Chapter 22

The \(\left[\mathrm{Co}(\mathrm{en})_{3}\right]^{3+}\) ion has a maximum absorption at \(470 \mathrm{~nm}\). What color do you expect for this ion?

The \(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right]^{3+}\) ion has a yellow color, but when one \(\mathrm{NH}_{3}\) ligand is replaced by \(\mathrm{H}_{2} \mathrm{O}\) to give \(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5}\left(\mathrm{H}_{2} \mathrm{O}\right)\right]^{3+}\) the color shifts to red. Is this shift in the expected direction? Explain.

The \(\left[\mathrm{Co}(\mathrm{en})_{3}\right]^{3+}\) ion has a yellow color, but the \(\left[\mathrm{CoF}_{6}\right]^{3-}\) ion has a blue color. Is the shift from yellow to blue expected when ethylenediamine ligands are replaced by \(\mathrm{F}^{-}\) ligands? Explain.

What is the value of \(\Delta\) (in \(\mathrm{kJ} / \mathrm{mol}\) ) when \(\lambda=500 \mathrm{~nm}\), corresponding to an electron jump between \(d\) -orbital levels in a complex with \(d^{1}\) configuration?

What is the value of \(\Delta\) (in \(\mathrm{kJ} / \mathrm{mol}\) ) when \(\lambda=680 \mathrm{~nm}\), corresponding to an electron jump between \(d\) -orbital levels in a complex with \(d^{1}\) configuration?

The hexaaquascandium(III) ion, \(\left[\mathrm{Sc}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}\), is colorless. Explain why this might be expected.

The tetraaquazinc(II) ion, \(\left[\mathrm{Zn}\left(\mathrm{H}_{2} \mathrm{O}\right)_{4}\right]^{2+}\), is colorless. Explain why this might be expected.

There are only two geometric isomers of the triamminetrichloroplatinum(IV) ion, \(\left[\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{2} \mathrm{Cl}_{3}\right]^{+}\). How many geometric isomers would be expected for this ion if it had a regular planar hexagonal geometry? Give drawings for them. Does this rule out a planar hexagonal geometry for \(\left[\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{2} \mathrm{Cl}_{4}\right]^{+} ?\) Explain.

Find the concentrations of \(\mathrm{Ag}^{+}(a q), \mathrm{NH}_{3}(a q)\), and \(\left[\mathrm{Ag}\left(\mathrm{NH}_{3}\right)_{2}\right]^{+}(a q)\) at equilibrium when \(0.10 \mathrm{~mol} \mathrm{Ag}^{+}(a q)\) and \(0.10 \mathrm{~mol} \mathrm{NH}_{3}(a q)\) are made up to \(1.00 \mathrm{~L}\) of solution. The dissociation constant, \(K_{d}\), for the complex \(\left[\mathrm{Ag}\left(\mathrm{NH}_{3}\right)_{2}\right]^{+}\) is \(5.9 \times 10^{-8}\).

Describe the functions of hemoglobin and myoglobin in the body. What is similar and what is different about the two functions?

Describe the mechanism of the cooperative release of oxygen from oxyhemoglobin.

Consider the complex ion \(\left[\mathrm{CoCO}_{3}\left(\mathrm{NH}_{3}\right)_{4}\right]^{+}\), where the \(\mathrm{CO}_{3}^{2-}\) is a bidentate ligand. a. Is this complex ion octahedral or square planar? b. What is the oxidation state of the cobalt?

Does the complex ion \(\left[\mathrm{Co}(\mathrm{en})_{2} \mathrm{Cl}_{2}\right]^{+}\) have cis-trans geometric isomers?

Draw each of the following to determine if they have optical isomers? a. \(\operatorname{Ir}(\mathrm{en})_{3}^{3+}\) b. \(\left[\operatorname{Ir}\left(\mathrm{H}_{2} \mathrm{O}\right)_{3} \mathrm{Cl}_{3}\right]\)

Is it possible for a square planar complex to have optical isomers?

The complex \(\left[\mathrm{Fe}(\mathrm{en})_{2} \mathrm{Cl}_{2}\right] \mathrm{Cl}\) is low spin. a. What is the geometry of the complex ion? b. What is the oxidation state of the Fe? c. Are there geometric isomers, and is the compound optically active?

Consider the complex ion \(\left[\mathrm{CoF}_{6}\right]^{3-}\). a. What is the geometry? b. Which is a more likely color for this ion to absorb, red or blue? c. Would you expect this complex to be high or low spin?

What is the name of \(\mathrm{K}_{2}[\mathrm{MoOCl}]_{4}\) ?

Write the formula and draw the structure of \(c i s\) -tetraamminedichlorocobalt(III).

You are studying an octahedral transition metal complex that contains the \(\mathrm{Co}^{2+}\) ion and discover that it has a strong absorption in the blue region of the visible spectrum. Would you suspect (not conclude) that this complex is high spin or low spin. Explain?

Consider the low-spin complex ions \(\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}\) and \(\left[\mathrm{Mn}(\mathrm{CN})_{6}\right]^{4-}\) a. Name them. b. Determine the number of unpaired electrons. c. Indicate which complex ion would absorb the highestfrequency light.