Apex Learning: Chemistry Labs
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Questions for Observing and Inferring
For this question use the necessary data from Table 1.1. Even though you don’t know
the absolute concentration of the BTB on the paper towel as it wicks out, you can
graph its relative concentration.
Assume that the highest concentration of BTB is at
the center of the drop.
For convenience, call this highest concentration “100” and call
the concentration at the drops outermost edge “0”.
(You do not need to assign units,
because the concentrations you are graphing are relative concentrations.)
Draw a graph that shows the relative concentration of BTB from the center of the
drop to the edge of where the paper was wet.
In the above graph, did you have the concentration go to zero when you could no
longer see BTB? Or did you assume BTB was still there albeit at invisible levels?
Shade in the portions of both graphs where you were making assumptions (saying
things you have no evidence for) about the concentration of BTB.
From your data, could you infer that the paper towel is acidic?
See sample graph below question 3 below.