[Free ligand] (mM) [Bound ligand] (mM) 0.6 2 1.5 4 3.0 6. 6.0 8 15.0 10

a. In the absorption spectrum of the complex ion Cr(NCS)63, there is a band corresponding to the absorption of a photon of light with an energy of 1.75 104 cm-1. Given 1 cm1 = 1.986 1023 J, what is the wavelength of this photon? b. The CrNC bond angle in Cr(NCS)63 is predicted to be 180. What is the hybridization of the N atom in the Ncs- ligand when a Lewis acid-base reaction occurs between Cr3+ and NCs- that would give a 180 CrNC bond angle? Cr(NCS)63 undergoes substitution by ethylenediamine (en) according to the equation Cr(NCS)63+2enCr(NCS)2(en)2++4NCS Does Cr(NCS)2(en)2+ exhibit geometric isomerism? Does Cr(NCS)2(en)2+ exhibit optical isomerism?

Trimethylphosphine, P(CH3)3, can act as a ligand by donating the lone pair of electrons on the phosphorus atom. If trimethylphosphine is added to a solution of nickel(Il) chloride in acetone, a blue compound that has a molecular mass of approximately 270 g and contains 21.5% Ni, 26.0% Cl, and 52.5% P(CH3)3 can be isolated. This blue compound does not have any isomeric forms. What are the geometry and molecular formula of the blue compound?

What is the coordination number of the central metal atom in the following complexes? (a) [Fe(H2O)63+] (b) [Pt(NH3)Br3] (c) [V(en)Cl42] (d) [Au(CN)2+]