Standardization of Sodium Hydroxide
Titration is a common laboratory method of quantitative chemical analysis. It is used to determine the unknown concentration of an analyte. Chemists typically use titrations in quality control methods and laboratory methods designed for acid/bases and redox.
In this laboratory experiment, your students will use a Vernier drop counter to standardize a sample of sodium hydroxide against potassium hydrogen phthalate (KHP). Standardization must be accomplished before a base can be used in any titration (therefore, this laboratory experiment is suggested to be one of the first experiments to incorporate when learning a titration). Phenolphthalein will be used as an indicator for the titration. After the proper amount of sodium hydroxide is added, the hydrochloric acid concentration (in molarity) will be determined.
PRODUCT INFO
This U-PIK will include enough materials for eight student groups. Suggested group size is 3-4 students. The U-PIK will include the following:
- 8 LabQuest 2 interfaces
- 8 Drop Counters
- Potassium Hydrogen Phthalate (KHP)
- 8 Stir plates with magnets
- 4 Top-Loading Balances
- 8 125-mL Erlenmeyer flasks
- Sodium hydroxide solution
- Phenolphthalein indicator
WHEN TO INTEGRATE?
The titration can be easily be introduced after discussing acid and base theory. This technique is one of the most common laboratory methods of quantitative chemical analysis that is used to determine the unknown concentration of a titrant before use (especially if the titrant is a base).
Students will be required to use the amount of KHP and the volume of NaOH to calculate the actual molarity of the solution. Therefore a previous discussion of volume and the molarity equation is recommended.
Drop Counter Manual
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