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Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: zuriel on January 28, 2015, 01:14:33 PM

Title: Can you make fuming nitric acid from 65% HNO3 and conc. sulphuric?
Post by: zuriel on January 28, 2015, 01:14:33 PM

Hi Folks,

I want to do a nitration but have no fuming nitric at the moment. Someone told me that if I mix equal volumes of nitric 65% and conc. sulphuric that it should do the job but I'm a bit sceptical. I can get more fuming soon but don't want to wait the while.

Can anyone offer any advice?

Thanks!

Title: Re: Can you make fuming nitric acid from 65% HNO3 and conc. sulphuric?
Post by: phth on January 28, 2015, 01:29:47 PM

boiling point should should work unless you chose an azeotropic mixture.  How can you extract nitric acid from a azeotropic mixture?

Title: Re: Can you make fuming nitric acid from 65% HNO3 and conc. sulphuric?
Post by: zuriel on January 28, 2015, 01:31:44 PM

Sorry phth I'm not sure I understand your suggestion.

Title: Re: Can you make fuming nitric acid from 65% HNO3 and conc. sulphuric?
Post by: TheUnassuming on January 28, 2015, 02:59:44 PM

Not sure of your substrate, but its a standard for undergrad o-chem labs to use HNO3 and H2SO4 to nitrate a benzyl ring.  Check out the wiki page on nitration for links to orgsyn papers that will give you a good starting point.

Title: Re: Can you make fuming nitric acid from 65% HNO3 and conc. sulphuric?
Post by: zuriel on January 28, 2015, 03:25:19 PM

Thanks for the tip!  :)

Title: Re: Can you make fuming nitric acid from 65% HNO3 and conc. sulphuric?
Post by: phth on January 28, 2015, 03:34:13 PM

I am saying that HNO₃ is the lowest boiling point.  Therefore it can be distilled to purify, and furthermore titrated.  IF you're serious about being a chemist you have to teach yourself about azeotropic distillations, the sooner the better.

Title: Re: Can you make fuming nitric acid from 65% HNO3 and conc. sulphuric?
Post by: zuriel on January 28, 2015, 07:45:20 PM

I'm going to try the method that employs 1:1 mix of 65% nitric and conc. sulphuric for now at least.

I'd be interested in synthesising a poly nitrated phenyl acetic acid too (both meta and para positions) and I found a really old journal that makes it by just refluxing phenyl acetic acid in fuming nitric - I wonder would this work for the sulphuric/nitric mix.

Azeotropic distillation - although it seems a viable option - is totally impractical to me for now. Plus I still have MANY years to go before I'd ever consider myself a very serious chemist lol.

Thanks all for answers/suggestions.