Question

Water and dichloromethane are insoluble in each other. When each is added to a test tube, two layers form. Which layer is water, and which is dichloromethane?

Short answer

Answer: In a test tube containing water and dichloromethane, the top layer will be water and the bottom layer will be dichloromethane.

Step-by-step solution

Find the densities of water and dichloromethane

First, we need to find the densities of water and dichloromethane so we can compare them. The density of water is approximately 1.0 g/mL, and the density of dichloromethane is approximately 1.325 g/mL.

Determine which substance is less dense

Now that we have the densities of both substances, we can determine which substance is less dense. We see that water (1.0 g/mL) is less dense than dichloromethane (1.325 g/mL).

Identify the layers based on density

Since water is less dense than dichloromethane, it will form the top layer in the test tube. Dichloromethane, being denser, will be the bottom layer. To conclude, in a test tube containing water and dichloromethane, the top layer is water and the bottom layer is dichloromethane.