Added: 2 years ago
From: EnderlePhD
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  • i dont get why do we have to have the valence electron?

  • @Algerie123Foot The Lewis structure is necessary in order to answer the question and the valence electrons help us draw the correct Lewis structure.

  • lost

  • @Sadie1307 lost what?

  • amazing!

  • That shirt is SO last decade

  • Can anyone explain to me how he figures out the total valence electron before he starts drawing?? That seems to be the the one trick I'm not getting =/ haha

  • @SpoilerofGames Count the valence electrons by looking at atoms given and find what column they are listed in the periodic table. Ex: CO2. C atom in column 4 and 2 O atoms in column 6. 4+6+6 = 16.

  • @EnderlePhD Thanks a bunch =)

  • Is there a reason H can only be bonded to the O in polyatomic ions? and is it only in polyatomic ions + only those elements?

  • @rose62892 It's a general rule for polyatomic ions with O atoms that I tell students. You can attempt to draw other configurations but you won't get a nice Lewis Structure.

  • You showed in 10 minutes what my teacher couldnt show in 10 weeks

  • i need help asap on CH3- for its molecular polarity and its dipole moments?

  • @untouchedpoop The Lewis structure is C single bonded to three different H atoms. The C atom also has a lone pair of electrons. With four groups and one lone pair this species is tetrahedral (electronic geo) and trigonal planar (molecular geo). In that case, it's polar. In another sense, most say that ions are always polar because they would form ionic compounds.

  • I am only giving it a thumbs up because the professor looks friendly :)

  • thanks young lady who asked for H2SO4

  • Lovein the old school chalk board :D

  • All symmetrical molecules are non-polar and all non-symmetrical are polar?

  • @h6233w For the most part, yes. If you have a question on a particular molecule then I'm happy to comment on it. Really, it has to do with the electron cloud distribution as determined by electronegativity.

  • You are the BEST teacher in the world. Thank you so much!!

  • you've taught me more in 10 minutes than my AP chem teacher has all year.

  • @theamazingnessapril lol, I can relate to you :P

  • do you have your own website?

  • i must have missed one...lol

  • so that means, all we have to do is to just look at shape and identify if it's symmetrical or not. If it is, then it's nonpolar but if not it's polar. But what about the electronegativity, isn't there's such a way about subtracting each element's electronegativity and then basing it on a table and then u identify if it's polar or nonpolar. And what about lone pairs for? Isn't it if there's a lone pair, then that means it's a polar if none then it's nonpolar. I'm quite confused here. X(

  • @shinichikudoconanful Yes, look at the symmetry and that accounts for EN. Consider HF. It is linear but not symmetric, thus polar. In terms of EN, there is an obvious difference, thus polar. Same answer. Lone pairs are a determining factor in shape which leads to symmetry so that is also already accounted for. There are some examples of shapes with lone pairs that are np such as linear (with 5 or 6 groups) or square planar. See other videos of mine and let me know if you are still stuck.

  • @EnderlePhD Thanks a lot!!! I kinda get it. But may I ask you a question if Carbonate is polar or nonpolar? My chemistry teacher says it's polar and has a dipole moment. I don't quite get it. Thanks again!!! :D

  • @shinichikudoconanful Ions are hard to comment on polarity and carbonate is an ion. One could say that if it existed by itself it would be nonpolar but it would really exist with a cation. With a cation, the species would be ionic and thus polar. You should ask your instructor how to best proceed when confronted with a ion and asked about polarity.

  • This guy is good

  • I know no one's asking about this but I'm learning at 14 :) Here in the Philippines, we have less levels in our education system.

  • i like this

  • I wish I had a chem professor like this guy. He actually teaches.

  • What age are you being taught this in the USA? Cos I'm 16, English and really confused.

  • @mrtictac94 hey! idk what age they teach it in the US, but here in singapore I'm learning it at 17.

  • @mrtictac94 We're learning it as freshmen (13-14 years old for most freshmen right now). I mean, I'm in Honors Integrated Science 1, but I'm pretty sure it's the same for everybody at our school.

  • very helpful a lot more clear then my professor...thank you!

  • Why did my chem textbook make dipole moment seem like some elaborate non-understandable concept? Thanks for clearing that up in the first minute.

