Is Acetone Polar or Nonpolar?

Answer: Acetone is a polar molecule due to the existence of a very electronegative oxygen (3.44) in the center of the molecule. This oxygen pulls electrons from the central carbon and other R- groups with lower electronegativity (2.55) and creates a partial negative charge. This leaves the other parts of the molecule with a partial positive charge.  

Acetone is considered to be the simplest "ketone" i.e. hydrocarbon containing a double-bonded oxygen to a carbon somewhere along the structure. This difference contributes to the polar dipole present within the molecule. When combined with the temporary London Dispersion Forces (LDFs) present within Acetone, we find that the structure has a relatively high melting point and boiling point of -95˚C and 56˚C, respectively. Therefore acetone is a liquid at Standard Temperature and Pressure. Although acetone is not regarded as a toxic molecule and no serious detrimental effects have been observed from exposure, it is nevertheless extremely flammable at temperatures where humans are handling it. However, most industrial acetone contains a small amount of water which prevents this kind of explosion from occurring. 

Acetone Ball and Stick Model
Acetone Ball and Stick Model. Created with MolView.
How is acetone utilized in the real world?

Since the compound is less polar than water, it serves as a solvent for many different intermediately polar molecules both in industrial and research capacities. For example, superglue is able to dissolve in acetone before hardening into its final form. Another example is acetylene (C2H2) which can dissolve in acetone and thereafter be safely transported. C2H2 cannot be safely pressurized in its pure form which is why acetone is required in this process. Furthermore, since acetone is a basic ketone it is utilized as an intermediate molecule in the formation of many more complex ketones and hydrocarbons. Acetone also finds extensive usage in the laboratory in order to clean glassware after complex chemistry experiments.