[bobopel]

How to calculate the cocentration of NHO3( nitric acid)
How to calculate the concentration of any compound , mixture or any élément? Which formula to use for ?

[Unknown008]

Concentration of substances is measured in mol/dm^3 (at least, in my country, I don't know if it's different in the other countries, but I'll stick to it.)

Ah, nitric acid is HNO3, I guess you made a slight mistake up there. For calculating concentration in my school problems, I do titration. Using the proper equation and reactants, I can find the concentration of nearly any substance, provided that I am given the concentration of the reactant I choose for the experiment.

For example, I have a 0.1mol/dm^3 aqueous solution of NaOH (sodium hydroxide). I titrate. Lets say that I used 25.0cm^3 of HNO3 to neutralise 25.0cm^3 of NaOH.

Using,

HNO3 + NaOH --> NaNO3 + H2O

I know that one mole of HNO3 will react with one mole of NaOH. By these values, I can easily find the concentration of the HNO3.

Hoped it helped. If you need more explanation, post and say where you can't understand very much.

[malb]

concentration is calculated using this formula

n=cv
then you rearrange to get c
you need more info than just HNO3 to calaculate it

number of mol and volume
hope this equation helps

malb