IIT JEE , AIEEE Forum - Chemistry , Physical Chemistry

sangeetha5491

when 30ml of ethanol and 30ml of water is mixed, the volume of the resulting solution is less than 60ml. explain this observation.

sandeepramesh

its an azeotropic mixture

sunip_the_mini_mastermind

it is due to negative deviation from raoult's law..... ethanol undergoes hydrogen bonding with water resulting in a volume less the sum of the original volumes

sangeetha5491

wht is an azeotropic mixture?

ramyani

An azeotrope is a mixture of two or more pure compounds (chemicals) in such a ratio that its composition cannot be changed by simple distillation. This is because when an azeotrope is boiled, the resulting vapor has the same ratio of constituents as the original mixture of liquids.

A well known example of a positive azeotrope is 95.6% ethanol and 4.4% water (by weight). Ethanol boils at 78.4°C, water boils at 100°C, but the azeotrope boils at 78.1°C, which is lower than either of its constituents. Indeed 78.1°C is the minimum temperature at which any ethanol/water solution can boil. It is generally true that a positive azeotrope boils at a lower temperature than any other ratio of its constituents.

varshavallig

yup it shows -ve deviation from raoult's law.

characteristics due to -ve deviation are:

V_mix<0

A-A interaction and B-B interaction<A-B interaction

P_total<0

for +ve deviation everything on LHS will b > that on RHS

hope this helps

!!!!!!!!!!!!!!!

drish

yeah its (-)ve deviation from raoult's law

Ask & Discuss Questions with Community & Experts