Post-Lab

Graduated cylinders are not as precisely calibrated as burets or volumetric pipets. Briefly explain why it is acceptable to measure the K1 and HC1 solutions used in the titration with graduated cylinders rather than with pipets or burets. 

Would the following procedural errors result in an incorrectly high or low calculated percent NaOCl in commercial bleaching solution Briefly explain. 

If a student failed to drain completely the volumetric pipet when transferring the diluted bleach, this error would result in an incorrectly low percent of NaOCl. NaOCl is the active ingredient in bleach. If incorrect low amounts are transferred to the Erlenmeyer flask, then the NaOCl concentration is also incorrect. 

If a student blew drops of commercial bleaching solution into the volumetric flask, then that student has introduced another set of chemicals from the moisture of their mouth into the solution, altering the experiment and altering the results. 

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VIII. Conclusions and/or Post-lab Summarize in a paragraph what the laboratory data showed. Include percent error(s) if possible. This is also a good area to include any statistical work comparing your work with class averages or expected/theoretical results. Some laboratory manuals include Post-Lab questions, which would be included here. 

A meso form with any one of the enantiomers of tartaric acid represents a pair of diastereomers. Although it may not be true for this compound because of the meso form, in general, if you have n stereocenters, there are 2n stereoisomers possible (see Post-Lab question no. 3). 

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