Soap Chemistry

 Have you realized that you can’t just clean anything with water? When I say “soap,” what is the first thing that comes to mind? You might immediately think of hand soap. You might also think of detergent, which helps wash your dishes and your clothes. All in all, we need soap and detergents to remove dirty stains and soil from our bodies and our things.

In terms of chemistry, a soap is a type of salt formed from the mixing of an acid and a base. Acids and bases are chemicals. Most liquids are acids or bases. In order to determine if a liquid is an acid or base, the liquid is judged by the type of ions it has. If a liquid has many hydrogen ions, then the liquid is an acid. If the liquid has many hydroxide ions, then it is a base. Soaps and detergents are strong bases, giving it a slippery feeling because bases react with molecules in your body called fatty acids. (If it was a strong acid, the soap would burn your skin.) Soap is created by mixing a base with fatty acids. When the base touches your skin when you wash your hands, your fatty acids and the base actually produce the soap on your hands.

Soap is also known as a surfactant, meaning soap reduces water’s surface tension, allowing soap to easily get rid of grease. Soap is also hydrophobic, which allows it to be attracted to the dirt and get rid of it. At the same time, soap is also attracted to water, making it hydrophilic. This allows the soap mixture to be washed away when you rinse with water.

The next time you wash your hands or your clothes, carefully observe the process!

Soap that you use to wash your hands

Picture Credit: treehugger.com