5. (a) (b) The complex ion NiC14² has two unpaired electrons, whereas Ni(CN)4² is diamagnetic. Propose structures for these two complex ions (square-planar or tetrahedral). Draw the crystal field diagrams of two complex ions.

The complex ion Fe(CN)6³ is paramagnetic with one unpaired electron. The complex ion Fe(SCN)6³ has five unpaired electrons. Draw the crystal field diagrams of two complex ions. Which compound absorbs light with the shorter wavelength? Where does SCN- lie in the spectrochemical series relative to CN-? (hint: stronger or weaker 4. (a) (b) (c) field)

a) Consider the following two cobalt complexes: [Co(H2O)2(OH)4] Complex A [Co(CO)6] 3+ Complex B (i) Draw the d-electron configuration for A and B. Label each set of orbitals. (ii) Explain how the d-electron configuration changes when cobalt is replaced by iridium in A and B. (iii) Calculate the CFSE for A and B. Show all calculations and units. (iv) Which of these two complexes (A or B) will interact with a magnet? Motivate your answer.

Balance this equation and balanced reaction equation and the quantities included in the procedure to calculate the theoretical yield of K[Cr(C2O4)2(H2O)2]·2H2O.

Which of these complex ions is expected to be diamagnetic?           (B) [Co(CN)6]3–          (A) [CoCl6] 3–          (C) [CoF6]3–          (D) All the above

A) Using a cobalt (III) ion as the central metal atom, and with chloride ions (Cl-) and ammonia (NH3) molecules as the ligands, draw both isomers of the coordination complex that will exhibit fac/mer isomerism. B) Using a platinum (II) ion as the central metal atom, with chloride ions and ammonia molecules as the ligands, draw both isomers of the coordination complex that will exhibit cis/trans isomerism. Platinum (II) forms four coordinate bonds.

b) Draw the structure of each of the following complexes. Clearly show the stereocentre of central metal ion. Where multiple geometric isomers are possible, draw both. (i) [Fe(SCN)4(H2O)2]²- (ii) [Co(en)2Cl2]CI (iii) [Ni(NH3)4(C2O4)2]. H2O