2nd Quarter Chemistry 2012: Polarity of Molecules

Polarity Worksheet

For each of the following pairs of molecules, determine which is most polar and explain your reason for making this choice:

1)        carbon disulfide                   OR                  sulfur difluoride

2)        nitrogen trichloride              OR                  oxygen dichloride

3)        boron trihydride                    OR                  ammonia

4)        chlorine                                 OR                  phosphorus trichloride

5)        silicon dioxide                      OR                  carbon dioxide

6)        CH₄                             OR                  CH₂Cl₂

7)        silicon tetrabromide                        OR                  HCN

8)        nitrogen trifluoride               OR                  phosphorus trifluoride

SPOILER ALERT!!!    SPOILER ALERT!!!    SPOILER ALERT!!!    SPOILER ALERT!!!

ANSWERS: 

1)        carbon disulfide                   OR                  sulfur difluoride

         carbon disulfide is nonpolar

2)        nitrogen trichloride              OR                  oxygen dichloride

            both are polar, but oxygen dichloride is less symmetric than nitrogen trichloride, making it more polar.

3)        boron trihydride                  OR                  ammonia

         boron trihydride is nonpolar.

4)        chlorine                                 OR                  phosphorus trichloride

            chlorine is nonpolar

5)        silicon dioxide                      OR                  carbon dioxide

         It’s a tie, because both are nonpolar

6)        CH₄                             OR                  CH₂Cl₂

            CH₄ is nonpolar

7)        silicon tetrabromide                        OR                  HCN

         silicon tetrabromide is nonpolar

8)        nitrogen trifluoride               OR                  phosphorus trifluoride

            Both are polar and equally symmetric, but the difference in electronegativity between N-F is less than that between P-F