Questions tagged [intermolecular-forces]
The forces, either attractive or repulsive, that exist between molecules due to electric charges or varying electron cloud distribution. This tag could also include intra-molecular attractions (within one molecule itself) often found in a protein amino acid residues.
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Intermolecular forces in Carbon Nanotubes?
What are the intermolecular forces that can be found in Carbon Nanotubes?
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How does sugammadex (a modified cyclodextrin) draw rocuronium into its lipophilic cavity?
Sugammadex is a modified cyclodextrin: 8 member sugar ring with carboxyl thioether extensions. Rocuronium is an aminosteroid, 4 steroid rings and one protonated amine group.
Sugammadex binds ...
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Why is the difference in boiling point so much greater between methanol and methane than it is between 1 decanol and decane?
So any data sheet will tell you;
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Bond Angles and intermolecular interactions
It's fun to consider bond angles of molecules in isolation. For example, what is the number of different bond angles exhibited by the most polar form of $\ce{SIBrClF2}$?
However, can bond angles ...
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How to calculate which ionic compound has the highest melting point?
Which of the following compounds has the highest melting point: $\ce{PCl5}$, $\ce{H2O}$, $\ce{NaCl}$, $\ce{SrCl2}$, $\ce{CaF2}$?
In general, ionic compounds will have higher boiling points than those ...
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Arrange these compounds: CO2, CH3OH, RbF, CH3Br in order of increasing boiling points
Arrange these compounds: $\ce{CO2}$, $\ce{CH3OH}$, $\ce{RbF}$, $\ce{CH3Br}$ in order of increasing boiling points.
I think I should consider the forces between them, that is:
$\ce{CO2}$: dispersion ...
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Structure of fluoroalkylsilane
I want to use FAS (fluoroalkylsilane) in my molecular dynamics study. How can I find it's real structure? So that I can find proper forcefield for simulating the molecule. It would be very nice if you ...
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Is viscosity proportional to the number of hydroxyl groups?
Is the following statement always true?
The more $\ce{-OH}$ functional groups in the molecule, the more is its viscosity?
I think it is true, because it is known that weak intermolecular forces ...
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Why doesn't the viscosity of water change much with temperature like it does for other substances?
I would like to know why water doesn't ever become like syrup before it freezes when many other liquids, such as hydrocarbons, seem to have a more gradual change from becoming more viscous and then ...
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Van der Waals Radius clarifications
I just read about van der Waals radius and had some questions about it.
Would it be correct to say that in general, van der Waals radius decreases as we move from left to right in the periodic table? ...
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What is the difference between a bond, force, and interaction?
I am trying to explain why some solids are more soluble in water than others.
So the energy released from the formation of bonds between the solid solute molecules and water molecules compensate the ...
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Why do ionic substances with higher lattice energies tend to be less soluble in water than substances with lower lattice energies?
I understand that that energy is required to overcome intermolecular forces holding solute particles together in the crystal, but I don't understand how this relates to lattice energies and respective ...
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How does intramolecular hydrogen bonding cause the molecules to be separated from each other?
I learnt about intramolecular hydrogen bonding today, which occurs between molecules such as ortho-nitrophenol. What I was told is that in case of intramolecular bonding, the molecules separate from ...
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Homoassociation and Acid Strength
I understand that the strength of HF differs significantly depending on the concentration. I understand the basic theory behind this - homoassociation - and stabilization of the highly negative charge ...
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How would you know if ... is H-bond or permanent dipole or induced dipole?
For example like HCl, why isn't it a hydrogen bond?
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Natural Bond Orbital analysis: Significance of stabilization energy determined by 2nd order perturbation
PREFACE: I am no expert on this topic. My questions at the bottom may be off base. I have some experience with symmetry-adapted perturbation theory (SAPT) when it comes to analyzing intermolecular ...
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Why is mass proportional to the strength of a dipole-dipole attraction? meaning more mass more strength [duplicate]
I don't understand why the mass of a molecule make it attract more to other polar molecules.
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What's the relationship between Van der Waals forces and hydrophobic interactions?
A question on a past exam for a course I'm studying for asks:
What's the relation between Van der Waals forces and hydrophobic
interactions?
From what I understand, Van der Waals forces are ...
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What type of intermolecular forces will dominate Diethyl ether?
Is Diethyl ether (also known as ethyl ether) a polar molecule? What type of intermolecular forces dominate it? Dipole-Dipole Interactions, London Dispersion Forces or Hydrogen Bonding? Please Explain.
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Why does tetrachloromethane have a higher boiling point than trichloromethane?
London dispersion forces (LDF) are present in all molecules, whether polar or non-polar. Molecules also exhibiting dipole-dipole interactions (in addition to the LDF) must have stronger forces of ...
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Why Isodecane (B.P.: 327 *C) has a higher boiling point than decane (B.P.: 174.1 *C)?
Branched chain molecules have lower boiling point than straight chain molecules because branched chain molecules have a smaller surface area where they can be attracted by other molecules. Then, why ...
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Why don't molecules of ionic compounds exist?
My book says:
As single ions of a metal are not associated in the solid with single ions of a non metal, separate units of ionic compounds do not exist. It is, therefore, wrong to talk of a ...
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Determine which molecule has stronger intermolecular force?
