The following experimental data was obtained by a student using a potassium perm

Question

The following experimental data was obtained by a student using a potassium permanganate solution. Answer the questions below

Test Tube # Absorbance Molarity

1 0.980 0.50

2 0.490 0.25

3 0.245 0.13

4 0.123 0.06

5 0.061 0.03

a. Using the above, what would be the molarities of this potassium permanganate, KMnO4, solution:

Unknown G=absorbance=0.81 =__________M

Unknown Z=absorbance=0.08 =__________M

Unknown K=absorbance=0.35 =__________M

b. Using the above, what would be the absorbance reading for these potassium permanganate, KMnO4, solutions:

Unknown 1=0.040M =_________absorbance

Unknown 2=0.020M =_________absorbance

Unknown 3=0.005M =_________absorbance

(note: test tube #, absorbance, molarity is written in a chart form)

Explanation / Answer

Okay. You're going to want to make a standard curve with absorbance on the y-axis vs. molarity on the x-axis to do this question. Then draw a line through all the points that you plot on that graph, and use that to answer the questions. For example, at 0.81 absorbance it will probably be around ~0.3-0.4 M, at 0.08 around ~0.035 M, and at 0.35 ~.0.18-0.20 M. Do the same for B, beacuse you can just draw a line from the axis to the trendline and that will give you the corresponding value of molarity or absorbance. So 0.040M would probably be around 0.08 absorbance, 0.020M would probably be around 0.05 absorbance, and 0.005M would probably be around 0.01 absorbance.

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