CHE 112  Answers for Complex Ion Practice

1) F, is 6. Remember oxalate is a bidentate.

2) T

3) T, absorb high frequency, which is short wavelength.

4) F, is 4--Cl's are outside the coordination sphere

5) T--it has lost its one 4s electron. The remaining 3d electrons are all paired.

6) F, subscript 2 after ammonia ligands should be 3.               

7) T                 8)   F, zinc hexachloroplatinate(IV),  -ate suffix because complex ion is an anion.

9) Cr(CN)₆^4- ; the cation is Cr²⁺, its electron configuration is 3d⁴. CN^- is a strong field ligand. It causes such a large splitting that Hund's Rule is not obeyed, so all 4 electrons are in the lower 3d set.

10) 260 kJ/mole  (Remember, h is per atom, & you need Avagadro's Number.)

11) 5.9 x 10^-9 M.   Do the modified ICE chart. At equilibirum, silver ion concentration is x, ammonia concentration is 0.458 + 2x, and the complex ion concentration is 0.0210 - x.

12) 8.5 x 10⁴   Verify that K = (K_sp )( K_f)