Question

If liquids A and B form an ideal solution, then

• A. the enthalpy of mixing is zero
• B. the entropy of mixing is zero
• C. the free energy of mixing is zero
• D. the free energy as well as the entropy of mixing are each zero

Answer 1

Answer: (A)

the enthalpy of mixing is zero

Answer 2

If liquids A and B form ideal solutions, then the enthalpy of mixing is zero.

An ideal solution is the solution which obeys Raoult's law at all concentrations. Such solutions are formed by mixing components having same molecular size, structure and similar intermolecular forces. For an ideal solution,

$\Delta H_{mix}$= 0

$\Delta V_{mix}$ = 0

where, $\Delta H$ = Change in Enthalpy and $\Delta V$ = Change in Volume