The number of unknown acid was O, and 0.1 M NaOH was used to determine molarity of unknown acid. The first step was making an unknown acid solution. About 20 mL of deionized water and 3 drops of phenolphthalein indicator were added the 5 mL acid in a flask. And then 0.1 M NaOH in a buret was slowly put into the flask. The initial volume of NaOH of both trial 1 and 2 was 10.00 mL. While small volume of NaOH was added into flask, it was swirled to mix well. Addition of NaOH was slowly continued until the red color of phenolphthalein began to linger, indicating the endpoint was being approached. When the color of solution was completely turned to red, the addition of NaOH was stopped, and the final volume of NaOH was record. The final volume of trial 1 was 27.60 mL, and the trial was 27.70mL. After getting all values, the morality was calculated by the formula, Macid ´ Vacid = Mbase ´ Vbase, and the average molarity of the acid was 3.53 ´ 10 .
2006-12-05
00:50:31
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2 answers
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Woo In J
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