Kasra Chaharlang We use several textbooks, authors include: Klein or Wade or Janice Smith. 

Hi Kasra, our instructors use multiple Organic Chemistry textbooks and of course they studied these concepts while getting their degrees.

Was there a specific part or example in the video that didn't make sense? 

Pradhikshan Yes that also works.

Yes, Hydrohalogenation and Hydrogen Halide Addition are essentially the same reaction, just described using different terminology.

Both refer to the addition of a hydrogen halide (HX), such as HCl, HBr, or HI, across a double bond (alkene) or triple bond (alkyne).

Hydrohalogenation = A more concise term used in organic chemistry.

Hydrogen Halide Addition = A descriptive phrase that highlights the specific reagent.

Thank you for the feedback Hallie! 

Great question! You actually can use o-, m-, and p- even if the two substituents are different, as long as there are only two total groups on the benzene ring. Once there are more than two substituents, we switch to numbering the ring instead.

We have a video that will help you learn how to name alkanes this is best because you'll be tested on how to name alkanes on exams. 

Yes that's correct the benzene would instead be the parent chain. Parent chain goes to the longest carbon chain. 

In this resonance structure, we’re not adding or removing atoms, just moving electrons (lone pairs and pi bonds). So if there’s a double bond between carbon and oxygen to start, that carbon doesn’t have a hydrogen in the first place.

The resonance structure on the right still has the same number of atoms, just a different arrangement of electrons. And that carbon does have four bonds total: three to carbon atoms and one to oxygen. But when the pi electrons move onto the oxygen, carbon loses electron density, so it ends up with a formal positive charge. You can see this movement of electrons and where they went in purple.

After you watch this I highly recommend the next two videos they will help you practice these concepts even more:

Study With Us 

Practice Problem: Drawing All Resonance Forms That Stabilize a Carbocation

That would give nitrogen 4 bonds and no formal charge, which violates the octet rule and formal charge rules. If nitrogen is making 4 bonds (2 double bonds), it’s sharing 8 electrons, but nitrogen only has 5 valence electrons. Valid resonance structures share the same total number of electrons, same atom connectivity, and obey the octet rule.

The two resonance forms shown, where the double bond switches between oxygens are the only valid ones.

After you watch this I highly recommend the next two videos they will help you practice these concepts even more:

Study With Us 

Practice Problem: Drawing All Resonance Forms That Stabilize a Carbocation