The Effects of Washing Organic Layer With Sodium Carbonate

In organic chemistry, one of the more common experiments is extraction. Extraction is performed to remove an organic acid from a solvent (often water). The mixtures, since they are immiscible (i.e. cannot mix together) form two layers--an organic and an aqueous (water-based) layer. A compound that is often isolated using this method is methylene chloride, which is often the basis of paint stripping mixtures. A vital part of the process is the washing of the organic layer with sodium carbonate.

Removing Alkaline Material

• Sometimes the organic layer, when derived from an acidic solution, should be washed with sodium carbonate, which is a base. A salt is formed in this reaction that is soluble in water and will be flushed out with the aqueous phase.

Keeping the Two Layers Separate

• Washing the organic layer with sodium carbonate also helps to decrease the solubility of the organic layer into the aqueous layer. This allows the organic layer to be separated more easily.

Separating a Homogenous Mixture

• If the organic and aqueous layer are in a homogenous mixture (a clear appearance with distinction), then sodium carbonate can be effective in separating the two layers.