Question

Extraction procedure and equations:

Thought I'd better post this on the current page. I need the reaction equations checked. I tried to put them in bold but can't. They should all be after Reaction:

Solid benzoic acid, p-nitroaniline and napthalene ->
Dissolve in CH2Cl2 ->
Organic layer: CHCl2 (l) + napthalene(aq)
Future aqueous layer: R-COOH(aq) + R-NH2

Add HCl. Reaction produces R-NH3+Cl- in aq. layer. Repeat extraction ->
Organic layer: CHCl2 (l) and napthalene(aq)
Aqueous layer: RNH3+Cl-(aq) and R-COOH(aq)
Reaction: R-NH2(aq) + HCl(aq) --> R-NH3(aq) + Cl-(aq)

Add NaOH to organic layer. Repeat extraction ->
Organic layer: CHCl2 and napthalene
Aqueous layer: R-COOH-Na+ and H2O
Reaction: R-COOH(aq) + NaOH(aq) --> R-COO-Na+ + H2O(l)

Recovery of each compound:
Napthalene: Wash organic layer twice. (H2O added.) ->
Organic layer: CH2Cl2 and H2O and napthalene
Add anhydrous sodium sulfate (Na2SO4) to organic layer (CH2Cl2) to dry it. ->
Reaction: Na2SO4((aq) + H2O(l) --> 2NaOH(s) + H2SO4(s)
Let CHCl2 evaporate after filtering solids to retrieve napthalene.

Add NaOH to the nitroaniline solution to neutralize. Filter and let dry. ->
Aqueous solution: NaOH and R-NH3+Cl-
Reaction: R-NH3+Cl-(aq) + NaOH(aq) -> R-NH2(s) + NaCl(aq) + H2O(l)

Add HCl to R-COO-Na+ to neutralize. Filter, wash with cold water, and let air dry.
Aqueous layer: R-COO-Na+ and HCl and H2O?
Reaction: R-COO-Na+(aq) + HCl(aq) -> R-COOH(s) + NaCl(aq)

Thanks for the help.

Sheryl


I just wrote a LONG answer to your post, which is now on page 2. You can make your comments on this page but I think I have anwered all of your questions. I hope so.


Very helpful. I have it narrowed down to a few small questions that I need to ask the lab guy. Thanks for that large effort.

Sheryl