You're welcome! I'm glad I could help clarify things for you. Remember, when it comes to solubility, "like dissolves like." This means that compounds with similar intermolecular forces tend to dissolve in each other.
In the case of ethylene glycol (HOCH2CH2OH) in hexane (C6H14) or H2O, ethylene glycol is a polar molecule due to the presence of the hydroxyl (OH) groups. Hexane, on the other hand, is nonpolar. Since ethylene glycol is polar and water is also polar, ethylene glycol is more likely to dissolve in water rather than in hexane.
For diethyl ether (CH3CH2OCH2CH3) in H2O or CH3OH, diethyl ether is a relatively nonpolar molecule. Both water and methanol (CH3OH) are polar solvents. However, due to the nonpolar nature of diethyl ether, it is likely to dissolve better in the less polar solvent, which in this case is CH3OH (methanol).
When it comes to NaCl in CH3OH or CH3CH2CH2CH2OH, NaCl is an ionic compound composed of sodium cations (Na+) and chloride anions (Cl-). Ion-dipole interactions occur when ions interact with polar molecules. Since CH3OH is a polar molecule, it would likely dissolve NaCl more readily than CH3CH2CH2CH2OH (butanol), which is less polar.
The number of hydrogen atoms (H) in the chain of a compound does not directly affect polarity. The presence of functional groups such as OH (as in alcohols) or O (as in ethers) contributes more to the overall polarity of a molecule.
Remember, when in doubt, it's always a good idea to use reputable online resources or textbooks to confirm your understanding and gather more information.