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.

Answer 2

The indicator which is used for the titration between 0.10 M HCOOH and 0.10 M of NaOH is $\boxed{{\text{phenolphthalein}}}$.

Further explanation:

The titration is method that used to carrying out the reaction between two solutions to determine the concentration of the unknown solution. For acid-base reaction, titration is helpful in order to calculate the pH at various point during the reaction.

The titration of weak acid and strong base occur via a transfer of proton from the weak acid to   ion. At complete neutralization of acid the point is known as the equivalence point. The pH occurs at the equivalence point of the weak acid and strong base titration is slightly greater than 7 because all the weak acid has been converted to its conjugate base. This conjugate base can react with water and produce hydroxide ion in the solution.

${{\text{A}}^-}+{{\text{H}}_{\text{2}}}{\text{O}}\rightleftharpoons{\text{AH}}+{\text{O}}{{\text{H}}^-}$

The given solution in the question is a mixture of a weak acid, HCOOH and strong base, NaOH. Since titration of a weak acid and strong solution gives pH greater than 7 thus the indicator that can be employed in this titration is phenolphthalein which has pH range from 8 to 10.

Learn more:

1. Determine the lewis structure of butanal.: brainly.com/question/6215269

2. Complete equation for the dissociation of ${\text{N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}$(aq): brainly.com/question/5425813

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Titrations

Keywords: pH, solution of HCOOH acid, NaOH, titration, weak acid, strong base, pOH, equilibrium, strong acid, weak base and phenolphthalein.