Question

For which of the following liquid mixtures \(\Delta_\text{mix} H = 0\) and \(\Delta_\text{mix} V = 0\)?

• A. ethyl chloride, ethyl bromide
• B. ethanol, acetone
• C. phenol, aniline
• D. chloroform, acetone

Hint:

Ideal liquid mixtures are those where intermolecular forces of the components are similar, leading to zero enthalpy and volume changes on mixing.

Answer 1

The Correct Option is A

Step 1: Recall conditions for an ideal solution.
An ideal solution has \(\Delta_{mix}H = 0\) and \(\Delta_{mix}V = 0\). This requires nearly identical intermolecular forces, polarity, and molecular size between the two components.

Step 2: Pick the best pair.
Ethyl chloride and ethyl bromide have the same carbon skeleton, similar size, and similar polarity -- they behave almost identically and form a near-ideal solution.
\[ \boxed{\text{Ethyl chloride + Ethyl bromide}} \]