  • @TarynnH ikr

  • So a dipole and polar are the same thing

    finally i get an answer on what dipole means

  • my chemistry teacher gotta watch this.....

    she need it much more than i do....

    awesome...explaination

  • This is incredibly helpful. Thank you

  • i was the 100th person to like this video.

  • i did the 100 thumbs up!

  • You are a good teacher.I like all your videos,espeacially the one on alcohols,phenols and ethers.

  • I want to thank you for posting these videos and whether it be you, the teacher, that is uploading these videos I thank you. You're a great teacher and I like how you slowly explain everything instead of just telling us what is what. I've had teachers that just tell me the facts, without the how or why. So again, thank you!

  • @MsCrumplehorn The arrow demonstrates the difference in electronegativity. The C atom is more electropositive than the O atom. You could also draw a partial positive charge on the C atom and a partial negative charge on the O atom.

  • Can these be compared in terms of polarity, as in can one molecule be more polar than another?

  • @jihadmeathello110 Yes, polarity is a similar term.

  • hi , can u explain me please how we do the lewis configuration of the CLO3F?

    please reply me faster cause i have a test in 2 days

    thank u

    ps: u explain very well

  • thanks helped me alot!

  • The answer to this matter is partially whether its symmetrical or not, but the electron negativity gives you the true aswer - if its polar or nonpolar. Why does he not explain electron negativity?

  • @dasistdas Typically, one uses bond dipoles to find the net dipole moment qualitatively though it is also found experimentally. Qualitatively, one can compare the EN difference for each bond and draw a resulting dipole. Through vector analysis, one can find the net dipole moment. In this video, you are just seeing the problem being solved but not the theory. Looking at molecular symmetry is a simple way to determine if there is a net dipole (same method actually).

  • difinitoin of diPole moment

  • enderle phd ? hmm.acaba buna ender ile phd de diyebilir miyiz? cevap verirsen cevabımı almış olurum zaten. thank you so much. that was very helpful.

  • Cool teacher person.... i have a question..... why do u look like your off American Pie?

  • To tell if its nonpolar or polar, cant you just ask yourself if its symmetrical? Why even bother with the dipoles :p It confuses me. so basically im asking are all symmetrical shapes nonpolar and all non-symmetrical polar?

  • @asdfghjkl019283 Yes, that's fine. Check out the video and you'll see I initially solved with the concept of symmetry. When students asked me for more detail, I explained using bond dipoles. To answer your last question: yes, it should be. If you think you find a counter-example, let me know and we can take a look at it.

  • @EnderlePhD this is not in the video, but why is PF5 nonpolar if it is not symmetrical? i have to choose between ClF3, PF3, PF5, SF4, and CH2F2. based on this logic, i'm confused as to why PF5 is nonpolar

  • @eerriikkaaaa First draw the PF5 Lewis structure (trigonal bipyramidal). See there are 2 Fs on the same axis (linear) which are symmetrical to each other (bond dipoles cancel). See 3 Fs that form a trigonal planar shape. The trigonal planar shape is symmetrical (bond dipoles cancel). In sum, all the bond dipoles cancel leaving the molecule polar. To say another way, any basic shape with no lone pairs on the center atom and identical atoms bonded to it is nonpolar.

  • i wos waching and the only thing i wos thingking wos is he gay?

  • @kilstas16 If you have a helpful comment, I'm happy to answer it. Otherwise, you can keep your comments to yourself.

  • @kilstas16

    Says more about then it does about him....

    Even if he is, he'd probably go for someone who can spell 'was' and 'thinking. Think you stumbled across 'drawing Lewis structures' when you meant to look for 'drawing with crayons.''

  • @kilstas16

    Says more about then it does about him....

    Even if he is, he'd probably go for someone who can spell 'was' and 'thinking. Think you stumbled across 'drawing Lewis structures' when you meant to look for 'drawing with crayons.''

  • PLEASE BE MY CHEM TEACHER

  • you are the man! thank you!

  • YOu are greattt!!

  • i really need this

  • it took me almost an hour to go through this section in my text book, and i still didnt get it...thanks for helping me understand it in 10 minutes!

  • wow you are good!

  • thank you. very helpful

  • at 5:45 you drew the arrow pointing to oxygen the more electronegative atom, but the latest IUPAC convention points the arrow from negative to positive.

