Question

which solvent could involve ion - dipole interactions with na+
a)
b)
c)
d)
e)

Explanation:

Ion - dipole interactions occur between ions (in this case, \(Na^{+}\)) and polar molecules (molecules with a permanent dipole moment).

• Option a: Carbon tetrachloride (\(CCl_{4}\)) is a non - polar molecule. The symmetric tetrahedral structure of \(CCl_{4}\) leads to the cancellation of individual \(C - Cl\) bond dipoles, so it cannot have ion - dipole interactions with \(Na^{+}\).
• Option b: Acetone (\(CH_{3}COCH_{3}\)) is a polar molecule. The carbonyl (\(C = O\)) group has a significant dipole moment due to the difference in electronegativity between carbon and oxygen. The oxygen atom has a partial negative charge and can interact with the positively charged \(Na^{+}\) ion through ion - dipole forces.
• Option c: Pentane (\(C_{5}H_{12}\)) is a non - polar hydrocarbon. Hydrocarbons generally have very small or no permanent dipole moments (due to the similar electronegativities of \(C\) and \(H\) and the symmetric structure in the case of straight - chain alkanes like pentane), so it cannot have ion - dipole interactions with \(Na^{+}\).
• Option d: Cyclohexane (\(C_{6}H_{12}\)) is a non - polar molecule. The \(C - C\) and \(C - H\) bonds have very small dipole moments, and the cyclic structure leads to the cancellation of any small bond dipoles, so it cannot have ion - dipole interactions with \(Na^{+}\).
• Option e: Benzene (\(C_{6}H_{6}\)) is a non - polar molecule. The delocalized \(\pi\) - electron system and the symmetric hexagonal structure of benzene lead to the cancellation of any potential bond dipoles (the \(C - C\) and \(C - H\) bonds have very small dipole moments), so it cannot have ion - dipole interactions with \(Na^{+}\).

Answer:

B.