Acids, Bases, and pH Lab
In this lab the testing of whether or not a substance was an acid or a base occurred. Each substance was tested with the indicators red litmus paper, blue litmus paper, pH paper, phenolthalein, bromthymol blue, and phenol red. While the substances were tested the group noticed that the substances tested with the red and blue litmus paper, the phenolthatein, bronthmol blue were the easiest to interpret. The color changes that occurred when this indicator was put into a substance made it really obvious whether or not the substance was an acid or a base. Especially, the magenta color that the phenolthalein turned in the presence of a base really made the substance easy to interpret. In addition the indicators that were the most accurate were the pH paper and the phenalthalein. The phenalthalien was one of the most accurate indicators because the bright magenta pink color that a base substance turned was very prominent compared to the clear color that formed when the substance was an acid. The pH paper was the most accurate indicator because there was a color chart that showed specifically whether or not the substance was a base or an acid. The pH paper also got detailed enough to show whether or not the substance was pure/neutral or a strong base or acid. Furthermore, it was easy to tell that acids were 1-6 on the pH scale, water or neutral substances were 7, and bases were from 8- 14. The other indicators were not as accurate. The indicator phenol red always turned the substance either a yellow orange color or a red orange color, and that was sometimes a little difficult to figure out whether or not a substance was a base or an acid. The bronthymol blue did turn a yellow color in the presence of an acid, but sometimes the substance either turned a greenish color or had specks of blue in the substance. When the substance was tested in both the red and the blue litmus papers sometimes there were contradictory results, so the litmus paper...
Please join StudyMode to read the full document