An ideal solution is a homogeneous mixture which (ΔmixS=0) obey Raoult's law. For ideal solution, we need ΔmixH=0 and ΔmixV=0 but ΔmixS≠0 i.c. ΔmixS>0 obey Raoult's law at every range of concentration for ΔmixS>0. Number of molecule = entropy increase ΔmixG=ΔH−TΔS ΔmixG=−TΔS<0 e.g., benzene + toluene (show ideal solution)