Yes, there was a difference in my results between the solubilities of benzophenone in methyl alcohol and benzophenone in hexane. Benzophenone [essentially nonpolar (slightly polar due to the C=O bond)] was soluble in methyl alcohol, but only partially soluble in hexane. The reason for this is that methyl alcohol has an intermediate polarity, whereas hexane is nonpolar. FINISH. At this point I got confused... if benzophenone is basically nonpolar and hexane is nonpolar, then why wasn't benzophenone fully soluble in hexane and why was it fully soluble in methyl alcohol, rather than only partially?

The majority of materials that are soluble in a non-polar solvent like hexane are themselves non-polar, so I would expect that benzophenone which has no long chain part to be largely insoluble in hexane. It should however be soluble in say benzene or toluene.

I am not surprised that benzophenone has some solubility in hexane. Similarly I am fairly sure that it also has a slight solubility in water.

The ketone (C=O) will make the molecule slightly polar and thus soluble in polar solvents.

The solubilities and polarities are not black and white. As you probably realise there is a scale of polarity between non-polar (hexane) and a polar molecule such as water. To add to the complication the structure of the molecule also has to be taken into account, such as can it hydrogen bond and does it have aromatic groups. The old adage of 'like dissolves like' is always a useful starting point.

There is an added complication with ketones in alcohols in that the (C=O) can also react with the alcohol group to form C(OMe)2 (a ketal).

what is the solubility of benzophenone in toluene?

The solubility of a compound in a particular solvent is determined by the nature of its intermolecular forces. In the case of benzophenone, it is true that it is predominantly nonpolar due to the presence of aromatic rings, but it does have a slightly polar carbonyl (C=O) group.

When determining solubility, it is important to consider the like dissolves like principle, which means that compounds with similar intermolecular forces tend to dissolve in each other.

Methyl alcohol (also known as methanol) is a polar solvent because it contains the highly polar hydroxyl (-OH) group. The polar nature of methanol allows it to form hydrogen bonds and interact with the polar C=O group in benzophenone. This ability to form intermolecular interactions facilitates the solubility of benzophenone in methanol, leading to its full solubility.

On the other hand, hexane is a nonpolar solvent. Nonpolar solvents lack the ability to form strong intermolecular interactions with polar compounds. The nonpolar nature of hexane limits its ability to dissolve benzophenone completely because the forces of attraction between the solvent and solute are relatively weak. However, some partial solubility may be observed due to the weak dispersion forces between the nonpolar benzophenone and hexane molecules.

So, in summary, even though benzophenone is considered nonpolar, its partial solubility in hexane can be explained by weak dispersion forces. Its full solubility in methyl alcohol is due to the stronger intermolecular interactions between the polar C=O group in benzophenone and the polar hydroxyl group in methanol.

The solubility of a substance in a particular solvent is dictated by the intermolecular forces at play. In the case of benzophenone, which is essentially nonpolar, its solubility is influenced by the polarity of the solvents. Although benzophenone is nonpolar, it is still capable of experiencing dipole-dipole interactions with polar solvents due to the slightly polar C=O bond.

In methyl alcohol, which has an intermediate polarity, the polar hydroxyl (OH) group can form hydrogen bonds with the C=O group in benzophenone. These hydrogen bonds help break the intermolecular attractive forces between the benzophenone molecules, allowing it to dissolve more fully in methyl alcohol. Therefore, benzophenone shows higher solubility in methyl alcohol because of the formation of favorable dipole-dipole interactions.

On the other hand, hexane is a nonpolar solvent that lacks any functional groups capable of forming hydrogen bonds or other strong polar interactions. As a result, there are no significant attractive forces between the benzophenone molecules and the hexane molecules. The weak London dispersion forces, which are relatively weaker than dipole-dipole interactions, are not sufficient to completely overcome the cohesive forces within benzophenone. As a result, benzophenone remains only partially soluble in hexane.

This discrepancy in solubility of benzophenone between methyl alcohol and hexane can be attributed to the difference in polarity of the solvents and the varying ability of the solvents to engage in intermolecular interactions with the benzophenone molecules.