How to find the concentration of nitric acid by volumetric titration?

dear sir
Commercially I am buying the acids and sub boiling the acids at 70 degrees. So I need to know how much concentration would be there after sub boiling, I need a method of finding the concentration.

Thank you

For some reason, just a gut feeling I guess, I doubt if you will get a significant concentration by sub boiling, unless you cook it for a very long time.
Find a school chemistry teacher to help you get started. If the acid has any metal at all dissolved in it, you need to use a 0.5N sodium hydroxide ⇦ on eBay or Amazon [affil link] or 0.1N ⇦ on eBay or Amazon [affil link] titrant with strong agitation and a slow addition or you will use some of the titrant in dropping out the metal as a metal hydroxide. It is very slow to redissolve. You should also use an indicator such as methyl red ⇦ on eBay & Amazon [affil link] or methyl orange ⇦ on eBay or Amazon [affil link] . phenolphthalein will cause a problem. If there is zero metal, then it does not matter very much what strength titrant or indicator that you use. Note, you do need to dilute your acid sample with about 100 ml of distilled water. Add the acid to the water.