Dinitrogen difluoride, N₂F₂, is the only stable, simple inor-ganic molecule with an N=N bond. The compound occurs incisand transforms.(a) Draw the molecular shapes of the two forms of N₂F₂.(b) Predict the polarity, if any, of each form.

The molecule shown here is difluoromethane (CH2F2), which isused as a refrigerant called R-32. (a) Based on the structure, howmany electron domains surround the C atom in this molecule?(b) Would the molecule have a nonzero dipole moment? (c) Ifthe molecule is polar, which of the following describes the directionof the overall dipole moment vector in the molecule:(i) from the carbon atom toward a fluorine atom, (ii) from thecarbon atom to a point midway between the fluorine atoms,(iii) from the carbon atom to a point midway between the hydrogenatoms, or (iv) from the carbon atom toward a hydrogenatom?

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.

For each statement, indicate whether it is true or false. (a) Inorder to make a covalent bond, the orbitals on each atom inthe bond must overlap. (b) A p orbital on one atom cannotmake a bond to an s orbital on another atom. (c) Lone pairsof electrons on an atom in a molecule influence the shape ofa molecule. (d) The 1s orbital has a nodal plane. (e) The 2porbital has a nodal plane.