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Unformatted text preview: Laura Lanier Lab L2 –Exp 9 November 5, 2009 D iscussion / Conclusion Testing common household items’ pH was more accurate and precise with the pH paper; there was no reference provided with the universal indicator, so only colors could be recorded, yielding no quantitative data. The colors can be used to rank the items’ strength, though, as the colors can be compared against each other and used in association with the pH from the pH paper. The measured pH for bleach was clearly wrong as it was measured to be 7 when literature says it should be in the range of 12 – 13; this error could have been caused by not enough solution being present to accurately test the pH. The pH of the baking soda may also have error as the solution was most likely not 1% wt/vol as no measurements were made while making the solution. The strong acid was hydrochloric acid while the weak acid was acetic acid, which is valid as these are the expected results; although these are expected, the percent dissociation of hydrochloric acid appears to have error as strong acids are supposed to completely dissociate while HCl’s calculated percent dissociate was only 57.5%. The strong base was sodium hydroxide while the weak base was ammonium hydroxide, which is valid as these are also the expected values as hydroxide is a very strong base, Na + is neutral and NH 4 is slightly acidic, making the ammonium hydroxide solution less basic. The results from this experiment appear to be valid as most of the data follows what was expected; the pH of the acids increases as the solutions are diluted while the pH of the bases decreases as the solutions are diluted. The percent dissociation of the acids and bases increases with dilution, with the exception of hydrochloric acid. The reason for the fluctuation of its dilution, with the exception of hydrochloric acid....
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