Question

50 ORGANIC CHEMISTRY LABORATORY TECHNIQUES ON SEPARATION PURIFICATION Name - Date - A truck driver hauling some unmarked chemicals decided to beat the train; unfortunately, the train hit the truck, crushed it and all the chemicals spilled, mixed, and drenched in the soil. Before the driver died, he told the fire chief that there were six containers of organic compounds. He did not mention the names of the compounds but he stated in a faint voice that two of the three acids are water soluble and the last acid is insoluble in water but soluble in dichloromethane. The other three liquid compounds have the following boiling points 79.2 "C, 160°C, and 210°C, Devise a method for the separation and purification of these six compounds.

Answer 1

Total number of acids - six.

Two are water soluble and one in dichloromethane.

Charge water and dichloromethane in equal portions (~10 volumes each corresponding to the container size) and charge the acid mixtures. Shake/stir well. Allow to separate the layers. The dichloromethane layer will have one of its miscible acid and water will have the other two acids.

Distill the dichloromethane layer to get the required acid. Monitor the boiling points. Dichloromethane will get distilled at 39.6 C. Discard the distillate. Collect any fractions that boils at 79.2 C or 160 C or 210 C ss the solubility of the remaining three acids were not known. If none, all the five acids would have dissolved in water and can be separated through fractional distillation by distilling at its respective boiling points.