ACID - BASE TITRATION
Name of the student : Duru Aksoy
Name of the instructor: Serenay Tarhan Güler
Criteria to be evaluated: DCP and CE
The purpose of this investigation is to determine the concentration of an hydrochloric acid (HCl) solution by titrating it with sodium hydroxide (NaOH) solution of accurately known concentration. Titration is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte.¹ Titrant means substance with known concentration existing in buret, analyte means substance with unknown concentration in erlenmayer and indicator means chemical which is used to observe acid-base reaction.² In this investigation, titrant is NaOH, analyte is HCl and indicator is phenolphtalein.
Figure 1: Setup for a typical titration³
The average molarity of hydrochloric acid which was used in this experiment is 0.4 M and the molarity of sodium hydroxide is 1.0 M. It is important to know that this experiment was carried out in four trials and results’ mean was calculated in order to minimize errors. References
1. The Century Dictionary and Cyclopedia
2. Chemistry notebook
Apparatus and Materials
The apparatus consisted of a thermometer, 0.4M sodium hydroxide, hydrochloric acid, a buret, an erlenmayer, pure water for cleaning, and a graduated cylinder.
1. Obtain a buret. Clean the buret with pure water and rinse it. Then, pour 25 ml of hydrochloric acid into the buret. 2. Obtain an erlenmayer. Clean the erlenmayer with pure water and rinse it. Pour 50 ml of sodium hydroxide into the erlenmayer. 3. Add 3 drops of phenolphthalein(indicator) to the erlenmayer containing sodium hydroxide. 4. Start titrating the titrant with the analyte by holding the neck of the erlenmayer and mixing the solution continously. Always check the color of the...
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