Which one of the following is incorrect for ideal solution?
- Hmix = 0
- Umix = 0
- P = Pobs - Pcalculated by Raoult's law = 0
- Gmix = 0
Answer
(4) Gmix = 0
Solution
As per NCERT, an ideal solution obeys Raoult's law over the entire range of concentration, with mixH = 0 and mixV = 0.
Umix = Hmix - P Vmix = 0 and Pobs = PRaoult, so P = 0.
But mixing increases randomness, Smix > 0:
Gmix = Hmix - T Smix = -T Smix < 0
Gmix = 0 is incorrect.
Answer: (4)