Question

When the concentration of hydronium ions equals the concentration of hydroxide ions, it is called the _____.

Answer 1

When the concentration of H₃O⁺ becomes equal to the concentration of OH⁻ ions, it is called the Neutral Solution.

Example:
              A neutral water with pH 7 contains Hydronium and Hydroxyl ions in following number,

                      [H₃O⁺]  =  1.0 × 10⁻⁷ M

                      [OH⁻]   =  1.0 × 10⁻⁷ M

Answer 2

It is called the EQUAVALENCE POINT. It is the titration!

Had a test and this was therefore the correct answer.

Hope this helped. :)