Question

The correct option(s) for a solution showing positive deviation is/are:

• A. Solvent-solute interaction is less than the solvent-solvent and the solute-solute interactions
• B. Solvent-solute interaction is more than the solvent-solvent and the solute-solute interactions
• C. Enthalpy of mixing is less than zero i.e. $\Delta H_{mix}<0$
• D. Both (b) and (c)

Answer 1

The correct option is A Solvent-solute interaction is less than the solvent-solvent and the solute-solute interactions

Positive deviation:
Solvent-solute interaction is less than the solvent-solvent and the solute-solute interactions

For positive deviation:

$\Delta H_{mix}>0$
$\Delta S_{mix}>0$
$\Delta G_{mix}<0$
Examples: Ethanol and Acetone, $C{S}_2$ and acetone