By: Andre the Giant Higgson
CHE 107 E1
Intro to Chemistry 1
Certain Chemicals like Bromthymol blue and Phenolphthalein can be added to other chemicals to determine acidity or basicity. Other reactions can be observed as well when different chemicals are added to each other.
This experiment involved placing drops of specified chemicals into a well on a 96well plate. Each well number was recorded along with question number and name of chemicals involved. Two drops of a chemical were placed in a well along with two drops of another chemical. Chemical reactions and color changes were recorded in Data Table 1.
During the experiments a few problems were encountered. One of the chemicals provided differed slightly from chemical description in the lab manual. The lab manual called for the chemical NH3 which is Ammonia. The chemical provided was an Aqueous Ammonia solution of NH4OH. When holding up the solution of AgNO3 and NH4OH to a light source for 5 minutes it was observed that no reactions took place despite the information contained in the lab manual. Also while testing the household chemical Brite, It was observed that the Bromthymol Blue changed to a green color that was not observed in any other test involving BTB.
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?
To test for the presence of sodium bicarbonate you could collect a sample of the household product and add HCl to it and see if you observe any CO2 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 (at least 3) household items including household cleaning products with bromothymol blue. Rinse the pipet well before using