Question

When ethyl alcohol is dissolved in water it is accompanied with :

• A. absorption of heat and contraction in volume
• B. evolution of heat and contraction in volume
• C. absorption of heat increase in volume
• D. evolution of heat and increase in volume

Answer 1

The correct option is B evolution of heat and contraction in volume

When alcohol is dissolved in water, the formation of H-bonds takes place between the water molecules and alcohol molecules.

Due to H-bond formation heat energy is liberated, hence, the reaction is exothermic.

Also due to the formation of H-bond, water and alcohol molecules come closer which causes a reduction in the final volume of solution thereby an increase in the density of the solution.

Therefore, the option is B.