H NMR Spectroscopy Review - Examples & Multiple Choice Practice Problems

Рет қаралды 523,244

8 жыл бұрын

This organic chemistry video provides a review of H NMR spectroscopy. It provides plenty of examples and multiple choice practice problems that you might encounter on your next test or exam. It discusses chemical shifts for common functional groups such as aldehydes, carboxylic acids, ethers, alkyl halides, and aromatic benzene rings. It provides a review of the H NMR signals and the spin spin splitting pattern of the n+1 rule that you need to know. It also shows you how to determine the number of signals in an h nmr spectrum and discusses the terms upfield and downfield so you can understand it.
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Here is a list of topics:
1. Common Chemical Shifts / H NMR Table Values
2. How To Find The Number of Signals
3. N + 1 rule - Spin Spin Splitting
4. How To Identify Identical Hydrogen Atoms
5. How To Draw a HMR Signals /Spectrum
6. Upfield vs Downfield
7. H-NMR Analysis and Integration
Disclaimer: Some of the links associated with this video may generate affiliate commissions on my behalf. As an amazon associate, I earn from qualifying purchases that you may make through such affiliate links.

Пікірлер: 151

@TheOrganicChemistryTutor 5 ай бұрын

Organic Chemistry PDF Worksheets: www.video-tutor.net/orgo-chem.html Full-Length Exams and Worksheets: www.patreon.com/MathScienceTutor/collections

@frost343434 5 жыл бұрын

Might as well be giving you my tuition money… doing a better job then my teacher. Thanks for this!

@saadmmcsoud1596 5 жыл бұрын

same here

@alkhan5445 2 жыл бұрын

Than

@Mariiiam 2 жыл бұрын

Patreon it is then

@TheOrganicChemistryTutor 5 жыл бұрын

at 5:38 - a simplified version of the n+1 rule was applied to get a quintet (5) for signal B. Even though most spectrums will show a signal that appears to be a quintet for this type of situation - it does not give the most accurate description of what is happening. The quintet signal is really an overlap of other signals. Proton A (3H) splits proton B into a quartet and Proton C splits proton B into a doublet giving us either a doublet of quartets (2 x 4) or a quartet of doublets (4 x 2) which gives us a total of 8 signals. Some spectrums won't show 8 signals but may show 5 due to an overlap of signals. Nevertheless, the simplified N+1 rule can still be used to help you get the right answer in some situations but it does not reflect what is truly happening in the molecule. A similar situation applies when protons B and D split the signal corresponding to protons C.

@calebriggins5628 4 жыл бұрын

Our teacher is literally giving us nmr (proton and carbon), mass spec, and ir and telling us to come up with a structure

@allieb3477 4 жыл бұрын

Same here. I´m afraid lol

@rishisolanki783 3 жыл бұрын

It's fun trust me😂

@Hehexddddd 3 жыл бұрын

Just google the molecular formula and add the functional group u obtained from ur ir then google should be smart enough to do ur work for u

@amacgregor92 3 жыл бұрын

@@Hehexddddd This won't help on the ACS

@ishaankulkarni849 3 жыл бұрын

Same here mate...just that the mass spec is missing..we have the molecular formula instead..

@alexanderechevarria93 5 жыл бұрын

Super helpful on H-NMR, the night before the EXAM... I appreciate videos likes these.

@karinj5677 5 жыл бұрын

hope ur exam went well :)

@davidkempjr.7045 8 жыл бұрын

Bro, I was following you and understanding your lecture. Thank you.

@arturobarchiesivitali397 5 жыл бұрын

What I love from u is that, despite oof how much I dont like this topic, you make me enjoy it. Thanks man!

@Dm-hz9mm 5 жыл бұрын

Who else is feeling 100x better?

@The-Khatalyst 2 жыл бұрын

5 years after this video and you're still saving lives. My professor explained the doublet, triplet, etc as, "You look like like your neighbor on NMR. So does a Russian and an Italian look the same? No. But when they are neighbors on the NMR they look like each other." No idea what the hell he was talking about. Thank you for the simple explanation.

@Schoolerino-pj8pu 4 ай бұрын

that's kinda racist ngl

@DeniseP 3 жыл бұрын

You really are the chemistry god LOL. Thank you so much for creating these videos. I've been watching them since Gen chm I and now im in Orgo II. Sooooo helpful.

