Observations of Chemical Changes
Abstract: The purposes of this lab is to observe the reactions of some common chemicals contained in consumer products and observe the macroscopic changes these chemicals undergo. Purpose: The purpose of the lab is to be able to interpret underlying macroscopic changes in terms of the behavior of atoms and molecules and also to learn how to separate mixtures into their component substances by solubility. Procedures/Materials Needed:
1 Sheet of white and dark paper
1 Paper towel
1 Distilled water
1 Small amounts of household cleaning products
1 Pipet, Empty Short Stem
1 Aqueous Ammonia, 1M -1mL
1 Bromthymol Blue, 0.04% - 2 mL in Pipet
1 Copper (II) Sulfate, 0.2 M – 2 mL in Pipet
1 FDC Blue Dye #-1.0.1% - 2 mL in Pipet
1 Hydrochloric Acid, 1.0M-1 mL
1 Lead (II) Nitrate, 0.2 M- 2 mL in Pipet
1 Potassium Iodide, 0.1 M-2 mL in Pipet
1 Silver Nitrate, 0.1 N – 2 mL in white Dropper Bottle
1 Sodium Bicarbonate, 1 M – 2 mL in Pipet
1 Sodium Hydroxide, 1 M – 1 mL
1 Sodium Hypochlorite, 1% - 2 mL in Pipet
1 Starch Solution, 1% Stabilized - 2 mL in Pipet
1. For the following combinations of chemicals and using a different well of the 96-well plate for each combination, place 2 pipet drops of the first in one well and add 2 drops of the second chemical. Next observe the mixtures against the white and dark backgrounds by slipping white and black paper underneath the well plate. For each reaction record the well number of the mixture and your observations. a. Sodium Bicarbonate and Hydrochloric Acid
b. Hydrochloric Acid and Bromothymol Blue
c. Ammonia and Bromothymol Blue
d. Hydrochloric Acid and Blue Dye
e. Blue Dye and Sodium Hypochlorite
f. Potassium Iodide and Lead Nitrate
g. Sodium Hydroxide and Phenolphthalein
h. Hydrochloric Acid and Phenolphthalein
i. Sodium Hydroxide and Silver Nitrate
j. Silver Nitrate and Ammonia
k. Ammonia and Copper Sulfate
Data and Observations:
Data Table 1: Reactions
Sodium Bicarbonate and Hydrochloric Acid
Hydrochloric Acid and Bromothymol Blue
Clear with Bubbles
Clear with a tint of orange
Ammonia and Bromothymol Blue
Hydrochloric Acid and Blue Dye
Emerald Green with a teal layer on top
Blue Dye and Sodium Hypochlorite
Potassium Iodide and Lead Nitrate
Went from dark blue, turned green then yellow.
Yellow milky color/ Nitrate and Potassium
Sodium Hydroxide and Phenolphthalein
Hydrochloric Acid and Phenolphthalein
Hot pink color
Sodium Hydroxide and Silver Nitrate
Silver Nitrate and Ammonia
Ammonia and Copper Sulfate
Hint of pink when silver added looks like brown mud
Sediment layer baby blue with dark layer on top.
A. Suppose a household product label says it contains sodium hydrogen carbonate (sodium bicarbonate). How would you test this material for the presence of sodium bicarbonate?
You would mix it with HCI and observe it for bubbles.
B. You know what color phenolphthalein and Bromothymol blue turn when testing an acid or a base. Use the empty pipet in the Auxiliary Supplies Bag to test several household items including household cleaning products with Bromothymol. Name the items tested and record their results. What do these results mean?
Bleach with Bromothymol Blue – Yellow and blue layer/ it separates the acid and the base.
Hand Soap with Bromothymol Blue – Turned yellow which means it’s an acid.
Ammonia with Bromothymol Blue – Dark blue which means it’s a base.
C. You found a sample of a solution that has a faint odor of vinegar. You are verifying that is indeed vinegar and you add a few drops of phenolphthalein. The...
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