How would you determine the relative density of two solvents that are not miscible?

Question

Mateo Aguilar · Accepted Answer

Which is the solvent that ends up as the bottom layer when you mix the solvents in a separating funnel?

The bottom layer is the solvent with greater density. Typically, when you do a solvent extraction, the organic layer floats ON TOP of the water (because, typically, organic solvents have densities #<1*g*mL^-1#). Of course (i), methylene chloride, #CH_2Cl_2#, which is a commonly used organic solvent, has a density of #1.33*g*mL^-1#. Would the pure solvent float or sink in a separating funnel when layered with water? Of course (ii), when you do solvent extractions, because the solute might be partitiioned across the phases and cause density to alter, sometimes you do not know which layer is which.

Xavier Avery · Answer

undefined To determine the relative density of two solvents that are not miscible, you would use a method called the "separation funnel method." This involves adding a known volume of each solvent to a separation funnel, allowing them to separate into distinct layers based on their densities, and then measuring the volume of each layer. By comparing the volumes of the two layers, you can calculate the relative density of the two solvents.