Observations of Chemical Changes

1285 WordsJul 27, 20126 Pages
Data Tables: Part 1: Chemicals Well No. Observations of the Reaction A. NaHCO3 + HCl A1 Bubbles immediately formed and started popping (not rapidly). This could be seen more easily with the black paper underneath the well plate B. HCl + BTB C1 Once I added the Bromothymol Blue indicator, it turned an orange-like color C. NH3 + BTB E1 The reaction turned dark blue. When Bromothymol Blue reacts with an acid, it turned orange, and when it reacts with a base, the end result is blue. D. HCl + blue dye G1 The reaction turned green. E. Blue dye + NaOCl A3 The reaction turned blue. with the 1 drop of HCl A3 The reaction turned from blue to a blotchy bowl of blue, green, and yellow. Similar to oil not mixing with water, the…show more content…
Suppose a household product label says it contains sodium hydrogen carbonate (sodium bicarbonate, NaHCO3). How would you test this material for the presence of sodium bicarbonate? I would test this in the well plate to see if it would react as it did above. For instance, I could add HCl and see if it bubbles B. Looking at the household chemicals you tested with bromthymol blue, what can you deduce from the test results for each of the household chemicals? In Data Table 1, I came to the conclusion that when Bromothymol Blue reacts with an acid, it turned orange, and when it reacts with a base, it turns a dark blue. Given this, I can deduce that both Windex and 409 are bases whereas Palmolive is an acid. Prior to this experiment, I would have thought the opposite to be true. C. You found a sample of a solution that you think might be vinegar which is acidic. You are verifying that it is indeed vinegar and you add a few drops of phenolphthalein. The sample turns pink. What does that tell you about this sample? We learned above that phenolphthalein only turns pink when it reacts with a base. Because vinegar is acidic, there’s no way the sample that was found is, in fact, vinegar given the pink reaction. D. You suspect dissolved silver ions in a solution. How would you test this solution to confirm the presence of the silver ions? I would add sodium hydroxide to the solution to see if it turned a thick brown color. If so, I would safely assume
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