# Acid concentration



## Scdc5515 (Nov 3, 2021)

Can anybody tell me how to determine the concentration of the nitric acid that I’ve been producing? I use calcium ammonium nitrate with sulfuric acid and water and distill it. The process is supposed to yield a 68% concentration. The byproduct is simple gypsum which can be washed down the drain. I know there’s some type of math calculation by volume or weight but I don’t know how to do that. I thought using a hydrometer in a given amount of 68% nitric acid that I bought from the store and compared that to what I made. There’s a small difference but I don’t know what the difference in percentage is just by reading the hydrometer.


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## jadedalex (Nov 4, 2021)

Depends on how exact a reading you need. Check the Laboratory Supply companies. Maybe there is a test kit available...


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## Elemental (Nov 30, 2021)

The simple method would be to do a titration with a known amount of sodium hydroxide and an indicator (i.e. phenolphthalein). YouTube has plenty of videos to teach titrations. It’s a common general chemistry lab for students. Let me know if you have any questions about it.


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## Lino1406 (Nov 30, 2021)

Simpler, check density with areometer or weighing a known volume. Compare result with HNO3 density tables


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## Elemental (Nov 30, 2021)

Lino1406, 

Something like this? Alla France™ Nitric/Sulfuric Acid Hydrometer - Hydrometers Moisture Meters

Elemental


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## Lino1406 (Nov 30, 2021)

Positive, hydrometer also called areometer, densimeter...


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## Geo (Dec 1, 2021)

You can concentrate nitric acid with fractional distillation. It uses your distillation flask and a fractional distillation column. The column allows water to evaporate out of the flask where the nitric acid is condensed and returned to the flask.


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