Mini Project- d-block Chemistry

Question 1.
a)  Complete the following table that gives the electronic configuration of the 1st row d-block elements andtheir corresponding ions in oxidations states (II) and (III).
Atomic no.    Element    Symbol    M(0)    M(II)    M(III)
21    Scandium    Sc    [Ar]4s23d1    [Ar] 3d1    [Ar]
22
23
24
25
26
27
28
29
30

b)What are the two irregularities in placing electrons in  the3d orbitals of the elements given above and why are such irregularities allowed

Question 2.
a) Give a definition of a Lewis acid and a Lewis base.
b) In a reaction of CoCl3 and NH3 a number of cobalt (III) complexes withdifferent colour were formed. Explain this observation.

c)Draw the structure of each of the possible complexes formed in part (b).

d) Draw the structure of the complex [Cr(en)3]Cl3

Question 3.

Complete the following table
Metal complex    Coordination number     Oxidation state of the metal
[Co(NH3)5(ONO)]2+
[Cu(NH3)4]2+
[Fe(CN)6]3
[Ni(CO)4]
NA4[Mn(ox)3]
[Vo(acac)2]

Question 4.
Give the chemical formula of the following metal complexes:
a)    Potassium hexafluorocobaltate (III)
b)    Tetraamminechloronitrocobalt(III) chloride
c)    Tris(ethylenediamine)nickel(II) sulfate
d)    Tris(ethylenediamine)cobalt(II) nitrate
e)    Cobalt(II) hexanitrocobaltate(III)
f)    Ammineaquadicarbonyldicyanoiron(III)
Question 5.
Name the following complexes:
a)    [CoI(NH3)5]Cl2
b)    [Cu(NH3)4]SO4
c)    [CrCl(en)2(H2O)]Cl2
d)    K3[Fe(ox)(ONO)4]
e)    [Sc(NC)2(NO)4]+
f)    [Co(NCS)3(SCN)3]3-
Question 6.
For each of the following complexes, draw and name the possible types of isomers that may arise.
a)    diaquadiiodoplatinum(II)
b)    trioxalatoiron(3-)
c)    dichlorotetraammineiron(+)
d)    triamminetrichloroiron(III)

Question 7.
a) On clearly labelled three dimensional Cartesian axes give ONE clear diagram of the boundary surfaces used to represent the angular part of the egset of 3d-orbitals (the ‘ring’of the dz2 orbital may be omitted for clarity; this must be stated) for Mn+.

b)Indicate the sites of an octahedral set of fluoro ligands in [MF6]n+.

c) Give a clear energy level diagram to show the effect that an octahedral set of fluoro ligands will have on the energies of the egand t2g sets of 3d-orbitals relative to those in an isolated metal ion.

Question 8.
Draw up a table for isolated ions (M2+) of the ten elements of the First Transition Series, using the column headings:

M2+    Electronic configuration    No. of unpaired electrons    Magnetic moment /BM

Question 9.
Using ‘box notation’ give the d-electron configuration of each of the following ions in(a) a weak crystal fieldand (b) a strong crystal field.  In each case give the value of µ (spin only), and the Crystal Field Stabilisation Energy (CFSE) in terms of Dq (i.e. oct) and P (the pairing energy).
(i) Cr2+(ii) Cr3+(iii) Fe2+ (iv) Fe3+(v) Ni3+
Question 10.
a) What is the order of increasing crystal field strength of the ligands H2O, ethylenediamine and SCN-deduced from their positions in the spectrochemical series?

b) How can the uv-visible spectra of [Ni(Et2en)2Cl2] and [Ni(Et2en)2(SCN)2] be used to explain the difference in colour of these two complexes?

c) The coordination geometries around the nickel atom in the nominally six-coordinate complexes [Ni(Et2en)2X2] (X = Cl-, SCN-, NO3-and I-) range fromslightly axially distorted octahedral to virtually square planar. What are the likely structures for these complexes based on their magnetic