Is Grease Dissolving in Soapy Water a Physical or Chemical Change?

This oil and grease will not dissolve in water.
••• John Foxx/Stockbyte/Getty Images

If you have ever tried to clean a greasy pan without soap, you know that fats, oils and other nonpolar substances do not dissolve in water. At best, they congregate into large droplets. Soaps, however, are special molecules with a hydrophilic head and a hydrophobic tail, and they spontaneously organize into tiny spheres with hydrophobic interiors that can dissolve nonpolar compounds. But is the dissolving process physical or chemical in nature?

Physical and Chemical Changes

The key difference between a chemical change and a physical change is that molecular chemical nature is not affected by a physical change. For example, boiling water is a physical change because the water molecules are still water molecules. When a molecule dissolves, it is simply surrounded by the molecules of the solvent -- its chemical composition has not changed. Therefore, when grease dissolves in soapy water, it is merely going through a physical change.

Related Articles

What Are Two Major Characteristics of a Molecular Compound?
How to Calculate Solubilities
Why Does Sugar Affect the Freezing Point of Water?
Which Lipids Are Water Soluble?
Why Do Hydrates Change Color When Heated?
What Does Soluble Mean in Science?
What Happens to Ionic & Covalent Compounds When They...
Are Ions Hydrophobic Or Hydrophilic?
What Are True Statements About a Compound?
Three Ways That Polarity of Water Molecules Affect...
What Are the Monomers of Triglycerides?
What is the Definition of Dissolve in Chemistry?
What Is in Corn Syrup That Makes a Bubble?
Glycerol Vs. Mineral Oil
Does Oil Dissolve Rubber Gloves?
How Does a Sugar Crystal Grow?
Difference Between Triglycerides & Phospholipids
Physical Properties of Urea
Molecular Activity of Water Vs. Oil
How to Make Flubber Without Borox or Liquid Starch

Dont Go!

We Have More Great Sciencing Articles!