I am afraid AP teachers (whoever they are: I'm the product of a different system) may
not be up to the task. They are teachers and by definition may have an MSc at best. You need teachers
that are the brightest of the bright namely a PhD or soon to be a PhD. Professors of the future,
to train you to think outside the box. And whoever says that this can't be done is mistaken!
I should have added the grad student that tutored me was from probably the best school for
chemistry in the world at the time. And yes I passed that University's rigorous written and oral
exams and did my BSc there. (Hint: I had Wilkinson as one of my professors.)
So, go out and buy yourself Geoff Raynor-Canham's Descriptive Chemistry 5th ed and start reading
and learning. Grignard rgnts and batteries are all in there. (Dr R-C, "Geoff" was in the year
ahead of mine!)
I am a great believer at struggling for hours on problems: helps the neurons to make shorter connections.
Not many students then or, especially, now do that.
If you had spent just two min of the Mg3N2 problem you would have had (perhaps!) time to check those units.
Always look at your answer to see that it make sense. If your calc density is 4.12×10^22 g cm^-3
you have probable forgotten Mr Avogadro's const (could be a neutron star?). Know Li has a density of 0.53 and Os 22.6
g cm^-3 so any density outside these values is wrong. etc etc
Practice, practice, practice -until it becomes second nature and from which comes confidence,
and nerves of steel. And above all, have fun!!
best wishes.