The polarity of these compounds depends on the presence of polar C-O, C=O, OH, NH and CN bonds. The compounds which are most polar are capable of forming hydrogen bonds (see #4) and have NH or OH bonds. Although all of these compounds are polar, the degree of polarity ranges from slightly polar to highly polar. This is due to the effect of the size of the carbon chain on polarity and whether or not the compound can form hydrogen bonds.
3. The presence of halogen atoms, even though their electronegativities are relatively high, does not alter the polarity of an organic compound in a significant way. Therefore, these compounds are only slightly polar. The polarities of these compounds are more similar to hydrocarbons, which are nonpolar, than to water which is highly polar.