[mrmedic]

I really need help understanding this. Ok here goes:

If you were have a mixture of benzamide and 4 methylcyclohexanecarboxylic acid (Pictures in links below) dissolved in the organic solvent dichloromethane.
How would you seperate using liquid-liquid extraction?

I would say to use 3m of Hcl to seperate out the base (Benzamide) which would get the amino group protonated and leave the (acid) the same.

If this is right, what could I do to get the Benzamide back into its orginal form? Also, what would form the aqeuous layer and would would be the organic layer and why? What numerical evidence can be given to support your claim?

http://www.rdchemicals.com/chemicals.php… -
the 4 methylcyclohexanecarboxylic acid
https://secure.wikimedia.org/wikipedia/e…

What determines whether a the organic layer was upper or lower?

 

I know that this is long, but I really need to understand this!

[argulor]

You're kind of on the right track here, but let's go back to step one. So you want to separate the benzamide from the acid, let's start with the acid. What are some properties of acid base reactions? Ie, what would happen if you added the HCl like you say and what would happened if we added a strong base instead, NaOH?

[Vidya]

if you add HCl then benzamide  reacts and forms a chloride salt which is soluble in water .So aqueous layer has the benzamide
If you add NaOH then acid reacts to form sodium salt which is soluble in aqueous layer.You can compare densities of the compounds  to know which one is at the bottom and which one at the top.

[mrmedic]

Oh I think I get this 

Ok, the only problem I'm having then is the bit where it goes: "What numerical evidence can be given to support your claim?" 

I honestly don't understand this.

But thank you both for help with the first bit!

[fledarmus]

Check the pKa's of your compounds. Do you really think you will be able to pull a proton from benzamide using hydrochloric acid in water?