Question

As you are cleaning out the shared refrigerator in the kitchen of your apartment at the end of the school year, you find an unlabeled, clear plastic container in the back, left there by one of your roommates. This container is half-filled with something that you notice has separated into two layers: the top one is a dark yellow color, the bottom layer is more greenish. You assume that this biphasic mixture has an aqueous layer and some type of organic layer. Without tasting, smelling, or removing either layer from the container, how can you determine which layer is the aqueous layer using just material found in a typical kitchen

Answer 1

To identify the aqueous layer in a two-phase mixture using kitchen materials, one can add saltwater or water-soluble food coloring to the container to see which layer it mixes with, indicating the presence of the aqueous phase.

Step-by-step explanation:

To determine which layer is the aqueous phase in the unlabeled container using typical kitchen materials, we can perform a simple experiment based on the principle that water is denser than most organic liquids. Since we do not have a laboratory setup, one way to test this could be to add a small amount of saltwater to the container. As saltwater is denser than both water and organic compounds, if the saltwater sinks to the bottom, this indicates that the bottom layer is the organic one, and the top layer is aqueous. Conversely, if the saltwater stays on top of the bottom layer, it implies that the denser saltwater is not able to mix with the denser aqueous layer below, confirming that the greenish bottom layer is indeed water-based.

Another approach is to carefully add a food coloring that is known to be water-soluble. The food coloring, when dropped into the container, should ideally mix with the aqueous layer, thus revealing which of the two layers is water-based.

Answer 2

See explanation

Step-by-step explanation:

The organic layer is always found at the top of the mixture while the aqueous layer is found at the bottom of the mixture.

Therefore, if I use any piece of rod and an empty container found in the kitchen to perform a simple decantation, the top layer that comes out first is the organic layer. The other layer that remains after the top layer has been successfully decanted is the aqueous layer.