Purpose/Hypothesis: To observe how acids react with bases and examine reactions of common household cleaners and the macroscopic changes these chemicals undergo. I expect for each solution to react differently when mixed with acids and bases. Procedure:
I have a well-plate-96, a piece of white and black paper, and the chemicals from the Observation of Chemical Changes Experiment Bag. I used a different well for each combination of solutions. I placed two drops of one chemical then two drops of a different chemical. Observation:
NaHCO3 and HCl - Clear bubbles; bubbles did not fizz.
HCl and BTB- Color changes to orange after the BTB is added. NH3 and 1 drop of BTB- Turned dark blue.
HCl and Blue Dye - Turned dark blue
Blue Dye and NaOCl- Turned dark blue then aqua blue.
NaOCl and KI- Turned yellow.
KI and Pb(NO3)2- Cloudy yellow.
NaOH and phenolphthalein- Dark pink.
HCl and phenolphthalein- Clear w/ No bubbles.
NaOH and AgNO3 – Olive green.
AgNO3 and NH3- Clear w/ Bubbles
NH3 and CuSO4- Cloudy aqua blue.
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? *I would test it with HCl to see if it begins to bubble.
B. You know what color phenolphthalein and Bromthymol 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 Bromthymol 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. What do these results mean? *When mixed with Windex the solution remains blue. When mixed w/ Grease Lightening the solution remained blue. When mixed with Quick Shine Floor Finish Solution it turned yellow. C. You found a sample of a solution that has a faint odor resembling vinegar. You are verifying that it is indeed vinegar and you add a few drops of phenolphthalein. The sample turns pink. What assumption can you make about this sample? *Phenolphthalein turns pink when mixed with a base. Vinegar is not a base therefore the sample is not vinegar. E. You decided to investigate if the new wave of VitaminWater is pH neutral: neither too acidic nor too basic. Using BTB (Bromthymol blue), you select five flavors of VitaminWater to test. Three of the flavor-samples turn a murky green, indicating the likelihood of acid/base balance. Of the two remaining, one turns slightly yellow, while one remains blue. What can you assume about the acid/base content of these particular flavors of VitaminWater? *The one that turned slightly yellow is more acidic than the basic. The one that remained blue is more basic than acidic. F. You have read that a new brand of hair tonic is supposed to contain lead (an ingredient in Grecian Formula). Devise a simple test to confirm the presence of absence of lead in that hair tonic. *I would mix Kl with a sample of the hair tonic to see if it turns a cloudy yellow. Conclusion:
This experiment taught me how to interpret acids and bases and how they react with eachother, and how to interpret what each kind of reaction could mean.