Question

A Question for your Report: The typical yields here are 70-80% for the Copper compound wi students getting as much as 90% yield. But the yield is typically only 30-35% for theCobalt compound with 40% about the best I've seen, we can account for maybe 1 spillage, product left on glassware, etc. etc. I've tried greatly increasing the amount of peroxide used and this doesn't have much effect. th some % yield loss due to handling, ie. The question is then-Why is the Cobalt compound synthetic yield so low? Check out your Coordination compounds chapter in the text for clues.

Answer 1

Cobalt compound synthetic yield is very low. The Co+ion can exist in stable state only if it is complexed. It is then not easily reduced. Coordination compounds will form by the Lewis acid base reaction of neutral molecules or anions (ligands) and central metal atom or ion by the coordinate covalent bond. The synthesis of Hexamminecobalt III Chloride, because of six ammonia the Cobalt gets six ligands. Ligands bond with central atom the coordination number is six which also dictates that it is an octahedral. According to crystal field model, the expected crystal field splitting energy or Δ。is high. This makes the six 3d electrons pair up on the lowest energy orbitals which makes cobalt very stable. Based on this, the colbalt is stable which means that it will not react as expected and the theoretical yield will be low.