Answer to Question #62540 in Inorganic Chemistry for emmanuel

Question

1.List and give the electronic configurations of the 3d transition elements.

2.Explain briefly why CuSO4 is blue while ZnSO4 is white.

3.list and explain five patterns of reaction that occur in addition polymerisation.

4.list three application of solubility

Answer 1

1)
Sc: [Ar] 4s2 3d1
Ti: [Ar] 4s2 3d2
V: [Ar] 4s2 3d3
Cr: [Ar] 4s1 3d5
Mn:[Ar] 4s2 3d5
Fe: [Ar] 4s2 3d6
Co: [Ar] 4s2 3d7
Ni: [Ar] 4s2 3d8
Cu: [Ar] 4s1 3d10
Zn: [Ar] 4s2 3d10

2)
Copper(II) in CuSO4 has the following electronic configuration [Ar] 4s0 3d9, where d-electron can move within d-level. However, zink(II) in ZnSO4 has completely filled d-level [Ar] 4s0 3d10 with no possibility to move some electrons within that level. In turn, those transfers of the electrons within the d-level are making d-metal cations colored.

3)
a) nCH2=CH2 = [-CH2-CH2-]n (The conversion is highly exothermic. Coordination polymerization is the most pervasive technology, which means that metal chlorides or metal oxides are used. The most common catalysts consist of titanium(III) chloride, the so-called Ziegler-Natta catalysts. Another common catalyst is the Phillips catalyst, prepared by depositing chromium(VI) oxide on silica. Polyethylene can be produced through radical polymerization, but this route has only limited utility and typically requires high-pressure apparatus)
b) nCH3-CH=CH2 = [-CH(CH3)-CH2-]n (A Ziegler-Natta catalyst is able to restrict linking of monomer molecules to a specific regular orientation, either isotactic, when all methyl groups are positioned at the same side with respect to the backbone of the polymer chain, or syndiotactic, when the positions of the methyl groups alternate. Commercially available isotactic polypropylene is made with two types of Ziegler-Natta catalysts. The first group of the catalysts encompasses solid (mostly supported) catalysts and certain types of soluble metallocene catalysts. Such isotactic macromolecules coil into a helical shape; these helices then line up next to one another to form the crystals that give commercial isotactic polypropylene many of its desirable properties)
c) nCF2=CF2 = [-CF2-CF2-]n (Because PTFE is poorly soluble in almost all solvents, the polymerization is conducted as an emulsion in water. This process gives a suspension of polymer particles. Alternatively, the polymerization is conducted using a surfactant such as PFOS)
d) nCH2=CH(C6H5) = [-CH2-CH(C6H5)-]n (Polystyrene results when styrene monomers interconnect. In the polymerization, the carbon-carbon pi bond (in the vinyl group) is broken and a new carbon-carbon single (sigma) bond is formed, attaching another styrene monomer to the chain. The newly formed sigma bond is much stronger than the pi bond that was broken, thus it is very difficult to depolymerize polystyrene. About a few thousand monomers typically comprise a chain of polystyrene, giving a molecular weight of 100,000–400,000)
e) nCH2=CHCl = [-CH2-CHCl]n (Once the reaction has run its course, the resulting PVC slurry is degassed and stripped to remove excess VCM, which is recycled. The polymer is then passed through a centrifuge to remove water. The slurry is further dried in a hot air bed, and the resulting powder sieved before storage or pelletization. Normally, the resulting PVC has a VCM content of less than 1 part per million. Other production processes, such as micro-suspension polymerization and emulsion polymerization, produce PVC with smaller particle sizes (10 μm vs. 120–150 μm for suspension PVC) with slightly different properties and with somewhat different sets of applications)

4)
(i) In predicting the formation of a precipitate.
(ii) In predicting the solubility of sparingly soluble salts Knowing the solubility product of a sparingly soluble salt at any given temperature, we can predict its solubility.
(iii) Purification of common salt.
(iv) Salting out of soap.
(v) In qualitative analysis.
(vi) Calculation of remaining concentration after precipitation.
(vii) Calculation of simultaneous solubility.