Conjugation and color | Spectroscopy | Organic chemistry | Khan Academy

Why extensively conjugated compounds absorb light in the visible region and thus have color. Created by Jay.
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Organic Chemistry on Khan Academy: Carbon can form covalent bonds with itself and other elements to create a mind-boggling array of structures. In organic chemistry, we will learn about the reactions chemists use to synthesize crazy carbon based structures, as well as the analytical methods to characterize them. We will also think about how those reactions are occurring on a molecular level with reaction mechanisms. Simply put, organic chemistry is like building with molecular Legos. Let's make some beautiful organic molecules!
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[@Jo24Park]

I've now known the effect of phenolphthalein for 10 years and never heard of that mechanism before. THIS IS SO COOL! :D

[@zubeyirozay2164]

This was the best explanation i have ever seen i my life!

[@andyposbe11]

really liked these transitions. no homo

good video, but i dont get which of the videos about this topic is the first one i should watch!!!!

[@briannahoff8589]

Why does the energy difference between the HOMO and LUMO decrease though? (other than that you've drawn them closer together)

[@anitalayal9171]

I want answer of this one ,,,I have same doubt ✌️

[@ahmednesartahsinchoudhury2628]

The volume is very low

[@cara.bella15]

Wait why are we focusing on only the pi bonds? Why not sigma bonds?

[@najgauner]

wow this was a great video... Even i as a high schooler with only basic knowlegde get it now

[@drgeetali]

Sound is very feeble in this video.

[@juliamo9755]

Omg thank you so much DX
I finally understood this topic

[@zestrus11]

When you say, "sp3 has no p-orbital, and sp2 has a p-orbital" Do you mean sp3 has no pi bonds and sp2 has one pi bond?
I thought sp3 has 3 p-orbitals and sp2 has 2 p-orbitals. Did you mean to say pi bond instead of p-orbital?

[@LUICT15]

+danielle lebouthillier i think what he meant was that sp3 does not have any unhybridized p atomic orbitals to form pi bonds while sp2 has 1 unhybridized p orbital and can form a pi bond

[@manzoorahmeds7567]

hi

[@jojolili8764]

Why is the reduced form of DCPIP colorless but the DCPIP blue?

[@agathaknive3321]

THIS IS EXPLAINED SO WELL OH MY GOD WHY CAN'T YOU BE MY CHEM TEACHER

[@h7opolo]

0:03 wrong. wtf r you talking about?

[@evelynakow6771]

wonderful explanation thank you!

[@agent475816]

What if you re-acidify the phenolphalein. How would it go back to its original structure? Wouldn't you get an alcohol on the O- and end up with a carboxylic acid on the COO-? Then it would still be pink.

[@Jo24Park]

basically possible and it will also happen. But only in equilibrium with the formation of H2O. Remember that this is an effect in the absence of H ions. So either H2O or OH/COOH but not both simultaneously. And I'd guess that because OH- ions are just smaller they get H+ more easily than the sterically hindered phenolphthalein.

[@seanpeters8551]

this helped so much, thank you!

[@MEBSAMPATHKUMARKODI]

When a compound is subjected to electromagnetic radiation why cant it absorbs all radiations like microwave , ir, and uv and emits light in visible region?

[@fakhrulnawawi9681]

VERY VERY NICE VIDEO..THANKS A LOT

[@amilasandaruwan7583]

thanks for the help! (y)

[@31rifahnoorchowdhury19]

why is the energy difference smaller ?

[@nicolasvelez1099]

can anyone tell me how spectroscopy is used in real life? I don't get this subject :(

[@km-sc4kz]

Spectroscopy is used to identify molecules by looking at their absorption spectra.

[@brayanelian6905]

Thanks for the explanation

[@pawanjandu4285]

Sir app kis app se videos bnte ho

[@georgeclooney9164]

Ok, So i understand the concept of absorbing a specific wavelength of light, but hwo do we get it reflecting a different wavelength? Is there another formula that dictates what wavelength is emitted from a molecule based on what that molecule absorbs?
Thanks!

[@Nicolas-eo7lo]

This might be a bit late, but as far as i understood it: If a material is lets say red, then every wavelength is absorbed by this material, EXCEPT red/reddish wavelengths which are reflected into your eye. Can anyone verify this?

[@ghostsniiper1]

@@Nicolas-eo7lo Not quite, lets see a molecule absorbs red wavelength of light. The light reflected will be the complementary colour according to the colour wheel, in the case of red light being absorbed the complementary colour is green and so the compound wil be green coloured.
Hope this helps

[@pawelino134]

Great explanation, great teacher!

[@sheetalmore2052]

I love you.. You always help me a lot.. 😭😭

[@mnswz3140]

thanks so much

[@anitalayal9171]

Wowwww✌️