Experiment: Three Component Separation
Week 2

Emulsions will most likely occur with your 3-component separations. Remember that an emulsion is the mixed phase at the interface of the organic and aqueous layers that have not yet been able to separate into distinct layers. You have read that the addition of brine to the mixture will help remove the emulsion. After removing the aqueous layer in the first part of the experiment (containing the m-nitroaniline hydrochloride), and neutralizing it with NaOH, check to see if the emulsion (if any) in your separatory funnel has cleared up. If it has, then add the remaining aqueous layer to your existing neutralized aqueous portion. This step will enable you to recover more of the m-nitroaniline in the entire mixture. Another technique that can aid in removing all aqueous layers is the gentle swirling of the separatory funnel after each removal of the aqueous phase. After swirling, place the separatory funnel in the ring stand and wait about 30 seconds. You will often see more aqueous phase appearing at the bottom of the separatory funnel.

You may use the lab air valves at both ends of the lab (orange valves marked "LA") to evaporate the ether from your organic layer containing naphthalene (last step). Be sure to use a gentle stream of air!

If you are not able to obtain the melting points of each of your components, you may use the FIRST 2 HOURS of any other lab period before your next scheduled section to complete them.