Determining polar or non polar: 4.27

[Michele Shi 1K]

Can someone explain the process on how to determine if these molecules are polar or non polar? The molecules in the problem are C5H5N, C2H6,CHCL3

[Christine Wastila 1H]

Look for sizable differences in electronegativity. For example, C-H bonds do not cause partial charges because there is not a large difference in electronegativity between C and H. However, a C-N bond or a C-Cl bond could cause polarity because N and Cl are more electronegative than C, causing a partial negative charge on those atoms and a partial positive charge on the C. Also, look at the structure to make sure the dipoles do not cancel. Therefore, C5H5N and CHCl3 are polar and C2H6 is nonpolar.

[Aliza Ajmal 1D]

Also, it's also important to note that a molecule can still have polar bonds and end up being nonpolar if the dipole moments cancel. Simply put: nonpolar molecules have no net dipole moments. Dipole moments cancel out due to symmetry. For example, if the molecule has a symmetrical shape like a tetrahedral shape then the dipole moments will cancel.