0 which can be measured by the pH electrode or the indicator dye that would

0 which can be measured by the ph electrode or the

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at the pH of 7.0, which can be measured by the pH electrode or the indicator dye that would turn the soda pink. Phenolphthalein is the indicator dye used in this experiment that changes the color to pink when the pH is 8.2-9.2. For citric acid the end point would be about 8.5, which is when enough base has been added to neutralize all of citric acid’s three acidic protons. Two different methods of titration are used in this experiment. The first method is with the phenolphthalein dye. For this method, the clear soda must be used, so the faint pink color will show. The soda and the dye are placed in the erlenmeyer flask and NaOH is placed in the buret. Once the titration gets to the end point the faint pink color will show after swirling. For the second method of titration, the pH is monitored by a pH electrode. The darker soda is used during this method because the color does not have to be seen visually.. A magnetic stir plate with a magnetic strip bar is used to mix the reaction while the pH electrode measures the pH. Methods First method: indicator dye- The first method of titration was done with a phenolphthalein indicator. First, the buret was cleaned by placing a plastic funnel at the top of the buret and and filling the buret with distilled water and draining it completely. This process was repeated two more times. After checking that the stopcock does not leak, 100 mL of sodium hydroxide was collected. Then, with the stopcock closed, the NaOH solution was added to the buret 5 mL at a time and then slowly dripped into the waste beaker. This process was then repeated two more times. Next, the buret was filled with NaOH to the 0.00 mL mark and the stopcock was turned quickly to release a small amount of the solution. The waste beaker was
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