A useful solvent that will dissolve salts as well as organic compounds is the compound acetonitrile, H3CCN. It is present in paint strippers.(a) Write the Lewis structure for acetonitrile, and indicate the direction of the dipole moment in the molecule.(b) Identify the hybrid orbitals used by the carbon atoms in the molecule to form σ bonds.(c) Describe the atomic orbitals that form the π bonds in the molecule. Note that it is not necessary to hybridize the nitrogen atom.

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.

1. For each molecular geometry, give the number of total electron pairs, the number of bonding pairs and the number of lone pairs on the central atom. (a) (b) (c) 2. For the following species provide the Lewis structure and make a 3D sketch showing estimated bond angles. Determine the polarity of each molecular and draw the dipole. a) SF4 b) KrF4 3. Determine the 3D structure of the molecule of formula C2H4O (H3CCHO). Indicate the geometry around each "central" atom and estimate bond angles. Representing Molecular Geometries on Paper X-A-X XX Linear Trigonal planar Bent Tetrahedral Trigonal pyramidal Trigonal bipyramidal Seesaw Octahedral Square planar

1. Draw the Lewis structures for each of the following ions or molecules. For each, give (i) the molecular shape, (ii) the electron pair geometry at the central atom, and (iii) the hybridization of the central atom. (a) POF3 (b) XeO₂F3+ (c) BrCl₂ (d) N3 (the central atom is N; two other N's are bonded to it) (e) PF3