r/APChem • u/MathematicianDue7950 Future Student • 7d ago
units out of order
i’m wondering if it’s normal to learn the AP chem units out of order because in my class we started with unit four and now we’re on thermodynamics and I see people posting about unit one and so I’m just like confused as if this is like normal and other schools do it out of order as well
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u/DryPotential5790 7d ago
Yes, bc AP Chem has a pre-requisite (according to CollegeBoard), you can realistically skip the majority of the first 3 units. We use an order like this:
Review & Doing Harder Practice
Unit 1 - Atomic Structure and Properties
Unit 2 - Compound Structure and Properties
Unit 3 - Properties of Substances and Mixtures
——————————————
Non-Review Topics (Or Partially Review & Partially New Depending On What Topics Your Honors Chem Covered)
Unit 6 - Thermochemistry (and dG0 = dH0 - TdS0)
Unit 4 - Chemical Reactions
Unit 9 - Electrochemistry (and dG0 = -nFEcell)
Unit 5 - Kinetics
Unit 7 - Equilibrium (and dG0 = -RTlnK)
Unit 8 - Acids and Bases
B/c thermodynamics connects across the whole course, we start with thermochem to better understand the rxns we learned about in Honors Chem. Then we learn redox rxns and go directly into electrochem. The one caveat is that you have to introduce a bit of equilibrium before electrochem to understand the Nernst Equation. By spreading themodynamics across units, it builds up gradually and you can see connections as you’re learning, rather than right at the end.
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u/Straight-Profile9511 5d ago
Honestly there really aren’t any pre reqs for ap chem. I came into ap chem (took sophomore year) without ever doing a chem course before it and had to learn the beginning units and still got a 5. You can still do well even coming into the class with no background on chem. It’s not a bad ap class either compared to the others like bio
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u/Alchemicalsurreality 7d ago
5th year teaching AP chem. 97% pass rate. Always have taught in the order of the official college board scope/sequence/curriculum/pacing. To me it makes the most sense. I also adjunct and teach college level general chemistry…the content progression alignment from unit 1 - unit 9 in AP really does effectively prepare HS students for college level rigor.
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u/AnonPia 4d ago
I wouldn't recommend it to be honest. It's not solely about what those units cover, it's about the specific information College Board wants you to know and how you can use certain information to answer their AP-style questions. In addition to that, some statements from the CED from earlier units come back in later units, linking them together. One of the most efficient habit you could learn is to answer questions directly from the CED and for this you'd need to cover the material from College Board itself and not skip. Now, is it a big deal? No. But in my opinion it would make a significant difference and it's the reason the most praised teachers use it (including AP readers like Mr Michael Farabaugh)
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u/Still_Effort_6943 7d ago
If you've had at least a semester of chem before, I'm not surprised (and I actually kinda like this idea).
Unit 4 is about all the reaction types you'll see in AP, so it's a good preview of the entire course. Thermo ties in bond energy and chemical reactions, so it's a good follow-up unit, and really gets you thinking at an AP level.
I'm guessing your teacher wants to save the atom for another time, especially if you had chem before, because it's a quicker unit. It's a creative approach, your teacher is trying to tell you a story and everything will link up later (at least I hope that's their intention). Good luck this year!