Name: Jocelyne Munguia|Date: 6/12/13|
Exp 1: Observations of Chemical Changes|Lab Section: 75426|
|Chemicals|Well No.|Observations of the Reaction|
A.|NaHCO3 + HCl|A2|Tiny bubbles formed around the edges. Under white paper it looked transparent, but under black paper there was some white in the middle. | B.|HCl + BTB|A3|The mixture turned yellow instantly. Under white paper the mixture was more of mustard yellow and under black paper it was less of a bright yellow. | C.|NH3 + BTB|A4|The mixture is a lighter royal blue under white paper and a darker royal blue under black paper. The mustard yellow would be an acidic indicator and the royal blue a basic indicator. | D.|HCl + blue dye|A5|The mixture also turned green instantly. Under white paper it is a nice emerald color and slightly darker under black paper. | E.|Blue dye + NaOCl|A6|The mixture is fairly similar to NH3+BTB. It’s a little lighter under white paper, but about the same under black paper. | | with the 1 drop of HCl||After adding HCl the mixture turned into a forest green. But under white paper the edges were a turquoise color while the middle was still blue/green. Under black paper and good lighting the blue stood out more.| F.|NaOCl + KI|A7|The mixture remained a clear color. No significant change after adding starch and under black and white paper. | | with 1 drop of starch||After a while the clear color fogged a bit but not significantly. | G.|KI + Pb(NO3)2|A8|A thick bright yellow gradually took over the mixture. Under white paper the mixture appears thick almost yolk like. Under black paper you can see the color pop from the rest of the mixtures. Became a precipitate. | H.|NaOH + phenolphthalein|A9|The NaOH was clear, but as soon as it was dropped into the well it turned a very light pink and after mixing it with phenolphthalein it turned into a strong sort of fuchsia pink. It looks about the same under black and white paper. | I.|HCl + phenolphthalein|A10|The mixture instantly turned a cloudy white color, more uniform under white paper and foggy under black paper. | J.|NaOH + AgNO3|A11|The mixture turned into a thick brownish green color. Under white paper more of a wet sand color and a little lighter under black paper. Turned into precipitate after some time. | K.|AgNO3 + NH3|A12|The mixture was a cloudy white that under black paper was not evenly distributed. | |after exposure to bright light||After about 10 min of exposing the paper under a light bulb. Slowly a dark yellow brown color appeared and gradually got a little darker. | L.|NH3 and CuSO4|B1|The mixture turned a cloudy light blue. Under black and white paper you can see a swirlish color of blue and seemed to be pretty thick as well. | Part F: Testing of Various Foods with the NaOCl + KI solution
Foods|Presence or Absence of Starch|
Apple |The apple did not produce a dark pigment but turned a more yellowish brown tone. | Bread |Turned a dark brownish pigment so It tested to contained starch. | Tuna |The tuna did not change significantly and did not show presence of starch. | Sharp cheddar cheese |The cheese didn’t seem to change significantly and did not show presence of starch | Potato |The potato turned a dark brown pigment and showed presence of starch. | ||
Household Chemicals with Bromthymol Blue
Use the empty pipet in the Auxiliary Supplies Bag to test several (at least 3) household items including household cleaning products with bromothymol blue. Rinse the pipet well before using it on the next household chemical. When finished with this experiment rinse the pipet well and return it to the Auxiliary Bag for use in future experiments. Name the items tested and record their results.
Household Chemicals|Well No.|Observations of the Reaction|
All purpose rust,lime, and calcium cleaner |B2|The chemical was a clearish color and turned a light yellow after adding the bromothymol blue into the mixture. | Pine sol |B3|The pine sol is a light...
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