In this video, we will go through a few handy tips and tricks to complete lab one
of AP Chemistry Investigations. To do so, we will be using a spectrophotometer, the
Vernier SpectroVis Plus spectrophotometer and a Vernier LabQuest 2 data collection
device. The goal of lab one is to determine the amount of food dye in a
sports beverage, and we're going to be looking at blue one food dye in this
example. To begin with the spectrophotometer, the first thing that we
want to do is calibrate the SpectroVis Plus, and we will do so by placing a
cuvette of distilled water, our solvent. Place it in the SpectroVis Plus. And on
the LabQuest 2, we will tap Sensors, then choose Calibrate from the menu, and
Spectrometer. Because the SpectroVis Plus has been warming up, for sake of time, I
will tap Skip Warmup, and then Finish Calibration in order to complete the
process. Now that we have completed that process, we are ready to measure the
amount of food dye that is in this sports beverage. On the LabQuest 2, we're going
to make one more change in order to make our readings proper for this experiment.
We will go back to the Sensors menu, choose Change Units. And on this menu, we
will choose "% Transmittance." Now that we've done that, we will place our sample
of the sports drink in the SpectroVis Plus and again press the Play button
to collect our data. Once
we see a graph of the data, we'll stop the data collection. And now look at the
graph, and begin to take the steps to finish our analysis. First, notice that
there is a multicolored backdrop on the graph itself to give us a handy reference
of the visible spectrum. However, if you don't wish to see that full-color
backdrop, tap twice rather quickly at the top of the graph, and it will be turned
into a slim strip that still gives us that color reference at the top of the graph.
And again, if you want to see the full backdrop tap twice near the top of the
graph to return it to its beginning point. Last thing, we want to select a wavelength
to do our analysis of standard samples that we will prepare. I will tap twice
here to dismiss that color a bit. Very easy to select a wavelength on the graph.
We simply tap anywhere on the graph to select a spot. Notice that on the
right-hand side of the graph, we are told that the wavelength right now that we've
selected is 638.1 nanometers, and the transmittance is a little bit more than
33.6%. If I move by tapping again, I've selected a different wavelength. Somewhere
near the minimum readings on my spectrophotometer is where I will get the
best results when I do my subsequent testing. For more videos on the use of the
SpectroVis Plus Spectrophotometer, please visit the Vernier website.