In the experiment where 40 mg of biphenyl was placed in two test tubes with 1 ml of water and 1 ml of hexane added to each, we would expect to see distinct behaviors in terms of solubility due to the polarity of the substances involved.
Biphenyl is a nonpolar organic compound, while water is a highly polar solvent. As a result, biphenyl will not dissolve well in water. This is because ‘like dissolves like’ – polar solvents typically dissolve polar solutes, and nonpolar solvents dissolve nonpolar solutes. Therefore, in the test tube with water, biphenyl will largely remain separate from the water, indicating low solubility.
On the other hand, hexane is also a nonpolar solvent. This means that biphenyl, being nonpolar as well, will be substantially soluble in hexane. In the test tube containing hexane, we can expect biphenyl to dissolve well, leading to a clear solution.
Regarding hydrogen bonding, it is important to note that biphenyl lacks functional groups that can participate in hydrogen bonding. Hydrogen bonding typically occurs between molecules that have hydrogen atoms bonded to highly electronegative atoms like oxygen, nitrogen, or fluorine. Since biphenyl does not possess such features, hydrogen bonding is not possible for this compound in either water or hexane. Thus, biphenyl’s structural characteristics and the nature of the solvents significantly influence its solubility and interactions.