Question

On mixing 25 ml of acetone with 25 ml of ethyl alcohol, the total volume of the solution is
A. = 50 ml
B. > 50 ml
C. < 50 ml
D. unpredictable

Answer 1

Hint: Before solving this question, let’s understand the term hydrogen bonding. When a hydrogen bond from one molecule comes in contact with the electronegative atoms such as oxygen, nitrogen, fluorine etc. there is a development of electrostatic force of attraction known as hydrogen bonding.

Complete step by step answer:
As we know that hydrogen bonding is another one of the most important binding forces than covalent and ionic bonding. It is another class of attractive forces that arises due to the presence of dipole-dipole interaction between hydrogen atoms which is bonded to a highly electronegative atom.
Given in the question that 25 ml of acetone and 25 ml of ethyl alcohol is mixed together.
The chemical formula of acetone is ${{(C{{H}_{3}})}_{2}}CO$ and the chemical formula of ethyl alcohol is ${{C}_{2}}{{H}_{5}}OH$. When both of them are mixed together, there is formation of hydrogen bond among the oxygen of acetone and hydrogen of acetyl alcohol. And due to the formation of hydrogen bonding between acetone and ethyl alcohol the molecules come close to each other which leads to the decrease in volume of the solution. Hence, the volume of the solution will be less than the total volume of acetone and ethyl alcohol.

Hence the correct answer is option C.

Note: It is interesting to note that the mixture of ethanol and acetone shows positive deviation from Raoult's law which means that the vapour pressure of the non-ideal solution is higher than the vapour pressure which is predicted by Raoult's law.