The solid anhydrous solid CoCl2 is blue in color. Because it readily absorbs water from the air, it is used as a humidity indicator to monitor if equipment (such as a cell phone) has been exposed to excessive levels of moisture.Predict what product is formed by this reaction, and how many unpaired electrons this complex will have.

Transition metal complexes are highly likely to be colored because of a) the size of the energy gap within the d orbitals and the number of electrons. In ruby, the red color of ruby is attributed to a small amount of Cr³* substituting into Al2O3 which is made up of shared AIO, octahedra. Provide a hypothesis for the origin of the red color observed in ruby. Red pigments tend to be rare. If you had to design a new material that b) had an approximate bandgap that would absorb green, what ideas do you need to employ to find a new semiconductor that does not contain Cd, Hg or Pb as one of the components (see last lecture for ideas).

Which ligand formula and name combination is correct? A NH3, ammonia B C D III E I-, iodino CN-, cyanide SCN, sulfur cyanide Br, bromo

Answer the following questions about the complex ion [Co(en)₂Br₂]CI, where en = ethylenediamine. Name the metal in this complex a. b. C. d. e. f. g. What is the oxidation state of this metal? What is the coordination number of this metal? Which ligand is bidentate? What is the counter ion? What is the systematic name for this compound dibromobis(ethylenediamine)cobalt(III) chloride What is the significance of the square brackets Please answer all parts of the question. bromoethylenediaminecobalt(III) chloride chlorobromoethylenediaminecobalt(III) chloride dibromobis(ethylenediamine)cobalt(III) chloride chlorobis(ethylenediamine)cobalt(III) dibromide