Vocab
Sonicator- machine that emits ultrasonic waves through a water bath to agitate or mix particles
Spectrophotometer (Spec)- machine that measures the reflection/transmission of particles as a function of wavelength; collects data in absorbance units (AU)
After further research on phenol red, we discovered that we had overlooked that there are two different types of the same molecule; one for acids and one for bases, both of which carry different wavelengths in the visible spectrum. After changing the wavelength preference on the spectrophotometer from 550 to 440, results became more clear. Our process continued. Using the same stock solution as yesterday, I calculated 4 different dilutions and tested their absorbency with the spec. Unfortunately results were not linear (that means I probably messed up). Being my first day to work independently, I wanted everything to turn out right. We then had to look at my calculations and measurement techniques and all of them looked correct. I was excited that at least I had done everything I was supposed to do. In the end I just remade the dilutions and tested them again. With the same calculations and tools, the results turned out to be completely different and also ended up being linear. I guess there is a reason for making a wide range of samples and repeating procedures for accuracy. Tomorrow we will imput the results into excel, create a graph of the data, and measure my standard deviation and coefficient variation.
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