@cm-pd2hx 6 жыл бұрын

"spin spin splittin" love how you say that, haha thanks for your help.. This channel gets me through life

@noahploof7967 Жыл бұрын

As an O chem tutor there is nothing nicer than your videos to refresh my memory on the material I purposely forgot.

@92jwiener 5 жыл бұрын

This helped me understand spin splitting way more than my class did. Thank you

@Annie-it1cw 4 жыл бұрын

The fact that your voice is also so soothing makes this 10x better. Thank you.

@nicolemcclurekurlbaum1462 6 жыл бұрын

Just wanted to say thank you for posting such great videos. Because of your reviews (and some work on this end internalizing your lessons), I did really well on the ochem portion of the DAT. And, now that I have to take ochem II, this video is about to save me the embarrassment of having forgotten literally everything I knew about NMR. Ha! So, yeah, thank you for taking the time to do such a great job. It's having a real, measurable impact on my life.

@TheOrganicChemistryTutor 6 жыл бұрын

Hi Nicole, I'm glad those videos prove very helpful to you. Thanks for posting this comment. I really appreciate it.

@mukundaneanthony1036 Жыл бұрын

Hi Nicole

@razabazal4669 4 жыл бұрын

aced my spec test could not have done it without your help thanks so much again and again and again!!!!!!

@MuhammadTariq-qn2wl 5 жыл бұрын

Great method of teaching.a river of knowlege about chemistry.

@joseliinbabee 4 жыл бұрын

i had been learning this for weeks and didn't understand it until right before my spec exam, only missed 1! thank you !!!

@homegirl934 2 жыл бұрын

Your lectures are always useful... thanks for being such a wonderful source of knowledge

@GreasyRhysi 4 жыл бұрын

OChem midterm in 5min and what do I watch? Thank god for this guy.

@amitsoni-rn9tq Жыл бұрын

Splitting patterns which you explained was really good;understood the exact concept and also after solving some problems..

@thaliahoyos6773 3 жыл бұрын

I can google whatever i need and one of your videos will always pop up... THANK YOU!

@joaovaldez9190 5 жыл бұрын

please make more videos on finding structure by looking at an H NMR spectrum with signals

@deborahessilfie8064 3 жыл бұрын

Woooow 👏👏👏 you make it easier to understand organic chemistry. Thank you very much 😊

@MuhammadQasim-fu4hb 2 жыл бұрын

You are extremely proficient at explaining concepts !

@fereshtehfarahani9709 3 жыл бұрын

Thanks for your teaching ❤️ i use your episode lots of the time and I solve my problems several times 🌹🌹🌹

@exaverymwasomola3615 7 жыл бұрын

be blessed Mr i was following you are lesson actually i got new concept

@SM-gc2tx 5 ай бұрын

you are a lifesaver. I go to lecture and it is all just a blur by the time I walk out & reread my notes. the text is useless. we have guided prctice on campus but we dont get through much in each session. in other words, I don't know what I would do without you!!

@michelleneman6883 8 жыл бұрын

So helpful thank you!!!

@michellla93 3 жыл бұрын

Love you Organic Chemistry Tutor!

@mukundaneanthony1036 Жыл бұрын

Thanks Mr, you people your really helping us a lot, like i can learn things even when iam still in the holiday

@Carolchew96 5 жыл бұрын

Your video helped me a lot, thank you!

@t.i628 6 жыл бұрын

Thanks so Much for the clarity. please make more videos. Grade saver!!!

@mohamedazizjaziri2444 3 жыл бұрын

All respects dude , thanks alot for your help U are really making it easy to understand not like my teacher in class 🙄😑

@haddadmj96 7 жыл бұрын

Very useful video, thank you so much!

@theadvancetradingacademy1033 2 жыл бұрын

I'm seeing this video after 5years of release... Thanks cause its very helpful

@chrisdubs_42 2 жыл бұрын

This man knows everything

@jeallybeanjohns2958 2 жыл бұрын

You save my life. Thank you very much ❤

@davidodubona1876 3 жыл бұрын

Thank you for this, you have saved my ass multiple times I have a question about the second multiple choice practice problem. I believe option "D" should have just 4 signals and not 5. 20:00, B and C should appear simultaneously. As soon as you can get back. Thank you!

