Is acetone a polar or nonpolar substance?
Acetone (chemical formula `CH_3COCH_3` ) exhibits the properties of both the polar as well as nonpolar substances. For example, it mixes in both water (`H_2O` ) and carbon tetrachloride (`C Cl_4` ). Water is a polar molecule, while carbon tetrachloride is a nonpolar molecule. If we use the 'like dissolves like' concept, then acetone is both polar and nonpolar.
This dual character of acetone is due to its ability to make hydrogen bonds with water and the presence of two methyl groups. The former makes it polar, while the latter means that it can dissolve nonpolar substances such as carbon tetrachloride.
A polar compound is one where the two charges, positive and negative, are separated by some distance and this separation is measured by dipole moment. Acetone has a dipole moment of 2.88 D and hence is a polar molecule (despite possessing characteristics of both the polar and nonpolar substances).
Hope this helps.