29.47 ml of a solution of the acid hbr is titrated, and 72.90 ml of 0.2500-m naoh is required to reach the equivalence point. calculate the original concentration of the acid solution.

The original concentration of the acid solution is 6.175 10^-4 mol / L.

Explanation:

Concentration is the ratio of solute in a solution to either solvent or total solution. It is expressed in terms of mass per unit volume

                        HBr + NaOH -----> NaBr + H2O

There is a 1:1 equivalence with acid and base.

Moles of NaOH = 72.90 10^-3 0.25

                          = 0.0182 mol.

[ HBr ] = moles of base / volume of a solution

          = 0.0182 / 29.47

          = 6.175 10^-4 mol / L.

it's c (engineer's do their work with mechanical stuff not on any living being)