Which one of the following is incorrect for ideal solution?

For an ideal solution, ΔHmix=0,ΔVmix=0, Now, ΔUmix =ΔHmix -PΔVmix ∴ΔUmix =0 Also,for an ideal solution, pA=xApA°,pB=xBpB°∴ΔP=Pobs -Pcalculated by =0ΔGmix=ΔHmix-TΔSmix For an ideal solution, ΔSmix≠0∴ΔGmix≠0