Is used cooking oil homogeneous or heterogeneous?

* Homogeneous mixtures have a uniform composition throughout. Think of salt dissolved in water - every part of the solution tastes the same.

* Heterogeneous mixtures have varying compositions. You can see different parts of the mixture, like sand and water.

Used cooking oil often contains:

* Solid particles (food bits, crumbs, etc.) that settle to the bottom

* Water droplets that don't mix with the oil

* Varying levels of fat and impurities throughout the mixture

Because these components are not uniformly distributed, used cooking oil is considered heterogeneous.