Why is ethanol miscible in water?

Ethanol is a type of alcohol that is considered miscible or soluble in water.  When mixed with water, ethanol will easily combine with the water molecules.  Both water and ethanol contain so-called polar molecules that are able to form hydrogen bonds.  These bonds are made with a mixture of the molecules from ethanol and water.  Because of this property, ethanol is able to mix with water easily.

In terms of molecule size, ethanol has smaller molecules when compared to water.  This property also contributes to the easy miscibility, or mixing ability, of both liquids with each other.  With the smaller molecules, ethanol molecules literally fill the gaps in between the bigger molecules from water.  This also explains the volume change when ethanol is mixed with water.  Like in the case of 10 ml of water being combined with ethanol with the same amount, the resulting mixture will not actually register an exact 20 ml reading.  Instead, the ethanol-water mixture may yield only about 19ml because of the way the molecules bind with each other.  The smaller ones fall in between the big molecules, and so some volume may be taken out from the mixture’s reading.

Ethanol is a widely used alcohol for a variety of purposes.  Much of its use is in the making of alcoholic beverages like beer and wine.  The alcohol content in these beverages may be as low as 5 percent and may rise to almost 40 percent depending on the type and brand of beverage.  Light alcoholic drinks are those that contain less ethanol while hard drinks contain 20-40 percent of this liquid.  Aside from its wide use in the making alcoholic drinks, ethanol is also used as an antiseptic agent, as fuel for machines, as solvents in various drugs and in perfumes, and as preservatives in the field of science and/or medicine.