@rithvikganti6252 3 жыл бұрын

this was excellent, thank you so much

@yikes9921 2 жыл бұрын

I would really love to meet you some day. Thank you so much!!

@shinygm715 5 жыл бұрын

Better Understanding👌

@emanalkhateeb5870 3 жыл бұрын

Much more love, much more respect bro.

@frankieaceves2279 5 жыл бұрын

You should make one on Carbon nmr

@_dilaraesenn 2 жыл бұрын

best video for this point so thank you💘

@Antheaojadi 6 жыл бұрын

at 13:48 why would it only be 2 signals and not 3? if you draw the line of symmetry aren't there 2 more groups unaccounted for?

@lavina3535 4 жыл бұрын

You are an angel, a lifesaver!!

@demiladecatherine5603 Жыл бұрын

Thank you so much for this

@natty573 3 жыл бұрын

Saved my life❤️

@abhipshitkalita9783 2 жыл бұрын

Thanks a lot sir. You are great

@mariamiqbal6304 Жыл бұрын

thnx a lot sir ..it help me a lot in Mphil

@syedwaseemulla95 2 жыл бұрын

My Great teacher...

@nasserBack 6 жыл бұрын

Please make videos for C-NMR and Mass spectrometry. I am welling to pay for both videos. All I care about is to pass these two complicated topics

@krish_krish354 6 жыл бұрын

Nice bro . keep it up

@ChrisBranleh 7 жыл бұрын

You da REAL MVP

@dorothyotogbolu6485 6 жыл бұрын

pls make more videos o n this topic

@wittyusername9544 Жыл бұрын

Please can you make a video on heterotopic, enantiotopic, diastereotopic, and homotopic hydrogens? It’s in the curriculum now.

@matymh944 5 жыл бұрын

Thank you so much 🌸🌸

@heatherbegley8473 7 жыл бұрын

Wouldn't the Hydrogens on the CH2 next to the chiral carbon in the first example produce two different signals? Or am I mistaken? That was a chiral carbon bonded to the bromine, correct?

@austintuttle5723 6 жыл бұрын

Heather Begley ... Yep. Those hydrogen's are diastereotopic. He made a mistake

@drgrunental3865 5 жыл бұрын

Why is that?

@ladyinred396 5 жыл бұрын

You are right

@LadyShaydex 5 жыл бұрын

Why would the two hydrogens on the CH2 produce 2 different signals? They're in the exact same spot with the exact same effect. They are both 2 carbons away from bromine. So they should produce 1 signal

@raanoooshh9296 4 жыл бұрын

They're in the same chemical environment. They are attached to the same carbon atom so they would only show as one signal.

@jadmelhem3827 4 жыл бұрын

Bro you saved my life

@begumozkardes6901 6 жыл бұрын

Thank you !!

@cdelcarmen90 6 жыл бұрын

awesome video, just wondering... 5:30 because the a and c protons are not equivalent shouldn't the N+1 rule be applied individually to each proton to find the signals for b? that would give a doublet of a quartet right?

@kingkaigus3222 6 жыл бұрын

Carlos Del Carmen thats what i thought. I thought the rule was if a hydrogen has two adjecent atoms with hydrogens of different signals. Then the rule is (n+1)(m+1)

@drgrunental3865 5 жыл бұрын

@@kingkaigus3222 what's m?

@nessyandtot 5 жыл бұрын

no, they are too far apart. They have to be within 3 bonds of each other to split...within 4 bonds if there is a double or triple as one of the bonds

@SpesMagisteriiGradus 5 ай бұрын

thank you!

@iivia 18 күн бұрын

Thank you sm❤

@mathieux2101 3 жыл бұрын

How is E 15:04 different than the Ds. The hydtogens are both attached to a carbon whose adjacent carbons are both secondary.

@emeka3033 3 жыл бұрын

Yes, I need clarification with this question as well

@wa3452 3 жыл бұрын

thanks, you are the best

@123anmerocks 5 жыл бұрын

do you a review video on NMR in HD?

@jackiepaper426 6 жыл бұрын

What if you don't know the chemical formula? What if all you have is the molar mass, IR and C and H NMR data?

