AP Chemistry Per. 1-2
10/31/12
Titration Lab
Titrations are a very useful method of discovering the amount or concentration of unknown substances. The method is very well suited towards acid-base reactions. Titrations are often used in industry to analyze products to be sold. In this lab, standardizations will be done in the first two experiments and then titration analysis in the third.
Standardization of a base (NaOH) using a primary standard (KHP)
Standardization of an acid (HCL) with the standard base
Titration analysis of unknown acids and bases (antacid tablets)
Standardization of NaOH
Materials: -Buret -250 mL Erlenmeyer flask -0.1 M NaOH -0.8 g KHP -Water -Three 150 mL beakers -magnetic stirrer
A buret was rinsed with water and then with a small amount of the NaOH solution. Then the buret was filled with NaOH. The initial volume was read and recorded and the buret was labeled as BASE.
Then approximately 0.8 g of KHP was placed in the flask. 100 mL of water was added and was swirled until dissolved. Three drops of phenolphthalein indicator were then added.
The mixture was then placed on the magnetic stirrer and drops of the base solution (NaOH) were added through the buret until it turned a very faint pink. The final buret volume was then read and recorded.
Data | Trial 1 |Trial 2 | |Mass of KHP in flask |85.2 |84.8 | |Initial buret reading |48mL |50mL | |Final buret reading |18.5mL |18.4mL | |Volume of NaOH required to neutralized the KHP |30.5mL |31.6mL | |
Calculations:
II. Standardization of HCL solution
Materials: -Buret -250 mL Erlenmeyer flask -0.1 M HCL -0.1 M NaOH -Water -Three 150 mL beakers -magnetic stirrer
50mL of 0.1 M HCL was obtained in a beaker. A second buret was rinsed with water and then a small amount of HCL, and then filled with HCL. It was then labeled ACID. The initial volume was recorded and then approximately