Before the analysis of chlorine can proceed, what is the necessary step to prepare the glassware?

To prepare glassware for chlorine analysis, it is crucial to eliminate any contaminants that may interfere with the results. Soaking the glassware in a 10 mg/L chlorine solution helps to passivate the glass and ensure that any remaining residues or impurities do not affect the readings of the chlorine concentration. This step enriches the surface with a known concentration of chlorine, making the glassware suitable for accurate analysis.

Using a solution of a specific concentration helps to stabilize the baseline for subsequent measurements, thus improving the reliability of the test results. This proactive approach is particularly important in analytical chemistry, where even trace contaminants can lead to significant errors in measurement. As a result, ensuring the glassware is conditioned with chlorine will help maintain the integrity and accuracy of the analysis.