Sciencemadness Discussion Board

Benzene from Sodium Benzoate and Sodium Hydroxide equation balance

zenosx - 18-2-2013 at 20:39

First off, while I most certainly have UTFSE and other resources here, I apologize if this is a very easily found question. I was trying to figure it out for myself rather than just copy others work, to some extent that is. Anyway...

While this is a fairly straightforward and well documented workup, I am curious if the chemical equations I worked out in the photo are correct. I tried my own ideas, which obviously didn't equate to real chemistry, then used various tools + intellect (sparse as it is) to come up with the lower one.

for those not wanting to click the photo it's

(hell I should have just wrote this I guess)

12 NaOH + 18 Na C6H5CO2 = 24 CO2 + 17 C6H6 + 30 Na
Secondary:
2 CO2 + Na = NaCO3 + CO

Off-gassing will be CO2 and CO + Benzene and Sodium Carbonate, however Sodium Carbonate is Na2CO3 so I am missing something here.

ANY input is great. Thanks from a new to the scene organic chemist.

Benzene (For Web).jpg - 189kB

[Edited on 19-2-2013 by zenosx]

Magpie - 18-2-2013 at 21:16

C6H5COONa + NaOH + heat ---> Na2CO3 + C6H6

I have done this reaction using my old school (Brewster) procedure.

It's hard to get a good yield due to poor heat transfer through the solid reactants. My procedure specifies use of a large test tube (8") as reaction vessel. This helps get the heat where it's needed. A rubber stopper with glass tube is used to lead the benzene gas to a condenser.

There's a member publication on this in the forum library.

[Edited on 19-2-2013 by Magpie]

zenosx - 19-2-2013 at 20:39

Thanks. Yes, I am aware of the many write up's on this reaction, I was merely trying to balance the equation and kept coming up wrong as I knew Na2CO3 was a produced side product.

Thanks again!