4. Chromatograms of compounds A and B were obtained at the same flow rate with two columns of equal length (time in min). Column 1 Column 2 Detector response

(b) In a chromatographic analysis of low molecular-weight acids, butyric acid and isobutyric acid elute with a retention time 7-63 min and 5-78 min, respectively. The column void time is 0-31 min. What are the selectivity factors for isobutyric acid and butyric acid? of

Would your absorbance value be too high or too low if the level of indicator were above the mark on the pipet when delivered to the flask? Explain your answer.

1. Why is a calibration curve necessary for this analytical technique? 4