The first students left an hour early, the slowest stayed the entire period. There were hardly any questions for me
The students are introduced to IR spectroscopy in this lab - relate it back to the Food Dye lab and UV-vis spectroscopy to help them understand the concept. I do not usually get many questions about Part D, except for some students still confused with Lewis structures or polymer repeat units in Q19. Refer them back to Q2 from Part 1 that you passed back.
Make a set-up to show the students because the drawing in the manual is a bit confusing for them. Your buret clamp should be hanging from the faucet over the sink. There are rulers on the back flap of their lab manuals (which they can cut off to make it easier) - one partner adds water while the other one holds up the ruler to make measurements. They can weigh their bottles on the triple beam balances instead of the analytical balances. The PVA films do not always come away from the boat without tearing, so students with compromised samples can borrow data from a neighbor if they need it for their graph. Graphs are done by hand today, instead of on excel. It is easier for them to see the trend if they graph all lines on the same set of axes.
There are only 4 pairs of scissors per section, so have half your class start with the spectroscopy section.