Absorbance at 540 nm of Bromocresol Purple DilutionSeries
| test tube | concentration of sample (ug/mL) | A540 nm | BcP dilution |
| 1 | 0 | 0 | n/a |
| 2 | 0.9375 | 0.041 | 1:16 |
| 3 | 1.875 | 0.08 | 1:08 |
| 4 | 3.75 | 0.155 | 1:04 |
| 5 | 7.5 | 0.306 | 1:02 |
| 6 | 15 | 0.614 | 0:00 |
1. The point 0/0 is an important and valid point on this graph.Why? (Explain)Â Â Explain how a hand-drawn graph and excelgraph are similar or different.
2. How is the Beer’s Law equation similar to that of a straightline? Explain each component using the letter of the component andusing a set of your experimental values. BCP: 0.015M
3. Evaluate your data using the Beer’s Law equation: use theabsorbance reading for the highest concentration of a solution,determine the extinction coefficient for the BCP solution you weregiven. Do you get the same answer if you make this calculation atanother concentration?
4. Select 2 random absorbance readings on your line (that youdid not actually measure) and explain two different ways you canuse your graph to determine the concentration of BCP (µg/mL) of theunknown solutions that might have the selected absorbancevalues.  ***Provide the results; what values do youdetermine to be the concentrations of your 2 random absorbancereadings?
5. Explain why we refer to a graph such as the one you justconstructed as a “standard     curve†or a“calibration curve.†How would a graph such as this one beuseful?
