Observations of Chemical Changes

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Chem 181 DL1
Professor Snyder
Rebecca Hansen
Observations of Chemical Changes
9/10/12

Experiment: To examine the reactions of some common chemicals contained in Consumer products and observe the macroscopic changes these chemicals undergo. Examining reactions of common chemicals contained in consumer products. In this lab, it will show the macroscopic changed the chemicals undergo.

Objective: To observe some properties of chemical reactions and to associate chemical properties with household products.

Chemicals used in this lab were: Ammonia (NH3) Bromthymol Blue (BTB), Copper (II) Sulfate(CuSO4), FDC Blue Dye #1, Hydrochloric acid (HCl), Lead (II) Nitrate(Pb(NO3)2), Phenolphtalein Solution- (C20H14O4 ), Potassium Iodide (Kl) Silver Nitrate(AgNO3), Sodium Bicarbonate(NaHCO3), Sodium Hydroxide (NaOH), Sodium Hypochlorite(NaClO), Starch Solution. Also used for this experiment were house hold items.

Exp. Procedure: The procedure was to combine the chemicals using the 96 well-plate for each combination. 2 Pipet drops of the first chemical in one well and then adding 2 drops of the second chemical. Some of the combinations had asked for 3 chemicals and not 2 drops for everyone. Also needed were, a piece of white paper, a piece of black paper, and the chemicals from the Observation of Chemical Changes Experiment Bag. For ever reaction, I wrote down the chemical combination, the well number, and my observations of the reactions against the white and dark backgrounds.

Well#/Question| Chemicals| Reaction|
A1/A| NaHCO3 & HCl - CO2| The reaction with these chemicals, I had seen small white bubbles, both background white and black shows the same type of change.| | |
|
B1/B| HCl & BTB| For this reaction, it had turned yellow. | | On white paper is was bright, | | |
On black paper it was mustard looking/ yellow.|
|
C1/C| NH3 & BTB| These two chemicals it had turned a very light blue on the white paper. On the black paper it looked dark blue, there was no actual chemical change.| |
|
D1/D| HCl & BTB| After mixing these two chemicals, it had turned green. It stayed green on the white paper, and when| brought to the black paper, it looked black.| |
There was a color change with these chemicals.|
|
E1/E| Blue dye & NaOCl (1 drop of HCl)| After mixing the two first chemicals, It has turned dark blue on the white and black on the black. After the 1 drop of HCl, on both the white and black it turned dark green.| | | |

|
H5/F**| NaOCl & KI (1 drop of starch)| After adding the 2nd drop of KI, the mixture had turned copper for on the white and dark gold on the black, than 10 seconds after adding both, it turned yellow. After starch all black for white and black backgrounds.| G1/G| Kl & Pb(NO3)2| After this chemical reaction, it was yellow, milky and cloudy looking on both the white and black. It also had a thicker appearance.| A5/H| NaOH & phenolphtalein| After adding the 2nd chemical the color turned magenta, and clear looking on the white paper. On the black paper it was a deeper color, more close to a fuchsia.| C5/I| HCl & phenolphtalein| Nothing had happened with these reactions on the white. On the black it was slightly cloudy looking, clear still.| B10/J| NaOH & AgNO3| On the white background the reaction between the two had turned a brownish greenish color which also looked very muddy. The black background was the same, but more opaque.| D12/ K| AgNO3 & NH3| On the white background with these reactions it had turned a pearlish looking color. On the black it was white, but looked milkier. After exposure to bright light, there were small bubbles at the bottom (clear)| F12/L| NH3 & CuSO4| It was clear for a millisecond than it had turned a little blue, but it was very faint on the white. A little more pronounced on the black|

For the experiment for F, which I had added two...
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