Intermolecular Forces 2.5 - compare boiling points

[@musick4288]

Thank you! You made it easier to comprehend. Anyway, it's been 7 years, who's here in 2021?

[@lorodon4612]

Me

[@musick4288]

@@lorodon4612 hello! what course are you in?

[@lorodon4612]

11th standard

[@denisfrolov242]

Finally! Straight and logical explanation among entire tube. Thanks, well done!

[@ShayBean]

Denis Frolov Thank you for the feedback, it is really appreciated!

[@xBongWater]

If only my Chem teacher was this clear, i appreciate this alot! Thanksssss

[@ShayBean]

You are welcome! I"m glad it helped!

[@i_ezahshafique8971]

I was looking for this kind of lecture for 12hours

[@squanchmastersquanch4376]

Thankyou Mrs. Shay. You are a blessing. I just needed a quick recap.

[@ShayBean]

I am glad if it helped!

[@johnparks6936]

Wonderfully explained! I have just one question I was hoping you could answer: for the final example with H2O, H2S, and H2Se, why did we not take into account dipole moments when comparing H2Se and H2S? From what I understand, the Sulfur atom is more electronegative than the Selenium atom so it should follow that H2S have a stronger dipole moment than H2Se. And, according to your chart, dipole forces takes precedence over london forces (dipole > london) so shouldn't we consider that aspect first?

[@ShayBean]

+John Parks Thank you for the feedback! For your question, in general if you are comparing dipole forces among similar molecules, the differences won't be as large as the differences due to the London forces. The chart I provide gives you relative importance of the forces overall. In other words, if something has dipole forces, IN GENERAL it will have stronger forces than something that only has London forces, as long as you are comparing similar molecules. Once you are comparing molecules with the exact same set of forces, IN GENERAL the one with stronger London forces will win out. I hope this helps!

[@johnparks6936]

***** I see. Thank you so much for explaining!

[@larmisdor]

excellent job on all of your videos.

[@ShayBean]

Thank you! I appreciate the get feedback!

[@Ellie-qq9zm]

What about if you are comparing two molecules and one has hydrogen bonding but a lower molar mass than the larger molecule which only has dispersion? Then would you go by molar mass or by Hydrogen bonding? Let’s say the differences in molar mass are large.

[@yamackocovali8075]

How can I know if a molecule has polar forces?

[@coryretas2000]

omg this video is GREAT, thankyou!!!

[@ShayBean]

Glad it was helpful!

[@nouraalturki2723]

Wow finally I got it! It is so clear now 😍😍 thank you very much

[@hibahrehman9672]

for dipole-dipole forces how do you identify which one has a higher boiling or melting point. it is the number of electrons?

[@ShayBean]

I'm a bit late for this, but in general this works for similar compounds... more electrons = higher bp if have two substances with dipole-dipole forces. However, it can be more complicated that this... in General Chemistry I like to ONLY ask comparison questions on similar substances where more electrons gives you higher bp.

[@Ayy12366]

You really sound like my professor....the voice and the way you talk

[@ShayBean]

Chemistry instructors are all the same, eh?

[@dr_ilyaskhan]

yeah well thats what I want to know...excelllent job

[@ngalawena]

Well done! Thank you!

[@ShayBean]

Thank you!

[@tamta309]

such a good explanation,yet so little views

[@ShayBean]

+tom ta Thank you for the feedback, and I'm glad it helped!

[@haddadmj96]

So useful! Thank ya!

[@ShayBean]

Gloria Ha. You are welcome! I appreciate the feedback!!

[@itscake7]

Absolutely raddd

[@anitamehrdadian2387]

wait wait , Hbonding is not an intramolecular attraction " bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other."

[@ShayBean]

H bonding is an intErmolecular force or attraction. It is an attraction between two different molecules.

[@sukhamjotsingh3447]

Thank you

[@KiaBlessYoTrap]

Thank you so much

[@yashkapoor5894]

Wait.. i actually get this.. Im not that good at getting things

[@ShayBean]

Glad it helped, and apparently you are getting better at getting things, great!!

[@therealkarlcolt7116]

You explained in 8 minutes, what my prof made me read out of a book that made no sense. Finally makes sense 100%

[@ShayBean]

Glad it helped!!

[@Jessiemats]

Thanks!!

[@cestlavieeee]

I thought that if a molecule has H-bonding, its the largest and strongest IMF, so it would always have the highest boiling point? Teacher never talked about ionic, etc. Is this right? H bond always conquers? I have my exam under 24hrs!

[@ShayBean]

H bonding does TEND to be the strongest of the covalent molecule forces as long as the substances you are comparing are similar. Ionic substances TEND to have the higher boiling points, again, as long as you are comparing similar substances, but these will only be in ionic compounds. General chemistry instructors TEND to only ask you to compare similar substances, so I'm betting the H-bonding one will win in any question you get.

[@richarc2307]

👍🏽