Exam 1, Organic Chemistry I Live Review (2022)

[@jdekk4487]

great video, as for problem 8, wouldn't the most unstable structure be with the methyl eclipsed behind the "tert-butyl" group since CH3 is more "bulky" than Br?

[@catkat7673]

ty sir joe, helped me a lot, upload more videos . i love you ur videos.

[@eliyodaiken127]

1:21:57 Thanks so much for this great review! Why is Br aligned with tert-butyl more unstable then CH3 with tert-butyl? Thanks one again.

[@jOeCHEM]

Br is MASSIVE (in terms of molar mass) compared to a non-branched alkyl group such as a CH3 (by branched, I mean like isopropyl and t-butyl are branched substituents, whereas methyl/ethyl/propyl groups are not branched). So because Br has a molar mass of 79 g/mol and CH3 total has a molar mass of ~16 g/mol, a Br t-butyl steric hindrance is more unstable than CH3 t-butyl. Let me know if that makes sense or not!

[@esseless5715]

great video, helped a lot

[@dinamatari5193]

Great video but when solving 3c isn’t the unstable acid the weaker acid because the most stable/has resonance have a lower Pka and are stronger acids

[@jOeCHEM]

Hey, Dina! Thanks for watching! In terms of acids & bases, stable = weak since a weak acid/base came from a strong conjugate, so stable can also be used synonymously since it’s lower energetically than its strong counterpart. So just like weak = stable, strong = unstable, since a strong acid/base will react & do it’s job and move to its lower energy, more stable (aka weaker) counterpart. Did that make sense? Let me know if not!

[@dinamatari5193]

Thanks I think the wording makes it a bit more confusing. When looking at two different Lewis structures the one with a double bond would be more stable and have the lower pka making it the stronger acid. Correct? Is that different from that question or is it just looking at it in different terms such as energy

[@alexanderberhane4184]

I love you.

[@peon9476]

You explain the topics so well, I think i love you 🫠 Thank you so much for all your videos