Q11 / 180 · KCET 2014 · Chemistry
For an ideal binary liquid mixture
- A\( \Delta \mathrm{H}_{(\text {mix })}=0 ; \Delta \mathrm{S}_{(\text {mix })} < 0 \)
- Correct answerB\( \Delta \mathrm{S}_{(\mathrm{mix})}>0 ; \Delta \mathrm{G}_{(\mathrm{mix})} < 0 \)
- C\( \Delta S_{(\mathrm{mix})}=0 ; \Delta G_{(\mathrm{mix})}=0 \)
- D\( \Delta \mathrm{V}_{(\text {mix })}=0 ; \Delta \mathrm{G}_{(\text {mix })}>0 \)
Solution
For an ideal binary liquid mixture $\Delta S_{\operatorname{mix}}>0$ and $\Delta G_{\operatorname{mix}} < 0$
For ideal solution;
$\Delta H_{\operatorname{mix}}=0$ and $\Delta V_{\operatorname{mix}}=0$
$\Delta G=\Delta \mathrm{H}-\mathrm{T} \Delta S$
$\Delta G$ should be $-$ ve for reaction to be spontaneous, that is, $\Delta G < 0$.
When $\Delta G < 0$, then $\Delta S$ should have value greater than zero
Hence, the correct answer is option: 'B'.