The Vespiary

The Hive => Newbee Forum => Topic started by: abuse on October 30, 2003, 08:14:00 PM

Title: Interesting info on p-benzo from hydroquinone...
Post by: abuse on October 30, 2003, 08:14:00 PM

I found some information on Photo chemistry regarding hydroquinone. Follow the link below and scroll down about one page to the heading Developer Alkalis.

http://www.ruger.demon.co.uk/HTMLReal/Photography/Chemistry/Chem1.html (http://www.ruger.demon.co.uk/HTMLReal/Photography/Chemistry/Chem1.html)

The author mentions that it is possible to react hydroquinone with an alkali, such as sodium hydroxide or pottasium hydroxide, to ionize the hydrogens on the hydroxyl groups of hydroquinone. The reaction diagram depicts something that looks just like benzoquinone as the product from this reaction. I'm no chemist, but I thought it was interesting anyway.

Common sense tells me that it's probably not that easy to create benzoquinone from hydroquinone by using an alkali.

Anyone?

Title: Sorry, that's not benzoquinone...
Post by: Ziqquratu on October 30, 2003, 08:30:00 PM

Sorry, that's not benzoquinone... it's the disodum salt of hydroquinone.  If it were benzoquinone, it would have no charge and a double bond to each of the O's - this is charged on both O's, and there is only one bond to each.

What happens when you react hydroquinone with a strong base is the hydro acts as an acid - the H's from the OH groups leave and react with the OH^- from the base... then the salt forms between the hydroquinone ion and the Na⁺ or K⁺ or whatever from the base.  Simple acid-base reaction.

[edit] If you scroll a tiny bit down the page, to the very next diagram, there's a picture of benzoquinone as "oxidised Hydroquinone".  Have a look, the differences become fairly obvious

Title: But...
Post by: ning on November 03, 2003, 01:58:00 PM

Supposedly it's very easy (too damn easy) to oxidize hydroquinone, specially in basic or acid solution.

Ning has a paper where they put some copper salts in alkaline solution and bubble air thru it. That's enough, apparently.

Ugh. Ning fears for the methylation....ugh.

Title: Refs
Post by: moo on November 03, 2003, 04:21:00 PM

Ning: You often say that you have a reference or a paper on something interesting. In future, could you try to share the references instead of only telling they exist, please? Not the whole articles necessarily, the references are all that is needed to have a positive surprise at the library or whereever. The more information is available through TFSE the better. Thanks!