Measuring The Concentration Of Unknown Substances

1005 Words Nov 1st, 2016 5 Pages
Measuring Molarity by Two Different Titration
Authors: Seungchan Lee, Emily Lemchuk, Le, Linh, Jacob Lawhorn, Francis Esuon, Dr. Breece, CHM 144 D, 2016-11-02
Introduction:
The significance of titration is to find out the concentration of unknown substances. There are different kinds of titration and this experiment consists of two kinds of titration. The traditional titration uses the phenolphthalein indicator dye to determine the concentration by color change. The modern titration uses pH electrodes. The chemical reaction “H3C6H6O7(aq)+3OH-(aq)→3H2O(l)+C6H5O7(aq)” is used to determine the moles of citric acid from the moles of NaOH. The main scientific objective of the experiment is to determine the molarity of two different sodas by traditional titration and modern titration respectively.
Methods:
-Traditional method with the use of phenolphthalein indicator dye
A ring stand with the buret was set up, and then a large waste beaker was placed under the buret. The buret was rinsed with distilled water. A clean 150mL beaker was used to obtain approximately 100mL of 0.0474 M NaOH solution. The buret was rinsed by sodium hydroxide. The buret was filled with sodium hydroxide by a clean funnel. The funnel was removed, and the stopcock was opened for a short time. The level of the solution was lowered. The leaking was checked, and then the initial volume of sodium hydroxide solution was recorded. The carbonic acid in the soda was previously removed by boiling. Prior to each…
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