AP Chemistry U14-15
Chater 14-15 Acids and Bases
Lab 2
In this lab we will utilize the
behavior of a class of compounds called indicators. Indicators are materials
that change color behavior in the presence of various amounts of acid or H+
or H3O+ concentration. We will be attempting to determine
the acid/base behavior of a series of systems by their collective color
behaviors.
There will be 4 different samples to
test using the indicators provided. Place a small # of drops in the bottom of a
test tube and place one drop of the indicator in the same tube. Record the
color behaviors of all samples in all indicators in a similar manner. Your data
should be inserted into the grid from below:
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Bromocrestol Green |
Litmus |
Bromothymol Blue |
Methyl Red |
Methyl Orange |
Thymol Blue |
Phenolpthalien |
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Sample 1 |
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Sample 2 |
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Sample 3 |
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Sample 4 |
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From this behavior determine the approximate pH of the samples.
1. Cite color behavior for each of the indicators on the grid below
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pH1 |
pH2 |
pH3 |
pH4 |
pH5 |
pH6 |
pH7 |
pH8 |
pH9 |
pH10 |
pH11 |
pH12 |
pH13 |
pH14 |
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BCG |
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L |
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BTB |
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MR |
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MO |
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TB |
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P |
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2. State the approximate pH of the unknowns and why below
sample 1-
sample 2-
sample 3-
sample 4-