What Happens When You Mix Isopropyl Alcohol And Water? Is It Gonna Be Harmful?

Do you remember the time when you are accidentally tripped and fell down? You got your knee grazed because of this. For sure the first thing you do was looking for the first-aid kit. You searched for antiseptics and applied it to the injured skin.

From this everyday experience, we learn that antiseptics are useful for reducing the chance of infection to happen on your skin. It has this use because of one of its ingredient, isopropyl alcohol.

Where else can we find isopropyl alcohol? We can find it in other common household chemicals, such as disinfectants and detergents. The example of disinfectant is a wet wipe.

People use it as a simple way to clean their hands when there is no water nearby. Just like the benefit in the product such as antiseptics and wet wipes, isopropyl alcohol is also a beneficial ingredient of the detergent. This chemical helps to remove stains. It can even put off the ink stain.

You can also make use of the isopropyl alcohol for making your own windshield washer fluid. It is very easy. You just need to mix the dish soap, water, and isopropyl alcohol. It is cheaper than buying the fluid from the shops and also very quick to make. From this home-made experience of using chemical, we see that isopropyl alcohol is able to be mixed with water. So, what happens when you mix isopropyl alcohol and water? Let’s find out!


Mixing Isopropyl Alcohol And Water

Isopropyl Alcohol is a compound with characteristics such as colorless, flammable, has a strong odor, and miscible in water. Miscible means what happens when you mix isopropyl alcohol and water is the forming of a homogeneous solution. What is the process of this? 

What makes two compounds to be mix and form a homogeneous solution, both compounds have to possess molecules which attract each other. There are two kinds of molecules, polar and nonpolar. Polar molecules have an unevenly distributed electric charge. It means it has one side with a more positive electric charge and another side with a more negative electric charge. Polar molecules are also able to form hydrogen bonds. Nonpolar molecules are the opposite of polar molecules. It has an equally distributed balance charge.

Isopropyl alcohol has both polar and nonpolar molecules. Based on its structural formula, it has three carbons, each attached with hydrogen. These ones are nonpolar. Besides those molecules, there are also the hydrogen and oxygen. These two are nonpolar because they have partial positive and negative charge respectively.

Different from isopropyl alcohol, water molecules are polar. In the structural formula, it has oxygen and two hydrogens. The oxygen has a part of negative charge and both hydrogens have a part of a positive charge. As a result, hydrogen bonds are formed. From these descriptions, we can conclude that water is highly polar and, on the other side, isopropyl alcohol is less polar.

This is what happens when you mix isopropyl alcohol and water. There is a competition between the hydrogen bonds in the water with the hydrocarbon in the isopropyl alcohol. During the process of mixing, the first thing that will happen is the breaking of the hydrogen bonds. It requires energy to break the bond. The energy comes from the process of forming hydrogen bonds by the water with the isopropyl alcohol‘s OH. The energy released by this process is bigger than what is needed to break the bond.

The Boiling Point

Another thing that happens when you mix you isopropyl alcohol and water together is a solution with a boiling point of 80.370C. Isopropyl alcohol boils at 82.60C while the water boils at 1000C. The solution to this characteristic is called azeotrope.

In this case, the mixing solution of isopropyl alcohol and water forms a positive azeotrope. It means the solutions’ boiling point is less than its compound. The opposite of this a negative azeotrope which boiling point is greater than its compound.


As mentioned above, antiseptic contains isopropyl alcohol. This rubbing-alcohol antiseptic is formed by the mixing of isopropyl alcohol and water.

Because of its ability to kill germs and bacteria, as well as disinfect minor wounds, isopropyl alcohol is also an ingredient for various products not only at home but also at the hospitals. Alcohol swabs (the one doctors use to clean our arm before injection) and hand sanitizer are among the products that make use of isopropyl alcohol. The conclusion from those examples is that isopropyl alcohol is beneficial both as a single ingredient and mixed ingredient.