Class 12 chemistry PYQ - solution - chapter

Q6: The mixture which shows positive deviation from Raoult’s law is :    

(a) Acetone + Chloroform                          (NEET 2020)
(b) Chloroethane + Bromoethane
(c) Ethanol + Acetone
(d) Benzene + Toluene

Ans: (c)        

                                     

Pure ethanol molecules are hydrogen bonded. On adding acetone, its molecules get in between the ethanol molecules and break some of the hydrogen bonds between them. This weakness the intermolecular attractive interactions and the solution shows positive deviation from Raoult's law.