How can Brandon rescue the titration without starting over?

Question

Brandon is attempting to standardize a NaOH solution, that is approximately 0.05 M, against 0.145 grams of sulfamic acid. At around 33 ml NaOH titrant he realizes that he forgot to add the indicator. When he does add it, the flask turns bright pink. How can Brandon rescue the titration without starting over? Be specific in regards to what he should do at the bench and in the calculations.

Answer 1

He can add a measured amount of the sulfamic acid turning the solution back to clear and then continue the titration by carefully adding the NaOH solution until the endpoint. [This is called doing a 'back titration'.]