@johnathancerda8976 4 жыл бұрын

Rule of 13

@akashsunil7464 Жыл бұрын

In the first question the ch2 has non equivalent hydrogen atoms next to it attached to ch3 and ch in different chemical environments so wouldn't complex spin spin coupling or signal splitting pattern occur so would the n+1 rule hold or can we just ignore it

@AllDayErrDay. 2 ай бұрын

Shouldn't the protons on the B Carbon at 4:05 be a tad bit further downfield (say 1.2-1.3) due to being closer to a partially positive CH? Just like the CH3 is on the D Carbon.

@amiraelbhery8120 7 жыл бұрын

it was very helpful for me thanks a lot

@ladyinred396 5 жыл бұрын

Why 5:32 hydrogens B are not doubled of quartet ?

@samrajabeen5089 6 жыл бұрын

Sir,you did'nt tell about chiral centre...there should be 5 signals in 1st example. is'nt .?

@emansalem5288 7 жыл бұрын

Your amazing more video please ☺️

@alisharo58 4 жыл бұрын

Also, at about 5:45, why are you not complex splitting the B and C hydrogens? You're doing the n+1 rule, even though the environments (the adjacent beta-hydrogens on each side of them) aren't equivalent? Why??

@ramayabowen294 4 жыл бұрын

I understood more in a 30 min video than i did in a whole month of class

@xiR3BORNix 5 жыл бұрын

Thank u mark wahlberg

@MR-lt3jj 4 жыл бұрын

@17:36 why isn't the C=O a signal? Wouldn't that make the compound have 4 signals? (You only marked 3)

@GalaxyDude96 2 жыл бұрын

@5:17 Aren't the two protons on the CH2 different since they are diastereotopic?

@HipHopFan1654 7 жыл бұрын

Love your videos! Quick question, my prof specifically said never to add neighboring hydrogens (for e.g. In the first problem when you added 1H + 3H for a CH2 carbon), and that it wouldn't turn into a quintet but into a doublet of quartets, so where you just simplifying the problem for this video purposes? Does that still stand for the same thing? And is it wrong?

@TokiBird 6 жыл бұрын

I saw what you just said in another video and got confused as well

@alejandropinedarojas48 5 жыл бұрын

That's only when the magnetic ambience of the hydrogens differs, the n+1 rules fails in these cases.

@hej-ky4qk 19 күн бұрын

thank you sair my posay gonna pass O chem

@eniamrahc73 6 жыл бұрын

God bless you

@AhmadNavidHazara 4 жыл бұрын

you saved my degree!

@BrunaLobo 5 жыл бұрын

Thank you 🙏🇧🇷

@tesfayeayisa1253 2 жыл бұрын

thanks its a great v

@deborahmwambazi9255 7 жыл бұрын

your the best

@marisacasciola7287 5 жыл бұрын

I don't understand how the example at 15:00 has symmetry at where he put a dotted line. Can anyone help me out? I think he place a D and the E in the wrong place.

@alejandropinedarojas48 5 жыл бұрын

The pi electrons of the aromatic ring aren't localized as he draws it.

@ertanissever7047 3 жыл бұрын

In the first example (4.25), A and D carbons are primer. Why one of them is 0.9 other one is 1.0??? Thank you for your videos.

@EEBADITYAPANDEY 3 жыл бұрын

the one which has 1.0 is more nearer to the electronegative atom so more deshielding (for 1.0 one) and so more magnetic field(or resonant frequency) is required.I hope that solves your doubt.

@amadiebuka8006 5 жыл бұрын

uR #Work is qreat

@amadiebuka8006 5 жыл бұрын

are we allowed to post videos too???

@stephaniepainchault2815 5 жыл бұрын

Why @ 15:00 is E it’s own signal? Does it not have an identical chemical environmental to D with two adjacent H’s?

@raanoooshh9296 5 жыл бұрын

I did not understand that one either. It's adjacent to secondary carbons as well ...

@raanoooshh9296 5 жыл бұрын

I think I just figured that one out lol. It's more distant from the oxygen, you could compare it to the example before and see why that one had carbons with the same environment.

@LadyShaydex 5 жыл бұрын

Yes but it's a carbon further away from oxygen than D. You can't just look at the close neighboring atoms, you have to look at the whole molecule.