Summative Assessment – Raw Data
In the following tables you will find the data needed to complete your lab report. Table 1
shows the absorbance values of standard solutions of paracetamol in three repeats. In table
2 you can find the absorbance values of solution C prepared into triplicate.
Table1: absorbance values of standard solutions
Standard # 1 2 3 4 5
Absorbance
at 243 nm
0.072 0.142 0.278 0.432 0.567
0.068 0.136 0.283 0.431 0.558
0.071 0.139 0.277 0.425 0.562
Table 2: absorbance values of solution C in three repeats
Solution C 1 2 3
Absorbance at
243 nm 0.415 0.412 0.417
Use data in table 1 to create the calibration curve; calculate the average absorbance for
each standard, round the averages to 3 decimal places, and plot the graph of average
absorbance versus concentrations. (Hint: Do not use the number of standard solution
instead of the concentration values!) Find the regression equation and the r 2 of the
standard curve.
Calculate the average absorbance for the three triplicates of solution C which can be found
in table 2. Then calculate the concentration using the regression equation.
Work backwards to calculate the concentration in both solutions B and A.
Once the concentration in solution A is calculated, you then have to find out the percentage
of paracetamol in the original sample (the powder that was used to produce solution A).
