why is the entropy of mixing of an ideal solution non-zero?
Dear Student,
Entropy of mixing of ideal gas is not zero because there is an increase in disorderliness or entropy of a system on dissolution.
Now for ideal solution, ΔHmix = 0
and we know that, ΔGmix=ΔHmix-TΔSmix
or, ΔGmix = -TΔSmix
For the mixing to be spontaneous, ΔGmix <0
In order for ΔGmix <0 , ΔSmix > 0
Hence, entropy of mixing of ideal gas is positive.
Entropy of mixing of ideal gas is not zero because there is an increase in disorderliness or entropy of a system on dissolution.
Now for ideal solution, ΔHmix = 0
and we know that, ΔGmix=ΔHmix-TΔSmix
or, ΔGmix = -TΔSmix
For the mixing to be spontaneous, ΔGmix <0
In order for ΔGmix <0 , ΔSmix > 0
Hence, entropy of mixing of ideal gas is positive.