Concentration of nitric acid

[ronmoper76]

Does anyone know how to determine the exact concentration of a nitric acid solution that's not to difficult. I have a jug that I distilled last year and I'm trying to get it from fuming red to 70%. I assume it's in the high 90's but I could be wrong,can I weigh so many milliliters of it to come up with what concentration I have to know how much to dilute it?

[SeaMonkey]

You could water it down to a lower percentage then re-distill it to obtain the desired azeotrope.

 

Yes you can weigh a specific volume to determine its strength.

 

Another useful tool.

 

NurdRage on YouTube has several very useful videos on how to deal with Nitric Acid.

Edited August 11, 2021 by SeaMonkey

[MadMat]

Have you found a table that converts specific gravity to % for nitric acid or were you going to calculate it out? You could possibly buy a hydrometer from a place like American Science and Surplus for pretty cheap and determine the specific gravity that way. It would probably be more accurate than weighing out a volume of the solution, unless you have a very accurate and precise scale and a pipette for measuring the specific volume solution. So, if the final concentration is critical I would probably go the hyrometer route

Edited August 11, 2021 by MadMat

[Arthur]

I'd certainly look at buying a hydrometer in the right range and searching www for tables of concentration vs sg for nitric acid. Then check what sg you have and dilute it incrementally to the sg/concentration that you want.

 

https://www.handymath.com/cgi-bin/nitrictble2.cgi?submit=Entry just as one option.

[MadMat]

I'd certainly look at buying a hydrometer in the right range and searching www for tables of concentration vs sg for nitric acid. Then check what sg you have and dilute it incrementally to the sg/concentration that you want.

 

https://www.handymath.com/cgi-bin/nitrictble2.cgi?submit=Entry just as one option.

Yeah, I forgot to mention that hydrometers come calibrated in different ranges and you have to get one that is within your desired range of specific gravity. Nice catch Art

Edited August 11, 2021 by MadMat

[MadMat]

Here is a start for you: https://materials.gelsonluz.com/2019/06/density-of-nitric-acid.html

[sefrez]

You only need a decent scale. Get, ideally, a tall / narrow tube (perhaps a graduated cylinder) and fill it too some level with purified water. Mark this arbitrary level with a marker / piece of tape / (what ever allows you to consistently fill to the same level; you can estimate your introduced error here.) Measure the weight of the added water at the temperature the density tables are given in and look at the density of water at that temperature as well. From that you know your volume at this level with error coming primarily from your scale. Empty (make dry) the tube and fill to the same level with your nitric. A new error on your part is introduced with the repeatability of filling to the same level as before. This error can be reduced by working with taller / narrower tubes at same or larger theoretical volume. Measure this weight and divide it by the volume determined before. Compare against a nitric acid concentration vs density chart. If you know your scale introduced errors and the errors from data provided on the web (probably less than your scale) then you should be able to get a conc. +/- uncertainty range.