Question

Which of the following conditions are correct for real solutions showing negative deviation from Raoult's law?

• A. $\Delta H_{Mix}<0;\Delta V_{Mix}>0$
• B. $\Delta H_{Mix}>0;\Delta V_{Mix}>0$
• C. $\Delta H_{Mix}>0;\Delta V_{Mix}<0$
• D. $\Delta H_{Mix}<0;\Delta V_{Mix}<0$

Answer 1

The correct option is D $\Delta H_{Mix}<0;\Delta V_{Mix}<0$

The following conditions are correct for real solutions showing negative deviation from Raoult's law.

$\Delta H_{Mix}<0;\Delta V_{Mix}<0$

For such solutions, the total vapour pressure is less than that expected from Raoult's law.

The new interactions are stronger than the interactions in pure components.