How concentration of nitric acid can find?

Answer 1

I suggest you look up titrations. It's a type of chemical procedure meant to accurately measure the concentration of an unknown concentration of a specific chemical. They're mainly meant for acid base reactions, so you're fine; I think there's also a procedure for redox reactions.

They require some rather specialized equipment, and anywhere you can find that equipment, you should also be able to find a chemist (even a high school chemistry teacher) who is familiar with the procedure, which is far too complicated for me to describe without diagrams. It's a very precise method, too - my father used it as a major part of doctorate study, and even first year undergraduate students are expected to be able to produce small errors in very precise data - I had a chem lab where we measured concentration to 0.0001 M, and lost 5% of the lab mark for every 0.0001 M off what the prepared sample was.