SiH4 and CH4
The only intermolecular force they both have is London Dispersion forces
Strength of LDF is determined by molar mass
molar mass of SiH4 = 32.132
molar mass of CH4 = 48.42
Therefore ...
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Why Ionic compounds dissolve into water
First, I would like to say that I understand the basic idea of disassociation and solubility. However, as I study intermolecular forces I feel like this basic Idea is being challenged. My ...
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Why does silicon tetrafluoride have a higher melting point than sulfur tetrafluoride?
So looking at the Wikipedia pages of sulfur tetrafluoride and silicon tetrafluoride, the melting points are −121 °C and −90 °C respectively, and so $\ce{SiF4}$ has the higher melting point. However, ...
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Van der Waals nonspecific interaction definition
Every definition I see of Van der Waals interactions claim that they are short-range, nonspecific interactions between two chemical species. What does "nonspecific" mean in this context?
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Intermolecular forces in secondary amines compared to primary amines
Secondary amines form hydrogen bonds, but having nitrogen in the middle of the chain rather than at the end makes the permanent dipole on the molecule slightly less. The lower boiling point is due to ...
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Hydration of lithium salts
Why are lithium salts heavily hydrated? I am not able to understand this because I feel salts of larger cations like Caesium should be more hydrated because of the larger size, they can able to hold ...
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Reason for vibration of molecules
Why do molecules of a body exhibit vibrational motion? Is it due to interaction between various molecules of the body, or interatomic interactions between atoms in the same molecule? If it is because ...
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How does molecular structure affect physical properties?
The question sounds vague and non-specific because my background in chemistry is limited to undergrad college courses. However, I am interested in learning the correlations between the atom-by-atom ...
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Which d-orbitals split according to CFT?
According to CFT, the degenerate d-orbitals split into $eg$ and $t_2 g$ groups. Are these the outermost nd orbitals which are vacant(4-d in case of 4th period) or the penultimate filled (n-1)d ...
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Do superhydrophobic/hydrophobic materials generally have a lot of friction or only a little friction
Also, are there any exceptions that you know of?
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Critical separation at which molecule breaks
I have the following question.
The potential energy of two atoms, a distance $r$ apart, is: $$U = -Ar^{-2} + Br^{-10}$$ Given that the atoms form a stable molecule at a separation of $\pu{0.3 nm}$ ...
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How to determine whether a compound is gas or liquid or solid? [closed]
My book says, methyl chloride, methyl bromide, ethyl chloride and some cholorofluromethanes are gases at room temperature, whereas higher members are liquids or solids. Why?
With this question, I ...
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Coarse-grained force field for ion–water interactions
I want to simulate, at a very coarse grained level, the interaction of water molecules with metal ions, specifically Calcium and Potassium. Is there a standard force field for this. I was told to use ...
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Gold nanoparticles in a water/oil environment
I am currently investigating the assembly of gold nanoparticles in a mixture of water and oil. The thing is the following: If we have gold nanoparticles (35nm diameter) dispersed in water and we put ...
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Why do molecules having a higher relative molecular mass have stronger inter-molecular forces?
Why do molecules like alkanes with higher relative molecular
mass ($M_\mathrm r$) have stronger intermolecular forces? For example, methane ($\ce{CH4}$) has a weaker intermolecular force than pentane (...
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Why are the vinylic bonds in alkenes slightly polar?
when searching in the internet about why are alkenes more polar than alkanes (but still they are non-polar), they are always saying that the double bond is more polarizable , i understood the whole ...
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Questions about intramolecular interactions in AMBER forcefield
I am trying to run a molecular dynamics simulation with AMBER forcefield. However, it's the first time I use is, and while I know the form of the various intra- and intermolecular energy terms, some ...
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Do metallic bonds contain London dispersion forces?
On our chemistry exam, a question asks "Which force is present between Fe particles? a) Van der Waals b) Metallic"
At first it seemed obvious that it was metallic; however, upon closer reading, it ...
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Why do single, double and triple bonds repel each other equal amounts?
I'm here to share with you something that totally confuses me, as I can't see the logic behind it, and my teacher doesn't know either.
Let's take a set of bonds that's trigonal pyramidal, with a lone ...
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The effect of structure on the boiling points of organic molecules
Why do molecules like methoxyethane, ethoxyethane and so on have lower boiling points than isomeric alcohols?
I think it has something to do with the structure, but I don't exactly know what it is.
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When considering Van der Waals forces, why do dipoles form?
Imagine two atoms, and only consider the Van der Waals force. The electron cloud will jitter due to its quantum mechanical nature- some of these jitters forming dipoles, some not. However, on average ...
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How do non-polar substances dissolve in non-polar solvents?
The case of polar solvents is clear to me - we get an attraction between opposite charges. However, how do non-polar substances dissolve in non-polar solvents? How could it be explained on a molecular ...
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Why are equations of state for a non-ideal gas so elusive?
The ideal gas equation (daresay "law") is a fascinating combination of the work of dozens of scientists over a long period of time.
I encountered Van der Waals interpretation for non-ideal gases ...
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Are buckminsterfullerene-corannulene complexes actually stabilised by π stacking?
According to wikipedia and the references given therein, $\pi\cdots\pi$ stacking interactions are the result of interaction between the quadrupole moments of two aromatic rings, rationalising the ...
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