An ideal solution in chemistry is characterized by zero enthalpy and volume of mixing, typically observed when components share similar molecular dimensions and intermolecular forces. Let's examine the provided solutions:
n-hexane and n-heptane: As alkanes with comparable structures and intermolecular forces, these are expected to form an ideal solution.
Benzene and toluene: These aromatic compounds, possessing similar sizes and van der Waals forces, are likely to exhibit ideal behavior.
Bromoethane and chloroethane: Their similar structures as haloalkanes suggest they will likely form an ideal solution.
Ethanol and acetone: Ethanol, an alcohol with hydrogen bonding, differs in intermolecular forces from acetone, a ketone with dipole interactions, leading to non-ideal behavior.
Therefore, the pair demonstrating non-ideal solution behavior is ethanol and acetone.
The freezing point depression constant (\( K_f \)) for water is \( 1.86 \, {°C·kg/mol} \). If 0.5 moles of a non-volatile solute is dissolved in 1 kg of water, calculate the freezing point depression.