# 67% vs. 70% Nitric Acid



## Finmad (Dec 29, 2021)

I have been refining for about 12 months using Nitric at 70%. I found a local supplier with 67% at a good price. Is there any reason why I could not use 67%? It may be a stupid question, but with chemistry, sometimes the logical obvious is wrong....


----------



## Elemental (Dec 29, 2021)

The 67% will work fine for refining.


----------



## Finmad (Dec 30, 2021)

Elemental said:


> The 67% will work fine for refining.


Excellent, thank you


----------



## Martijn (Jan 1, 2022)

I think they are both at the azeotrope of 68%
The first supplier may have just rounded off the number, and the second one may be one the conservative side to be sure. 
I could be wrong but that little difference won't matter much. 
I use 50% HNO3 +/-  Works fine and is often diluted more in the processes it's used in.


----------

