Types of Intermolecular Forces

[@darkmoon3646]

U r a freaking legend mr machem guy.

[@RuhabDabeer]

Really Helpful Video It got me understanding this tough topic Also the iodine structure look like grapes

[@rafiatbm7867]

Sir, 2 questions... Q:1 Can you elaborate up a little bit more about the the London forces in molecules?? At around 5:43 , Is the electron clouds of of the two atoms forming covalent bonds between each other gonna superpose like that and electrons will be able to freely move along the entirety of it?? If that's so, can you explain up a little bit more about this kind of effect as I'm not being able to wrap around my head regarding this... Q2: Does the asymmetry in oscillation of electrons within their orbital occurs just like that , Oooorrr is it because in covalent molecules the bond pair of electrons tend to oscillate from the mean central position within the bonded atoms?? Suppose Br2 molecule is Br(1)--Br(2).. What I think is happening is that due to the oscillation of their bond pair of electrons, at one instant the bond electron pair oscillates and go towards Br(2) which makes the Br(2) electronegative and Br(1) electropositive... And this happens because the orbital electrons of Br(2) got shifted towards the other side(i.e. its right side) due to the electrostatic repulsion between the Br(2)'s orbital electrons and the bond pair of electrons and thus the electron density got increased there..Is this what happens?? (This is what I wanted to ask in Q2)... Then I'm confused at exactly what way the polarisation took place...Does it form superposed electron cloud like that and overall electrons oscillate within the entire superposed atomic orbitals , and overall one side have more electrons, making it delta- and vice versa happening to the other side ?? (This is what I wanted to ask in Q1)....

[@mikethomas6009]

Do you have a photo of the set up please?

[@sineadryan4424]

I was just answering a multiple choice question which asked 'Which bonds or interactions are responsible for the higher boiling point of hydrogen iodide compared to hydrogen bromide?'. I selected 'permanent dipole dipole interactions' because as it says in this video - HI has permanent dipoles. However the answer was induced dipole dipole interactions and I've read the textbook, my class notes and have watched your KZbin videos and I still don't understand. Please could you explain it to me? Thanks so much

[@toska7922]

9:08 will explain it

[@sineadryan4424]

T x but that talks about the halogen as a halogen rather than as a halide? HBr has a permanent dipole dipole whereas Br2 has induced dipole dipoles? (Thanks for responding!)

[@MaChemGuy]

Don't forget that all molecules have induced-dipole dipole forces between them too. In the case of the HI molecule, its greater number of electrons mean that it has strong induced-dipole dipole forces thus raising its boiling point above that of HBr

[@sineadryan4424]

MaChemGuy ohhh okay that makes a bit more sense...but how do you know if it's the induced or the permanent dipoles that are responsible? Is it because the difference in induced dipole interactions in HI and HBr affect the boiling point? How come the permanent dipoles don't affect it/aren't affected down the group? (If that makes sense?)

[@MaChemGuy]

In this specific example, we know that the H-I bond will be less polar than H-Br due to electronegativity trends. So if the boiling point of HI is higher than that of HBr it has to be down to the induced dipole-dipole forces being stronger.

[@rosaalnds]

hi , doesnt everything have a dipole then , like everything will have either a delta - or a delta + charge ? also i dont quite exactly understand what a dipole dipole interaction is , like how would you know if something is polar ? thanks

[@ksi800]

in london forces does the intermolecular force disappear and appear since electrons are constantly moving?

[@abdihogsade47]

thnks

[@ksi800]

b2 is a liq and i2 is a solid?? thought that were gases

[@RuhabDabeer]

In room temperature which is about 20 Degrees Br is Liq and Iodine is Solid