Chemistry 115

Quiz 6

 

May 24, 2001

 

Name __________________________

Multiple Choice: Place the letter corresponding to the best answer in front of each of the following.

(6)

_C__ 1. For the complex ion, Fe(H2O)62+, the species acting as a Lewis base is

A. Fe(H2O)62+ B. Fe2+ C. H2O D. none of these

H2O donates an electron pair to form the bond with the Fe2+

_C__ 2. The oxidation state of nickel in the complex ion [Ni(CN)4I]3- is

A. –3 B. –2 C. +2 D. +5

Ni + [-5](-1 for each of four CN- + -1 for the I-) = -3(charge on ion); Ni = -3 + 5 = +2

_B__ 3. The ligand that can act as a bidenate species that forms a chelate ring is

A. Cl B. en = H2NCH2CH2NH2 C. H2O D. SCN-

The two nitrogens can each donate an electron pair and form a chelate ring with the metal ion.

_D__ 4. The coordination number of gold in the complex ion [Au(dien)Cl3]2- is

A. 3 B. 4 C. 5 D. 6

The dien ligand has three N's that will occupy coordination sites around the Au

_B__ 5. The type of isomerism that the complex ion [Co(CN)5(SCN)]3- might be expected to show is

A. geometric B. linkage C. optical D. None of these

SCN- is an ambidentate, monodentate ligand that can bind through either the S or the N

_A__ 6. The number of stereoisomers expected for the tetrahedral ion [CdCl2(H2O)2] is

A. 1 B. 2 C. 3 D. 4

The tetrahedral arrangement cannot give rise to geometric isomers and 4 different ligands are required to make the mirror images of a tetrahedral arrangement non-superimposable.

7. Name the following coordination compounds. (4)

  1. Na3 [AlF6] sodium hexafluoroaluminate(III)

B. [Co(NH3)5Br] SO4 pentaamminebromocobalt(III) sulfate

  1. [Co(NH3)5SO4] Br pentaamminesulfatocobalt(III) bromide
  2. [Fe(H2O)2(en)2] Cl2 diaquabis(ethylenediamine)iron(II) chloride

 

8. Write the appropriate chemical formulas for each of the following species. (4)

  1. tetraaquadihydroxoaluminum(III) chloride [Al(OH)2(H2O)4] Cl
  2. tetraamminecarbonatocobalt(III) sulfate [Co(CO3)(NH3)4]2 SO4
  3. potassium tetraiodomercurate(II) K2 [HgI4]
  4. hexaamminenickel(II) tris(oxalato)chromate(III) [Ni(NH3)6]3 [Cr(C2O4)3]2

 

9. For the complex ion [Co(Cl)2( en)2]+ (6)

  1. Sketch the three steroisomers
  1. Classify each steroisomer as cis or trans
  2. Identify the enantiomeric pair.

 

 

Cl

 

+

 

 

 

N

 

+

 

 

 

N

 

+

 

 

|

 

 

 

 

/

|

 

 

 

 

 

|

\

 

N

 

|

 

N

 

N

 

|

 

Cl

|

Cl

 

|

 

N

 

\

 

/

 

 

 

\

 

/

 

|

 

\

 

/

 

|

 

Co

 

|

 

 

 

Co

 

 

|

 

 

Co

 

 

 

/

 

\

 

 

 

/

 

\

 

|

 

/

 

\

 

N

 

|

 

N

 

N

 

|

 

Cl

|

Cl

 

|

 

N

 

 

|

 

 

 

 

\

|

 

 

 

 

 

|

/

 

 

 

Cl

 

 

 

 

 

N

 

 

 

 

 

N

 

 

trans

cis

cis

 

 

enantiomers