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1.40 a) CBr₄ has polar bonds but its geometry is tetrahedral so the bond dipoles cancel. Therefore, the molecule has no dipole moment and is nonpolar. b) NH₃ has polar bonds and a pyramidal geometry, so it has a dipole moment. It is a polar molecule. c) The C-O bonds of are polar and the geometry is bent at the so it has a dipole H + moment. It is a polar molecule. d) The C-CI bonds of are polar and its C-N H geometry is tetrahedral. The bond dipoles do not H cancel so it has a dipole moment and is a polar molecule. e) The C-O bonds of CO₂ are polar but it has a linear geometry, so the bond dipoles cancel. It has no dipole moment and is a nonpolar molecule. 1.41 a) C-1 has two single bonds and one double bond, so it H has trigonal planar geometry. C-2 has two double C C bonds, so it has linear geometry. 1 2 H b) The C has four bonds, so it has tetrahedral geometry. N-1 has a single bond, a double bond, + and an unshared pair, so it has bent (trigonal H N=N=N: planar) geometry. N-2 has two double bonds, so it C 1 2 3 has linear geometry. There is a resonance structure for this molecule that has two unshared pairs on HH N-1, a single bond between N-1 and N-2, a triple bond between N-2 and N-3, and only one unshared pair on N-3. The formal charges are -1 on N-1, +1 on N-2, and 0 on N-3. c) The sulfur has a single bond, a double bond, and an unshared pair, + + S S so it has bent (trigonal planar) : geometry. Resonance makes both O: S-O bonds identical. d) The C has four single bonds, so it has tetrahedral H Cl geometry. The N has two single bonds and a double C C X bond, so it has trigonal planar geometry. H H 11