Question

Condition for spontaneity in an isothermal process is

• A. $\Delta A + W < 0$
• B. $\Delta G + U < 0$
• C. $\Delta A + U > 0$
• D. $\Delta G - U < 0$

Answer 1

Answer: (A)

$\Delta A + W < 0$

Answer 2

The condition for spontaneity in an isothermal process is that $\Delta G$ should be negative.
$\because \Delta G=\Delta A+P \cdot \Delta V$
$\Delta G=\Delta A+W \quad(\because W=P \cdot \Delta V)$
$\therefore$ For spontaneity in an isothermal process:
$\Delta A+W < 0$