Twelve students were enrolled in my course in the fall 2016. The average overall score for these problems was 78%.
For problem 1b, I calculated the oxidation numbers using the familiar general chemistry method of assigning oxygen as –2 and hydrogen as +1. Students recently coming through organic may have some other way to do it, and you may need to provide directions for your students about your preferred method. I think I could have worded part (c) better to try to emphasize the redox processes involved. I wanted them to think of combustion, but I think they needed to be specifically prompted, such as "Give an example of the combustion processes that generate CO2 and trace the oxidation state of carbon through the reaction." Overall my students scored 86% on problem 1.
The second problem (about another method that could be used to measure d-spacing) was fairly hit or miss. Five students got full credit, six students got 3 points, and one got zero. Eleven out of twelve did answer part (a) correctly. I realized as I made this LO that the article says the carbon-based material doesn’t diffract X-rays, but doesn’t actually directly explain whether or not the Cu nanoparticles diffracted X-rays, so you may need to adjust the question to be technically accurate.
Question three (re: surfactants in nanoparticle synthesis) referred back to knowledge from earlier in the course. The overall score was 61%.
Question 4 (define and describe electrodes) was fairly straightforward, and students scored 85%.
Question 5 caused some confusion, as some students missed that I was looking for “carbon-containing” products only. I didn’t count off for that mistake, but it made the problem harder for students who included hydrogen in each box. Overall, students did very well on this problem (89% correct).
Question 6 – again, not too much trouble here (84% correct).
Question 7 – I was surprised that students didn’t do better on this question, as I thought that water reduction was mentioned often in the article. Only three (of 12) students scored 5 points on this problem, and the average score was 53%. This was probably my favorite question, as it foreshadows electrochemistry topics I cover in my inorganic course.