Among the solvents listed, diethyl ether is the least polar solvent.
To understand why, let’s consider the structure and polarity of each solvent:
- Dichloromethane (DCM): This solvent has two chlorine atoms that are highly electronegative, which contributes to its polarity. The presence of chlorine creates a significant dipole moment.
- Diethyl ether: This solvent consists of an oxygen atom bonded to two ethyl groups. The overall molecular structure makes it less polar compared to DCM, largely because the ethyl groups provide a hydrophobic character.
- Ethyl acetate: This solvent contains both a carbonyl (C=O) group and an ether (–O–) moiety, making it noticeably polar due to the electronegative oxygen atom in the carbonyl and ether.
- Water: Known for its high polarity, water has a very strong dipole moment because of its bent shape and the electronegativity of the oxygen atom.
In summary, when we compare the solvent polarities, diethyl ether, with its relatively nonpolar ethyl groups and less pronounced dipole, stands out as the least polar solvent among the choices provided.