Inorganic Chemistry Answers

Answer ALL parts a) — d).

a) Give the FULL electronic configuration of potassium.

b) Draw the radial distribution functions (RDFs) for the 4s and 3d orbitals, and use them to explain your answer to part a).

c) Explain briefly why many homoleptic transition metal complexes of carbon monoxide, CO, tend to obey the eighteen-electron rule.

d) For the ligands listed below, identify those that are n-acids and/or n- bases.

Br-, CO, H2O, PMe3

1 . Answer ALL parts a) — c).
a) Use the principles of Valence Shell Electron Pair Repulsion (VSEPR) to predict the structures of the following species.

XeF2; [XeF3]+; XeF4

b) Some of the halogens form oxo-acids in which their oxidation state is +7. Comment briefly on the observations that:
i) fluorine does not form a compound of this type;
ii) the compounds of iodine (H5IO6) and chlOrine (HCIO4) have different structures.

2 。Draw the structure of the following coordination compounds and determine the oxidation state, da nt electronic configuration, ( t2 gm eg” Or emt2" configuration and the spin only magnetic moment of the metal atom.
i) [CO(H2O )6]2+
ii) [Fe(ox)s]3-, ox = oxalate dianion, C2O42-

iii) [Ni(en)3]2+ , en = 1,2-diaminoethane

6. Answer ALL parts a) — c).
a) Draw the structure of the following coordination compounds and determine the oxidation state, dn electronic configuration,t2gm egn or emt2n configuration and the spin only magnetic moment (Us.o.) of the metal ion.

i. [Co(NH3)6]2+

ii. [Cu(en)3]2+, en = 1,2-diaminoethane
iii. [NiCl4]2-
B)Use the Bohr model of the hydrogen atom to explain atomic emission spectra. Your answer should include appropriate diagrams.

1.Rank the lead halide salts in order of their solubility in water?
2.Which is more soluble in water, NaIO3 or CSIO3?
3. Rank the group 2 Carbonates in order of thermal stability ?

Which of the following molecules exhibit rotational and or vibrational spectra
H2, HF, CO, NO

5. a) Name the factors that affect the thermal stability of alkali metal salts. Explain the
stability trend observed in case of nitrates of these metals.
b) Why is the monomeric beryllium hydride unstable? Describe the structure of
polymeric beryllium hydride.

3. a) Give the names of any two alloys of aluminium which have some amount of copper or
magnesium. How are these more advantageous than pure aluminium?
b) Why boric acid is a very weak monobasic acid (pH = 9.25)? Explain with suitable
equation.
c) Why iron, cobalt and nickel do not form typical interstitial carbides? Write the type of
carbides they form.

10. a) Arrive at the Lewis structure of XeF4 using the steps given in Unit 3.
b) Predict the hybridization state of each carbon atom in allene which has the following
structure:
CH2 = C = CH2
c) Calculate the number of normal modes of vibration for the following compounds:
i) H2O
CH4
ii) HBr

a) Explain why [Ni(CN)4—]2- is square planar.


b) What is the chelate effect? What is the principal thermodynamic driving force behind the chelate effect?

A pink solid (1) has the empirical formula CoCI3.5NH3.H2O. An aqueous solution of 1 is also pink and rapidly precipitates three moles of AgCI on titration with a AgNO3 solution. When 1 is heated it loses 1 mol of H2O to give a purple solid (2) with the same Co:NH3:Cl ratio as 1. On titration with a AgNO3 solution, 2 precipitates 2 moles of AgCl. Deduce and draw the structures of the two octahedral complexes of Co, 1 and 2.

d) State the types of isomerism that may be exhibited by the following complex, [Cr(en)2(H2O)2] 3+, and draw the structure for each isomer

en = 1,2-diaminoethane.

a) There are three compounds (A, B & C) with the formula CrCl3.6H2O. A is violet in colour; when an aqueous solution of A is treated with
AgNO , 3 moles of AgCI per mole of A are produced; A doesn’t lose any water in a desiccator.

B is grey-green in colour; when an aqueous solution of B is treated with AgNO3, it produces 2 moles of AgCl per mole of B; one mole of B loses one mole of water when kept in a desiccator.

C is deep green in colour; when an aqueous solution of C is treated with AgNO3, 3 moles of AgCl per mole of C are produced; one mole of C loses two moles of water when kept in a desiccator.


Identify A, B and C and state what type of isomerism these compounds exhibit.




b) Draw the d-orbital splitting diagram for [Fe(CN)6]-2 and state whether it is

a high-spin or low-spin complex. How would you confirm this
experimentally?

) Draw the structure of [Ni(CN)4]2-, showing the stereochemistry. Use crystal field splitting arguments to explain your answer.