CHE 112 Complex Ion Practice
Answers are available by a hyperlink after the last problem. You may use paper, pencil, calculator, Periodic Table, Tables of Equilibrium Constants, the Spectrochemical Series, Table of Electron Configurations of Elements, & your handwritten notes on Complex Ion Nomenclature.
Answer the questions 1 - 8 as TRUE or FALSE:
1) The coordination number of ferric ion in Fe(H2O)4(C2O4)+ is 5.
2) In the octahedral complexes of Mo2+ with weak field ligands, there are 4 unpaired electrons.
3) In general, the complexes involving strong field ligands tend to absorb short wavelength visible light.
4) In [Pt(NH3)4]Cl4 platinum has a coordination number of 8.
5) Cuprous ion, Cu+ , has no unpaired electrons.
6) The formula for ammonium pentachlorohydroxoferrate(III) is (NH4)2FeCl5(OH).
7) The formula for diamminetriaquahydroxochromium(III) nitrate is
[Cr(NH3)2(H2O)3(OH)](NO3)2
.
8) The name of Zn[PtCl6] is zinc hexachloroplatinum(IV).
9) Consider the complex ions Cr(H2O)62+ and Cr(CN)64- . Both of these ions are paramagnetic, but one of them is less paramagnetic than the other. Use crystal field theory and the Spectrochemical Series to decide which of these complexes is the less paramagnetic.
10) The 460 nm absorption in MnF62- corresponds to its crystal-field splitting energy. Calculate this energy in kJ/mole.
11) If 0.500 mole of NH3 gas is added to 1.00 L of 0.0210 M AgNO3 (aq), what will the free silver ion concentration be at equilibrium? Assume that the volume does not change. (Hint: First write the equation for the formation of the relevant complex ion.)
12) Calculate the value of K for the equilibrium
AgI(s) + 2CN-(aq) == Ag(CN)2-(aq) + I-(aq)
(Hint: Use the values of Ksp for AgI and Kf for Ag(CN)2-)