Question

. Scenario: you are doing your aqueous wash with (mildly basic!) NaHCO3 (step

6), and cap the separatory funnel while chatting with your lab partner about your exciting weekend. The cap flies off and hits the sealing with a loud “bang!”; embarrassment ensues. Please describe the chemical reaction that occurred, with a mechanism and a drawing, and explain how you can prevent this from happening while performing this aqueous wash step. Also: what starting material/solvent do you think this wash (which is basic!) is attempting to remove. (Feel free to research your answer to this).

Answer 1

The cap flies because of the formation of CO₂ gas inside the separating funnel, since we know that NaHCO₃is mild basic in nature so there must be some acidic species present inside the separating funnel , and in the given scenario mild base is used this also confirms that whatever compound is present in separating funnel is weak acidic in nature, preferably formic acid or acetic acid so a very usual acid base reaction is happening inside which produces CO₂ gas.

Method to avoid such situation

In separating funnel only way to release pressure is from the top mouth so we must release pressure after each shacking of the funnel, and never keep separating funnel with close cap during workup process, the reaction is given below