Sounds like O-chem is the "weed-em-out" class, most tough programs have them. Super hard taught by a super demanding teacher, if you pass it you are good to go for the rest of the program. Active circuit design was mine, 1/3 of the class didn't pass and the teacher was a dick. I barely got a C.
The first one for me was Calc 1. Probably 1200 kids the first day. A good supply of hot chicks. After the first exam, the class probably had like 700 kids and the hot chick supply jumped off a cliff.
Organic Chemistry like you said is another one like that, and so are the harder Physics pre-reqs. It was to find out, if you had the math to hack it in engineering, did you have the aptitude in the relevant science. Some kids who thought they were pre-med or a hardcore biological track took Organic Chemistry and there was a change in major. Some kids who thought they were going to Mars on the space shuttle barely got a C in the harder Physics and there was a change in major.
Digital Design was tough but that was more 3-4k level, and it wasn't as bad as Microprocessors, which was ghastly. For some reason Computer Engineers at Florida had to take all these difficult-on-purpose hardware classes, but the Electrical Engineers got to pick from a big basket, and they almost all skirted around the edges. They had to take Electronic Circuits with us and told us that was the hard one since they almost all ducked Digital Design and Microprocessors - or wished they had.
For the mechanicals, the Thermodynamics classes were there upper-level weedouts. I'm sure other tracks had designated 3-4k level classes like that.
The overwhelming majority of the 3-4k classes, the test average was in the 30s and 40s and curved. These tests were impossible. One fucking prodigy would get like a 65 and we'd get a 10 minute lecture about how the other 150 kids in the auditorium sucked. It's like, look asshole, 60% of this class lives in the computer lab. They were smartest kid in their village in Uttar Pradesh or Bhaghavhaghabhad or whatever the fuck, and one kid gets a 65 and nobody else clears 50 and you want to give everyone else a D or F.
Mind you, nooooooooooooooobody would put their name on paper to have the professor reprimanded or whatever. You learned after the very first time you asked for anything, not to ask for anything. And if you had a question, you'd better ask the slave labor grad student TA instead of showing your face at actual professor office hours.
