2. Why is it necessary to rinse the burette with a few mililitres of the sodium hydroxide solution used in the titration before filling it with this solution? It is necessary to rinse the burette with a few militres of the sodium hydroxide solution used in the titration before filling it with this solution becuase any tiny amounts of liquid remaining are the same as the solution used to fill the burette, so they will not change the concentration of the solution in any way. Moreover this process helps to prevent contamination from the remaining traces of water. 4. When using phenolpthalein indicator in a titration, why is it necessary to have the sodium hydroxide solution in the burette, rather than in the Erlenmeyer flask? When using phenolpthalein indicator in a titration, It is necessary to have the sodium hydroxide solution in the burette, rather than in the erlenmeyer flask becuase it is easy to observe the color change from colorless to pink. On the other hand, if HCI is taken in a burette and NaOH solution is in an erlenmeyer flask, it can be difficult to detect the color change from pink to colorless.

2. Why is it necessary to rinse the burette with a few mililitres of the sodium hydroxide solution used in the titration before filling it with this solution? It is necessary to rinse the burette with a few militres of the sodium hydroxide solution used in the titration before filling it with this solution becuase any tiny amounts of liquid remaining are the same as the solution used to fill the burette, so they will not change the concentration of the solution in any way. Moreover this process helps to prevent contamination from the remaining traces of water. 4. When using phenolpthalein indicator in a titration, why is it necessary to have the sodium hydroxide solution in the burette, rather than in the Erlenmeyer flask? When using phenolpthalein indicator in a titration, It is necessary to have the sodium hydroxide solution in the burette, rather than in the erlenmeyer flask becuase it is easy to observe the color change from colorless to pink. On the other hand, if HCI is taken in a burette and NaOH solution is in an erlenmeyer flask, it can be difficult to detect the color change from pink to colorless.

World of Chemistry, 3rd edition

3rd Edition

ISBN:9781133109655

Author:Steven S. Zumdahl, Susan L. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan L. Zumdahl, Donald J. DeCoste

Chapter15: Solutions

Section: Chapter Questions

Problem 63A

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