How would each of the following affect the Cr(VI) concentration determined in this experiment? Justify the answers with an explanation.
In the experiment, absorption spectroscopy was used to obtain the concentration of Cr(VI) ions.
1) A student adds more standard solution than intended in the initial dilution step when performing serial dilutions.
This would cause an increase because the other series of dilutions would have more concentration, right?
2) As student only fills a cuvette 1/4 full when taking the absorption spectrum of the simulated lake water sample.
There would be a decrease because the scanner probably did not scan the liquid obtaining little or no concentration, right?
3) A student mistakenly uses the cuvette containing the most dilute standard solution, rather than the cuvette containing deionized water, as the blank solution.
I don't understand why there would be lower concentration of Cr(VI) ion...
4) A student does not wipe off dirty fingerprints on the cuvette containing the unknown solution before measuring its absorbance.
There would be more absorbance since the oil from the fingers would absorb some amount of light, leading to a higher concentration of Cr(VI) in the unknown solution, right?
Thank you for helping!