Final answer:
Ammonium hydroxide is added to adjust the pH and promote extraction of the compound. It can also neutralize acidic impurities.
Step-by-step explanation:
Ammonium hydroxide is added to the separatory funnel with dichloromethane (DCM) and cola in order to adjust the pH of the aqueous phase. Ammonium hydroxide is a base and can increase the pH, making it favorable for the extraction of certain compounds.
When a compound is dissolved in an organic solvent like DCM, it will not be extracted into the aqueous phase unless the pH of the aqueous phase is adjusted to favor the transfer. Ammonium hydroxide provides the necessary basic conditions for this transfer to occur.
Additionally, ammonium hydroxide can help to neutralize any acidic impurities or contaminants in the mixture, improving the purity of the extracted compound.