laying here from land for side acecomm in this video
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will discuss the what and how behind the alkene reaction mechanisms
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before we can understand the specific out keen reactions
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we have to understand what is an alkene how does it look
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how does the act and white this want to react an alkene
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is simply a hydrocarbon or a molecule
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that have a carbon to carbon that would bar the double bond
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is s he you hybridized which makes the molecule trigonal
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plainer and get the Adams a bond angle
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120 degrees let's take a look at a sample molecule
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where I have carbon double bound for carbon and we'll just
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and little green line to represent hydrogen if I drop a small group from
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the side
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I start up with my sigma bonds which is current single mound for the carbon
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and single bound each of the two hydrogen
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three sigma bonds is where I get s you have a situation
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if you're unfamiliar please go back and look at my hybridization
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tutorial video because this is important understand the outgoing reaction
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in addition to the sp2 hybrid orbitals
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I also have a pee orbital which said happen pop
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and happen bottom I've the carbon Adam and if I have the
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to you the orbital next to each other the electrons in them or
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overlap on pop for the pipe ap and then on bottom
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where the pie bottom and this is what makes
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the pipe bomb for the carbon-carbon double are imagine that this is a side
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ways
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image where the hydrogens and
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the carbons are in the plane notice have a pie electrons
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sitting a bomb and below be black for trigonal planar molecule
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this makes it a lot easier for these electrons interact with other molecules
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and their first start the alkene reaction another important concept
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understand for alkene reactions
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in the definition love a nucleophile
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and an electric I am and I'm sure you will see needs again and again
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but some students memorize them and don't know how to apply it to reactions
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if I look at the word nuclear fire I can see that it comes from the words
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nucleus loving which in chemistry translates
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you positive seeking the same thing for electrify
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coming from the words electron loving which translates
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to negative seeking in my videos
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I we representing the nucleophile by the letters
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and you with the pair electrons to show that these are
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electron-rich and therefore positive speaking
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and I will represent a lecture filed with E boss to show that this
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is positive rich or partially positive
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and therefore negative seeking
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and this leads me to the founding principle
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I'll organic chemistry mechanism most in the mechanism
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that you will see inorganic chemistry will start out with
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some nuclear file and some electric I'm
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a nucleophile being electron-rich looks for the partially positive or positive
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electrify
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impacts this then leads to a product
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a a nuclear file bound to an electric power
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if you look at every reaction as wanted the new clean file
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what if the electric power what makes this molecule nuclear power what makes
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the electrons want to attack
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with the electric power what makes a partially positive why can't the track
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pack when the new clean file at PAX the lecture file
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what does the product look like what the charges were quite
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it you can apply these questions for these concepts every reaction
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it will be more about understanding and applying concepts
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less about memorization and you will find that you understand what's going on
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a lot better let's apply and then few a hypothetical mechanism
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I'll start with a to you nutin
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with a pipe on between carbon to you and carbon
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re I will not shoot stereochemistry miss molecule
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because I want to focus on a comp the pie electron
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in the carbon-carbon double bond are electron-rich
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and that makes the alkene a nucleophilic
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molecule if I bring any random electric file
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near this new plan I'll the pilot chance will reach out
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to grab the electric I'm raping the carbon-carbon double bond in the process
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always show the reaction arrow as starting
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from the lone pair of electrons reaching out towards the electric power
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work towards the positive molecule getting pack
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never ever ever BACnet
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arrow from the positive Adam these Adam get packed but they do not have
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electrons
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to provide 48 pack once you have shown
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be electron and having them you show a reaction our
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and then drive your product the carbon skeleton for buchanan
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Napoli pain has not changed recall but I had a pile Actron
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on both Harbin to and carbon 3 Sen
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this is a symmetrical starting molecule it doesn't matter if I put the electrify
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like apartments UN
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3 if however you're dealing with a primary secondary or tertiary carbon
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we I feel like to file will make a difference but we'll look at these
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in specific reaction in later videos for now
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I will randomly choose to show that the electric file
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connected on the right and the box connecting the electric file
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is made out and the two electrons that did the attacking
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now here is the key concept to pay attention to you
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carved into have a barn now it has the electric power pack
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it had for Mon in you taking
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now it has for bonds as well don't forget that there's that
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invisible hydrogen I've been three however
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having had just one hydrogen now has
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only three mom and this gives it a formal charge
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a positive one you can mara
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I have a formal charge making a quick count be electron
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and applying the formal charge formula or you can try to understand what happen
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we started with a double bond on the carbon
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the electrons from the double bond mood to be a lecture file
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leaving the carbon with nothing the carbon being the pension
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now has a positive charge with me it's waiting for something else the common
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now in both electron if you're not
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you comfortable with this concept check out my car broke have an
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video and hopefully that will make it clear clean this reaction step
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left me with the car broke at an intermediate there now
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I can read an alliance what is my nuclear file
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and what is my electropop given that my car broke at I am has a positive charge
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this becomes the a lecture file I've been mixed reactions
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that and random new clean file
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in pollution will now react they continue the sequence
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or the mechanism this reaction once again
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the electrons on the nucleophile will reach ap to impact the positive carbon
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giving me the final product in this mechanism
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I I have accounted for the change in charge have nuclear file
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an electrophile because that will depend on the specific molecules
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or Adam thing question the purpose of this many a
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is you a salad understanding what an alkene
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and how an alkene reacts in future videos
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and the alkene reaction series I'm take you through the different reactions
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one at a time to show you how the molecules react how the outcome
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in track and how you can't figure out the product even you haven't seen that
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reaction previously I will be happy to answer any additional mechanism question
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in my weekly review sessions line online
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and from the comfort of your home I also offer one-on-one private tutoring
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visit my website for more information layer first I dot com
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flash organic chemistry