How would you get the concentration(ppm) of a sample from absorbance?

Absorbance of standard = 2.55
Absorbance of sample = 2.31
Wavelength of machine 345nm
slit lenght = 1cm
time = 2s
The metal being tested is Copper and the concentration of the standard is 8ppm.

Absorbance std = k*concn std

2.55 = k*8
Solve for k.

Absorbance sample = k*concn sample
2.31 = k from above*concn sample
Solve for c sample.

To determine the concentration of the sample in parts per million (ppm) from absorbance, you need to use a calibration curve. Here's the step-by-step process:

1. Prepare a series of standard solutions with known concentrations of copper. In this case, the concentration of the standard is given as 8 ppm (parts per million).

2. Measure the absorbance of each standard solution using the same instrument and conditions as the sample. In this case, the absorbance of the standard is given as 2.55.

3. Plot a calibration curve by graphing the concentrations of the standard solutions on the x-axis and the corresponding absorbance values on the y-axis.

4. Once the calibration curve is plotted, measure the absorbance of the sample using the same instrument and conditions. In this case, the absorbance of the sample is given as 2.31.

5. Using the calibration curve, find the concentration of the sample corresponding to its absorbance value. Locate the absorbance value of the sample on the y-axis of the graph and draw a horizontal line across to intersect the calibration curve. From the point of intersection, draw a vertical line down to the x-axis and read the corresponding concentration value. This gives you the concentration of the sample in ppm.

Note: The wavelength of the machine (345 nm), slit length (1 cm), and time (2 s) are given parameters that ensure consistent measurement conditions during the experiment.

By following this procedure and referencing the calibration curve, you can determine the concentration of the sample from its absorbance.