POLARITY OF MOLECULES

1. POLARITY OF MOLECULES Molecules can also be described as either polar or nonpolar. When the individual dipole moments associated with each bond in the molecule cancel out due to symmetry or if no dipole moment exist, the molecule can be classified as a nonpolar molecule. Nonpolar molecules have no overall dipole moment. Otherwise, if an overall dipole moment exist, the molecule is polar.

2. p. 380

3. p. 380

4. p. 380

5. p. 380

6. Fig. 13-10, p. 379

7. Fig. 13-11, p. 380

8. Practice Problems 1. Draw the VSEPR sketch for each of the following showing the polarity of each bond. Describe each molecule as either polar or nonpolar. a) PH3 b) CH2O c) NO2- d) CBr4 e) C2H6 I) O2 2. Why would NH3 have a larger dipole moment than NF3? Trigonal planar, polar Trigonal pyramidal, polar bent, polar linear, nonpolar Tetrahedral, nonpolar Trigonal planar, nonpolar Ammonia has a trigonal pyramidal geometry with the dipoles along each N-H bond pointing inwards to the N-atom & the overall dipole is in one direction up through the lone pair of electrons of N. NF3 has the dipoles pointing outward to each F-atom and out to the lone pair of electrons thus each dipole counteracts the other reducing the overall effect.

9. Group Study Problems 1. Draw the VSEPR sketch for each of the following showing the polarity of each bond. Describe each molecule as either polar or nonpolar. a) H2S b) H3PO4 c) CF4 d) CH2FCl e) C2H2 f) O3 2. Why would CF2H2 have a larger dipole moment than CCl2F2?