In a hurry to complete the experiment, Joseph failed to calibrate the spectrophotometer. As a result, all absorbance values for the standard solutions that are measured and recorded are too high. How will this affect the following for the Test Solutions?

Joseph will not get the correct results for his samples. The spectophotometer will measure wrong absorbance values for the sample. It is highly advised to callibrate the instrument by first setting the absorbance of the solvent to zero. After it is done, only then one must determine the absorbance of the test solutions.