Question

Which indicator would be the best to use for a titration between 0.10 m hcooh with 0.10 m naoh? you will probably need to consult the appropriate table in the book. 1. methyl red, color change at ph 3-5 2. alizarin yellow r, color change at ph 10-12 3. thymol blue, color change at ph 2-4 4. bromothymol blue, color change at ph 6-8 5. phenolphthalein, color change at ph 8-10?

Answer 1

After looking at the table I believe the answer is 5. phenolphthalein, color change at pH 8-10. Phenolphthalein is an organic compound used as an acid-base indicator. It is colorless in acid solutions and turns pink to red as the solution becomes alkaline. The compound is also medically used as a cathartic.