Question

how to find concentration of a solution?

Answer 1

by a ph paper you can find the concentration of H+
ions

Answer 2

Once you've found the moles of solute, you can simply divide by the volume of solution in the flask to find the molarity of thesolution, or convert moles to grams and divide by the volume of the solution to find theconcentration in g/L. This will require a basic understanding of Stoichiometry.
concentration =mass / volume