Question

Why do we add xylenes to the reaction flask after refluxing in Lab , and what do we use to add them?

a) To cool down the reaction, using a pipette
b) To increase the reaction temperature, using a dropper
c) To dilute the mixture, using a syringe
d) To aid in separation, using a funnel

Answer 1

Xylenes are added to a reaction flask using a funnel to aid in the separation process during a chemical extraction, improving the isolation of the desired product.

Step-by-step explanation:

In a laboratory setting, after refining a substance by refluxing, xylenes may be added to the reaction flask for a few reasons, but primarily to aid in the separation of compounds. This addition is done using a funnel, which allows for the controlled addition of the xylenes without exposing the reaction to moisture from the air or potential contaminants. Xylenes can help wash out impurities and, in a separatory funnel, assist in the extraction process by enhancing the solubility of the desired product in an organic phase separate from the aqueous layer, which allows for an easier and more efficient separation.

The process of using a separatory funnel involves pouring the two immiscible liquids into the funnel, shaking it to allow the phases to come into intimate contact, and then letting the liquids settle into layers, which can be separated by density via the stopcock at the bottom.