(b) The carbon-carbon bond length of coordinated ethylene in Pt(PPh3)2(1²-C2H4), F, is 1.44 Å, as determined by X-ray crystal structure analysis. The carbon-carbon bond length of free (uncoordinated) ethylene is 1.34 Å. Rationalise this difference in bond length. Sketch relevant molecular orbitals.

In the series of group 5A hydrides, of general formulaMH3, the measured bond distances are P¬H, 1.419 Å;As¬H, 1.519 Å; Sb¬H, 1.707 Å. (a) Compare these valueswith those estimated by use of the atomic radii inFigure 7.7. (b) Explain the steady increase in M¬H bonddistance in this series in terms of the electron configurationsof the M atoms.

(a) Construct a molecular orbital energy diagram of N₂. (b) Use this diagram to explain why the first ionization of N₂ is greater than that of N. (b) Use this diagram to predict which is more favorable: the first electron affinity of N₂ or that of N.

(a) What are trihalomethanes (THMs)? (b) Draw the Lewisstructures of two example THMs.

What is the molecular geometry of the PF4^+ (15P & 9F). Explain your answer briefly

Write the Lewis structure for each of the following species,and indicate the structure of each: (a) SeO32 - ; (b) S2Cl2;(c) chlorosulfonic acid, HSO3Cl (chlorine is bonded tosulfur).

Predict the magnetic properties and bond orders of (a) theperoxide ion, O22 - ; (b) the acetylide ion, C22 - .

The sulfate ion can be represented with four S—O bonds orwith two S—O and two S=O bonds. (a) Which representation is better from the stand point of formal charges? (b) What is theshape of the sulfate ion, and what hybrid orbitals of S are postu-lated for the σ bonding? (c) In view of the answer to part (b),what orbitals of S must be used for the π bonds? What orbitalsof O? (d) Draw a diagram to show how one atomic orbital fromS and one from O overlap to form a π bond.

(a) Complete the Lewis structure for the molecule below. How many lone pairs are there? HHH H-Ca Cb C-N=C=S H (b) For the structure shown, give the hybridizations of the following atoms: (i) Ca (i) Ca-Cb-C (ii) Cb (iii) N (ii) H-Ca-C b (c) Give approximate values of the bond angles for the following: (iv) S (iii) C-N-C

(a) Predict the geometry of the SbCl52- ion, using theVSEPR method.(b) The ion SbCl63- is prepared from SbCl52-by treatment with Cl2. Determine the steric number of thecentral antimony atom in this ion, and discuss theextension of the VSEPR theory that would be neededfor the prediction of its molecular geometry.