Question

From the following which is/are true regarding minimum boiling azeotropes?

• A. $\Delta H_{mix}>0$
• B. $\Delta V_{mix}<0$
• C. $\Delta S_{mix}>0$
• D. $\Delta G_{mix}<0$

Answer 1

Answer: (A), (C), (D)

$\Delta G_{mix}<0$

Minimum Boiling azeotropes:
Minimum boiling azeotropes are those which boil at a lower temperature than boiling point of each component in the pure state. Consequently vapour pressure of the mixture is higher than each component.
Example $95.5\%$ ethyl alcohol and $4.5\%$ water by mass forms a minimum boiling azeotrope


Here,

$\Delta H_{mix}>0$
$\Delta V_{mix}>0$
$\Delta S_{mix}>0$
$\Delta G_{mix}<0$