MathBench > Measurement

Straight Lines/ Standard Curves

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John and Suzy want to measure the strength of various mixtures of red koolaid. After finding the proper wavelength, they run 10, 20, 40, and 80% solutions through a spec, and get the following data:

concentration

10%

20%

40%

80%

absorbance

.31 OD

.59 OD

1.2 OD

2.3 OD

 

1

 

Then they go to the State Fair and get samples of red koolaid from 3 different vendors. These samples have absorbances of 0.7, 1.5, and 2.6 OD. How strong is each glass of koolaid?

First, what is e?

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I think I have the answer: e = 0.03 OD / percent koolaid.

So far, we know that e = 0.03 OD / percent koolaid. Fitting that into our equation, we get

OD = 0.03 c

Now that you have e, what are the concentrations of the three koolaid samples
(their OD's were 0.7, 1.5, and 2.6 AU's)

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I think I have the answer: 0.7/0.03 = 23%
1.5/0.03=50%
2.6/0.03 = 87%