  • @y100269 Really? That's interesting because I've always seen it in texts pointing from the electropositive to the electronegative element. Can you post the website or reference material for us? Thanks!

  • @EnderlePhD It's my textbook. Title: Discovering Chemistry I

    2010 - 2011 edition, published by the University of Western Ontario (uwo)

    authors: Dr. Kim Baines, Dr. Keith Griffiths, Dr. John Corrigan and Dr. Felix Lee

    chapter: 2.1; page: 2-6 (the 6th page of chapter 2)

    I'll send you Dr. Felix Lee's email (these names can be verified on uwo dot ca) i tried finding it online but it's too much of a hassle.

  • @y100269 Thanks for the info. I'm not sure why different texts teach this differently. Take home application: follow whatever your chemistry instructor does. If I find more info I'll post here.

  • @y100269 I think that EnderlePhD direction of an arrow is correct, because it always goes from negative to positive el. for example:

    from H to Cl or we can show why CO2 is unpolar, because eventough molecules do have polar bonds, because dipol bonds have oposite directions C=O=C, so dipol moment is zero! sry for my bad english! :)

  • @lowryderfly i did say negative to positive, he drew it from positive to negative which is fine, i'm just saying that the rule (IUPAC) has just recently changed.

  • @bomberfun1 Typo*... 3 PhD's if I remember correctly

  • Thanks! Test tomorrow, and just trying to suck all the lagg info in.

  • my chem teacher has worked on Harvard and Oxford, has 13 PhD's and this guy in youtube answered all my questions lol

  • @arredeck

    Re: "my chem teacher has worked on Harvard and Oxford, has 13 PhD's"

    Yeah and my name is Princess Yamamoto.

  • super duper helpful thanks!

  • great vid mate helped me alot!

  • Thank you, I am just starting organic-chem at my local community college. Hence, its been a while since high-school, so thank you so much for refreshing my memory as well as teaching me some new principle's.

  • your an amazing teacher - very patient. love this video. thanks. =)

  • You are greatly helping me cram for my exam tommorrow. It's like having mini-lectures but without all the bullshit stuffed into it to make it go for 1hr 20mins. Purified knowledge baby. I want to inject this shit.

  • VERY concise and appropriate way to explain this subject. You did not rush through the material too quickly although the ladies question on why the CO seems symmetrical I believe could best be answered by saying that one is more electronegative than the other, being in front of a class you did a great job overall.

  • Also, I relistened and saw that you did twice say that it's because theyre more electronegative and also that at the beginning of the question she answered her own question. Pretty strange, lol.

  • @dbm6969 Ha ha. Cool thanks!

  • good question at the end!

  • ok so, when drawing c-o. how can o have a triple bond? that makes no sense. it doesnt have a d orbital for bonding electrons so its max bonds it can make are two.......

  • This exercise is just drawing optimized Lewis structures without evaluating other chemistry aspects, which would be outside the scope of this class. However, the triple bond agrees with the MO diagram which shows a bond order of 3. Also, experimental data backs up the bond order of 3 (see "General Chemistry" Petrucci et al.).

  • Thank you so much. This was very helpful .

  • You are a very gifted teacher.

  • Great video!

  • This is a really good explanation, i just dont get this one thing in my chem class: why when you are drawing the shape do you draw some as a triangle/ slashed lines or just a normal line? so for example at 4:02?

  • That is to show u where the molecule is oriented in space the normal line means "the bond" is parallel to the chalkboard, in tetrahedral molecules which has bond angles of 109.5, meaning each bond is 109.5 degrees from the next bond. It is convenient to show the shape using triangle/ slashed lines or just a normal lines. The normal lines represent the bonds being parallel or laying on the chalkboard, usually it is convenient to show 2 "normal bonds". The slashed bond meaning behind the board.

  • its because hes trying to show the 3D orientation, the slashed lines means that functional group is behind the central atom, the shaded triangle line represents the bonded functional group that is infront and the line is just another bond to a functional group. good luck in ur chem class

  • Amazingly helpful. After sitting through college level Chemistry, and then getting ready to study for the final exam and realizing that I still had trouble with this, this video solved all my problems.

  • Nice, very helpful.

  • Wow you're awesome man!

  • this guy rocks! his students are soo lucky!

  • this helped me a lot, i wanted to raise my hand when i watched it haha

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