Question

Which of the following is polar aprotic solvent?
(A) DMSO
(B) Crown ether
(C) DMF
(D) All of these

Answer 1

There are different solvents that are used in organic chemistry to carry out the different reactions. They have different heteroatoms as well containing oxygen, nitrogen, sulphur, phosphorus, etc. Those that contain $\text{N-H}$ bonds and $\text{O-H}$ bonds fall under one category and those that do not fall under another category.

Complete Step by Step Answer
A solvent is a liquid that is used to dissolve the reactants of a chemical reaction. It serves two main purposes, one is to dissolve the reactants and the other as an acid or a base or a nucleophile. There are two different categories into which the solutes can be categorized. The first category being that of polar solvents and the other being that of the non-polar solvents. Those that have a net resultant dipole moment are called “polar solvents”, while those solvents that do not have polarity are called “non-polar solvents”. Examples of polar solvents are water, alcohols, low molecular weight carboxylic acids, etc. the examples of non-polar solvents include hydrocarbons with 5 to 10 carbon atoms.
The polar solvents can be further be subdivided into two categories:
The polar aprotic solvents are those that do not contain $\text{N-H}$ bonds and $\text{O-H}$ bonds and therefore cannot form intramolecular or intermolecular hydrogen bonds. Example: Dimethyl Sulfoxide or DMSO. Whereas, the polar protic solvents are those that contain the $\text{N-H}$ bonds and $\text{O-H}$ bonds, and thus participate in intermolecular hydrogen bonding. Examples include alcohols, amines, etc.
Hence, the correct option is D.

Note
The polar or nonpolar nature of any compound can also be determined from its solubility in a solvent. As like dissolves like, polar solvents dissolve polar compounds while the non-polar solvents dissolve non-polar compounds.