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

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Why not an Avogadro's principle for solid matter?

Avogadro stated that for any ideal gas, 1 mole of particles will occupy a specific volume at a specific ratio of pressure and temperature. So why doesn't this apply to a liquid or solid?
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2answers
51 views

Fundamental physical forces behind osmosis

I wonder which fundamental forces act behind osmosis process? Sum of these forces oppose gravity force, like in this figure: So I wonder what are these forces?
4
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1answer
45 views

Bending of water and methanol towards a charged objects

I just had a question about why does water, methanol or any other polar substances tend to bend towards the charged object. I think it is because of a slight dipole dipole movement between the ...
8
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1answer
128 views

Is an ionic bond more like a covalent bond or an intermolecular force?

I have asked a question loosely asking this, where I confused terms and did not specify what I wanted to know here, so I formed a new question. What are the differences and similarities between ionic ...
7
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1answer
107 views

How to read TINKER's force field parameters

I'm going to parameterize AMBER force field for the simulation of some small molecules. I have found the parameter sets provided by TINKER at here. I'm stuck here because I couldn't find any ...
10
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3answers
123 views

Strength of hydrogen bonding in phenol or methanol

I wanted to know whether hydrogen bonding is stronger in phenol or methanol. I saw on Wikipedia about the enthalpies of hydrogen bonding in various cases. but could not find the answer to this ...
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0answers
47 views

How to determine if a compound is likely to become a solid at room temperature?

Reasoning: My guess would have to be that it has to do with the strength of the intermolecular forces between each molecules. Take for example, molecular compounds that have a very low molar mass like ...
6
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4answers
620 views

Why is CF4 non-polar and CHF3 polar?

This question is a bit tricky to me because of the following: Take in consideration these two molecules: $\ce{CHF3}$ and $\ce{CF4}$ These are their Lewis dot structure: $\ce{CHF3}$ $\ce{CF4}$ ...
5
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2answers
56 views

Why is there a greater degree of separation in a dipole-dipole interaction?

My textbook says this: Electrostatic forces between two ions decrease by the factor $\frac{1}{d^2}$ as their separation distance, $d$, increases. Dipole–dipole forces, however, vary as ...
6
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1answer
79 views

Intermolecular and Intramolecular Forces (Vapor pressure of n-butylamine and methanol)

What are the different properties that intermolecular forces and Intramolecular forces attribute to? i.e. intermolecular forces contribute to BPs, vapor pressures, etc. Specific problem: why does ...
6
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1answer
216 views

Why is a ketone not capable of hydrogen bonding among themselves?

The ketone has one oxygen atom in it and there are two lone pairs hanging out, both of which make it seemingly capable of hydrogen bonding. But in reality it is not. Did some research and found ...
4
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1answer
38 views

Charge consistency in fragment qm/mm methods

I'm calculating the multipole moments on several fragments of a molecule. What are some procedures to ensure that the charges etc are representative of the complete molecule? How do I ensure I'm not ...
5
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1answer
409 views

Intermolecular Interaction

The Inter molecular interaction that is dependent on the inverse cube of distance between the molecules is: Hydrogen Bond ion-ion interaction ion-dipole interaction London Force My thinking: ...
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0answers
15 views

What radius best represents reaction distance?

Molecules must be within a certain distance for a reaction to begin as well as satisfying a myriad of other factors. Whilst the exact distance varies from reaction to reaction, is their any ...
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1answer
86 views

Interpreting a Phase Diagram?

The correct answer (that is false) is A) however can someone please explain why the other options would be true and why it is in fact possible to compress a solid to produce a liquid?
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2answers
32 views

Interaction radius of a molecule

What is the most commonly used radius of an atom or molecule to describe the area that must touch another area of another molecule for the two to react. Is there one radius that always works or does ...
4
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1answer
2k views

Alkane, Alkene, Alkyne boiling point

I'll be having a national test tomorrow. I'd like to clarify so that I don't answered it wrong. Question: Which of the following has higher boiling points? Alkanes, Alkenes, or Alkynes? And why? ...
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0answers
32 views

How do you know what inter-molecular interactions are present?

I'm studying for a chem exam and there are often questions of this form: What kind of inter-molecular interactions are important in (insert compound here). Then the possible answers are any ...
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0answers
29 views

Is the momentary dipole in between a cell membrane due to the van-der-Waals forces?

There are van-der-Waals forces within non-polar molecules. I read it that is mainly due to the instantaneous movements of the electron cloud's distribution. When looking at symmetrical molecules like ...
2
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1answer
62 views

How to get a protein's dihedral angles ordered by variance?

