Which solvent, water or hexane \(\left(\mathrm{C}_{6} \mathrm{H}_{14}\right)\), would you choose to dissolve each of the following? a. \(\mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}\) d. \(\mathrm{CH}_{3}\left(\mathrm{CH}_{2}\right)_{16} \mathrm{CH}_{2} \mathrm{OH}\) b. \(\mathrm{CS}_{2}\) e. \(\mathrm{HCl}\) c. \(\mathrm{CH}_{3} \mathrm{OH}\) f. \(\mathrm{C}_{6} \mathrm{H}_{6}\)

Water is a polar solvent, as oxygen is more electronegative than hydrogen, leading to a partial negative charge on oxygen and a partial positive charge on hydrogen atoms. Hexane, on the other hand, is a nonpolar solvent comprised of carbon and hydrogen atoms only, with minimal differences in electronegativity, and therefore no significant positive or negative charges on the molecule.

a. Copper nitrate (Cu(NO₃)₂) is a polar compound as it contains ionic bonds between copper (Cu²⁺) and nitrate (NO₃) ions. d. CH₃(CH₂)₁₆CH₂OH is a large nonpolar hydrocarbon with a small polar hydroxyl (-OH) group at the end, so it's mostly nonpolar. b. Carbon disulfide (CS₂) is a nonpolar compound as both carbon and sulfur have similar electronegativities, and there is no charge separation within the molecule. e. Hydrogen chloride (HCl) is a polar compound due to the electronegativity difference between hydrogen and chlorine atoms, leading to a partial positive charge on hydrogen and a partial negative charge on chlorine. c. Methanol (CH₃OH) is a polar compound due to the electronegativity difference between oxygen and hydrogen atoms in the hydroxyl group. f. Benzene (C₆H₆) is a nonpolar compound comprising carbon and hydrogen atoms only, with no significant electronegativity difference.

a. For Cu(NO₃)₂, choose water as the solvent because both are polar. d. For CH₃(CH₂)₁₆CH₂OH, choose hexane as the solvent because the molecule is mostly nonpolar. b. For CS₂, choose hexane as the solvent because both are nonpolar. e. For HCl, choose water as the solvent because both are polar. c. For CH₃OH, choose water as the solvent because both are polar. f. For C₆H₆, choose hexane as the solvent because both are nonpolar.