELEMENTS RECALL 1. characteristics of alkai & alkaline metals 2. Hund’s Rule 3. e - notation; elements / ions 4. why transition element? 5. Lewis acid-base 6. Magnetism 1. Alkali: shiny, soft, low melting / boiling pt, react w / H 2 O, not found natural state, low IE, ns 1, strong red agents, very soluble salts Alkaline: shiny, silvery, higher melt / boil pts, not found natural state, less react than 1A, ns 2,higher IE, strong red agents, lower solubility 2. e - enters orbital 1 at a time till orbital half filled w/ same spin, then pair w/ opposite spin 4. occupied “d” orbital e - in neutral state 5. donate-accept e - pair 6. dia & para magnetic

2. Fe, Co, Ni, Cu, Ag some most familiar & imprt trans elements Numerous chem properties, consider: general aspects ox #’s Jet Engine 38% Ti 6 % Co 0.022 Ta 37% Ni 5% Al 12% Cr 1% No

3. OXIDATION STATES Common ox state in soln not same ox state in solid Mn +2 (aq) MnO 4 - (aq) MnO 2 (s) Organometallic Cmpds: metal in low + state or - state Exotic Cmpds: in ox state not shown 1. more than 1 stable ox state 2. colored cmpds 3. magnetic properties 1. loss outer s e - first 2. loss additional d e - Existence of d e - contribute to characteristics

4. Ex. MnO 4 -2 is stable in strong basic soln. In acidic soln, reacts to form permanganate and MnO 2 (s). Wrtie balanced overall rxn from the two half-rxns.

5. IONS IN AQUEOUS SOLUTION 1 st Series 1. Except Cu neg std electrode potential (red) for +2 state 2. Act as Lewis acid to H 2 O molecules form metal complex w / other ion / molecules present Co(H 2 O) 6 +3 (aq) E o = 1.95 V Co(NH 3 ) 6 +3 (aq) E o = 0.10 V more stable as Co +3 (aq) 3. L to R, red potential increase L to R lower ox state, incr eff nuclear charge 4. Same trend for 2nd & 3rd series ReO 4 -2 (MnO 4 - ) Cd +2 (Zn +2 ) crude comparisons, many diff chem properties

6. Ex. Write balance eqn of CuS in 3M HNO 3. Cu (s) + H + (aq) + NO 3 -1 (aq) -----> Cu +2 (aq) + S (s) + NO (g) + H 2 O (l)

7. TREND OF OXIDES 1. For specific element, highest ox state act as ox agent Sc 2 O 3 & TiO 2 not good CrO 3 & Mn 2 O 7 good 2. Low states, basic high state, acidic in soln in H 2 O FeO (insol in H 2 O or base), disolve in acidic soln, thus, exhibits basic characteristics 3. Shift ionic to covalent behavior in Met-O bond as metal ox # increases, attraction for e - on “O” incr MnO ionic Mn 2 O 7 polar covalent

8. OXIDES -- PAINT PIGMENTS NOT chem  when exposed to sunlight / air *color due from incomplete filled d-shell *depend on particular metal & ox state Co: orange - purple - green - violet Ni: blue - greenish

9. Ferromagnetism: overlap of atomic orbitals most common: Fe, Co, Ni permanent magnets MAGNESTISM Para: unpaired e - in valence shell, d orbital drawn into magnetic field Dia: pair e -, repelled by magnetic field nd 0 or nd 10 DIA PARA FERRO no centers isolated centers coupled centers aligned