Question

Please provide balanced half reactions for Chromium(III) AcetylAcetonate

Cr2O3 + 6 Hacac → 2 Cr(acac)3 + 3 H2O

Answer 1

Acetylacetone's official name is 2,4-pentanedione but us old guys like the sound of chromium acac. Formula: CH3C(O)CH2C(O)CH3 now you may recall that it is easy to pull a H+ of a diketone like this to give the anion where the 1-ve charge is delocalized over both O atoms in the anion. Let me try to draw: H3C-C(-Oδ-)-CH-C(-Oδ-)-CH3 (internal C-C bonds should also have dotted lines over them). Mr Wikipedia does a much better job of drawing it than I do. [1] acac- is a surperb chelate (bidentate) ligand (results in 6-membered ring). So we use the OH- in NH3(aq) to pull the H+ off acacH:
acacH +OH- → acac- + H2O
Can't use strong base otherwise Cr(OH)3 will ppt.
The acac- then readily cmplxs with the Cr(III):
[Cr(H2O)6]3+ + 3acac- → Cr(acac)3 + 6H2O