Question

You carefully pour what is left in the separatory funnel into a 100-mL Erlenmeyer flask from the top of the separatory funnel. taking care not to transfer any water droplets. you add about 8g of anhydrous sodium sulfate to this solution. What does this solution contain? what is the purpose of using anhydrous sodium sulfate? what other compound/compounds could have been used in place of this salt?

Answer 1

The solution contain organic compound having traces of water (which have to be removed) in it.

Anhydrous sodium sulfate absorb traces of water in the organic sample.

In aqueous extractions some water will be transferred into the organic phase because of the partial miscibility of the organic phase and water. Also, many reactions themselves are performed in an aqueous solution. This water must be removed before the required compound can be properly characterized. Traces of water are removed by treating the organic solution with a drying agent. A drying agent is an inorganic salt which readily takes up water to become hydrated. Several such salts are used routinely in the organic chemistry teaching labs, e.g. , calcium chloride (CaCl2), sodium sulfate (Na2SO4), calcium sulfate (CaSO4) and magnesium sulphate (MgSO4), found in an anhydrous state.