Question

$100mL$ of liquid 'A' and $25mL$ of liquid 'B' are mixed to form a solution of volume $125mL$. Then the solution is

Answer 1

When the solute A (liquid) dissolves in the solvent B (liquid), the extent of dissolution depends on interation of A-A, B-B and A-B.
Here, $100mL$ of liquid 'A' and $25mL$ of liquid 'B' mixed to form $125mL$. When these two liquids are added their volume became their sum of volume. There is no decrease or increase in volume after dissolution. This implies that the interaction of A and B is equal to the interaction of A-A and B-B.
For ideal solution, solvent-solute interaction is equal to solvent-solvent and solute-solute interactions.
$\Delta V_{mix}=0$ hence, the solution is ideal.