The forces, either attractive or repulsive, that exist between molecules due to electric charge.

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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 ...
3
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45 views

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 ...
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42 views

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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66 views

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 its ...
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1answer
59 views

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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25 views

How would you know if … is H-Bond or Perm Dipole or Induced Dipole?

For example like HCl, why isn't it a Hydrogen Bond?
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Natural Bond Orbital (NBO) analyses: Physical significance/interpretation of E(2) 'stabilization energy'?

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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25 views

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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132 views

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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257 views

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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97 views

Why Tetrachloromethane has a higher boiling point than Trichloromethane?

London Dispersion Forces are present in all either polar or non polar molecules. Molecules also exhibiting Dipole-Dipole Interactions (in addition to the LDP) must have stronger forces of attraction ...
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83 views

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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217 views

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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68 views

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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67 views

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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1answer
229 views

Why does SiF4 have a higher melting point than SF4?

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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156 views

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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97 views

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 ...
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32 views

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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1answer
64 views

Reason for vibration of molecules

Why molecules of a body exhibit vibrational motion ? Is it due to interaction between various molecules of the body or inter atomic interaction of the same molecule? If it is because of any of them ...
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2answers
159 views

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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2answers
312 views

Why fluorine doesn't act as the central atom in inter-halogen compounds?

Why can't fluorine be the central atom in inter-halogen compounds? A $\ce{F-F}$ bond is weaker than a $\ce{F-X}$ bond and thus, fluorine should be happy to form inter-halogen compounds. But, why ...
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1answer
82 views

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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2k views

How to determine whether a compound is gas or liquid or solid?

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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68 views

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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130 views

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 ...
3
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2answers
403 views

Why do molecules having a higher $M_r$ have stronger inter-molecular forces?

Why do molecules like alkanes with higher molecular mass ($M_r$) have stronger inter-molecular forces? For example, methane ($\ce{CH4}$) has a weaker intermolecular force than pentane ($\ce{C5H12}$). ...
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1answer
143 views

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 ...
2
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1answer
101 views

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 ...
2
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1answer
394 views

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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1k views

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 ...
3
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2answers
82 views

Van der Waals question

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 ...
8
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3answers
12k views

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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200 views

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 ...