Which of the following in each pair is likely to be more soluble in hexane, \(\mathrm{C}_{6} \mathrm{H}_{14}:\) (a) \(\mathrm{CCl}_{4}\) or \(\mathrm{CaCl}_{2}\); (b) benzene \(\left(\mathrm{C}_{6} \mathrm{H}_{6}\right)\) or glycerol, \(\mathrm{CH}_{2}(\mathrm{OH}) \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{2} \mathrm{OH} ;\) (c) octanoic acid, \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{COOH},\) or acetic acid, \(\mathrm{CH}_{3} \mathrm{COOH}\) ? Explain your answer in each case.

Hexane is a nonpolar solvent. Its formula is \(\mathrm{C}_{6} \mathrm{H}_{14}\). Now, let's analyze the polarity of all the solute compounds given: (a) 1. Carbon Tetrachloride (\(\mathrm{CCl}_{4}\)) is a nonpolar molecule. It has a tetrahedral geometry, and the equal distribution of the chlorine atoms cancels out any dipole moments. 2. Calcium Chloride (\(\mathrm{CaCl}_{2}\)) is an ionic compound, which is highly polar. (b) 1. Benzene (\(\mathrm{C}_{6} \mathrm{H}_{6}\)) is a nonpolar molecule with a planar hexagonal structure. The electron cloud in the ring of carbons is delocalized and spread evenly across the whole molecule. 2. Glycerol (\(\mathrm{CH}_{2}(\mathrm{OH}) \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{2} \mathrm{OH}\)) is a polar compound due to the presence of three hydroxyl groups that contribute to hydrogen bonding. (c) 1. Octanoic acid (\(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{COOH}\)) is a fatty acid and has both a nonpolar hydrocarbon chain and a polar carboxyl group. However, its long hydrocarbon chain reduces the overall polarity. 2. Acetic acid (\(\mathrm{CH}_{3} \mathrm{COOH}\)) is a highly polar molecule with a carboxyl group.

Now, let's select the compound from each pair that is more likely to be soluble in hexane: (a) \(\mathrm{CCl}_{4}\) is likely to be more soluble in hexane since it is nonpolar, and hexane is nonpolar as well. (b) Benzene is likely to be more soluble in hexane as it is nonpolar and has similar properties to hexane, whereas glycerol is highly polar due to the presence of hydroxyl groups. (c) Octanoic acid is expected to be more soluble in hexane since it has a long nonpolar hydrocarbon chain, even though it also has a polar carboxyl group. Acetic acid has a higher polarity due to the carboxyl group, thus being less soluble in hexane. To summarize, the more likely soluble compounds in hexane are: (a) \(\mathrm{CCl}_{4}\), (b) Benzene, and (c) Octanoic acid.