The setting: I want to simulate protein docking and let some dihedral angles vary, but in order to keep it low-dimensional I have to select those which are most likely to change. What I've thought of ...
4
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1answer
65 views

What forces keep a cotton fiber together?

According to Wikipedia, a single cellulose molecule is: a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. which means a cellulose molecule ...
4
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1answer
68 views

Why are C6 dispersion forces named C6?

I'm reading about water models and their dispersion coefficients, and going back to S. C. Wang's work according to the citation of an equation (Google books here) As you can see one citation's to a ...
2
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1answer
97 views

What is the reason for this azeotrope formation?

What is the reason for the formation of an azeotrope? I mean why with certain compositions, one component alone cannot go to vapour phase. Is there any extra force holding the two components together? ...
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1answer
53 views

When the intermolecular forces in a liquid increase, does the equilibrium vapor pressure of the liquid at a given temperature increase or decrease?

I assumed it would increase, but I think I am wrong. I know that when the forces are strong, the vapor pressure would decrease. Does this same principle apply to the IM forces increasing?
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1answer
115 views

What forces hold ink on paper?

On regular paper, ink is absorbed, while on photopaper ink stays at the surface and dries for a longer time. What forces act in these two different cases? (see also related questions about pencil ...
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2answers
59 views

How to rationalise the difference in the melting points of acids and alcohols with inter molecular forces?

Acids: arachidic acid, palmitic acid, lauric acid, etc. Alcohols: butan-1-ol, pentan-1-ol, etc. The melting points of acids with $\ce{-COOH}$ at the end compared to melting points of alcohols, ...
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1answer
35 views

Is there a clear distinction between the various intra- and intermolecular interactions?

Wikipedia lists dipole-dipole, hydrogen bonding and Van der Waals under intermolecular interactions, and hydrophobic, ionic and covalent under intramolecular interactions. Is there a clear ...
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2answers
61 views

Structures present in liquid water

I know this may be a too generic question, but here it goes anyway. It is already know that solid water (ice) organizes its molecules in a lattice (in a variety of 16 different crystals and one ...
3
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1answer
180 views

How are pencil marks “adhered” to the paper?

Pencils create marks by physical abrasion, leaving behind a trail of solid core material that adheres to a sheet of paper or other surface. Wikipedia Normal paper is mainly composed of cellulose ...
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1answer
110 views

the strongest intermolecular forces between hydrogen bromide and potassium permanganate? [closed]

the strongest intermolecular forces between $\ce{HBr}$ and $\ce{KMnO4}$? Is $\ce{HBr}$ polar nonpolar or ionic? how about $\ce{KMnO4}$?
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2answers
49 views

What's the reason for discrepancy between DFT calculated image and NC-AFM-acquired one in this article?

Looking at the images in this article, I've noticed that the molecule electron density images showed as calculated via DFT look very symmetric, while those obtained by NC-AFM appear somewhat ...
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1answer
48 views

Entanglement of large molecules

In many textbooks and chemistry curricula, we can see the description of large molecules (particularly in the discussion of hydrocarbons and other nonpolar compounds) as having "entanglement." ...
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3answers
252 views

Why does capillary action occur better in narrow tubes than in wide tubes?

We all have seen the meniscus of a small graduated cylinder in the lab. The reasons for the occurrence of capillary action are clear, but why does it occur more profusely in smaller-rimmed containers? ...
4
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1answer
45 views

Halogen bond definition

I was looking for an accurate definition of halogen bonding. I was able to find quite a few good ones, but none of them would explain if a X---H intermolecular interaction would count as a form of ...
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2answers
175 views

Factors of London Forces

In class we learnt that the London forces become stronger as the relative molecular mass increases. Not just as in organic chemistry but in things like the halogens. However, as I understand, the ...
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1answer
59 views

how protons(H+) react with matter and cause the solution to be acid?

For example if my hands were put in a HCl solution how does the protons in the solution which in high amounts will interfere/react with my hand(skin->proteins..) and cause it to burn...or how protons ...
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2answers
1k views

How do I figure out the relative polarity of organic compounds?

It's a question on my quiz which I guessed right and couldn't do the reasoning: Based on the intermolecular forces, predict the boiling points of the following substances and list them in the ...
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2answers
325 views

Intermolecular forces in Carbon Nanotubes?

What are the intermolecular forces that can be found in Carbon Nanotubes?
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0answers
46 views

Finding physical properties of epoxide groups

I have a project (12 Chemistry) that asks to talk about the physical properties of epoxide groups. This includes the boiling/melting point of epoxides as well as what intermolecular forces are at play ...
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1answer
956 views

Does hydrogen bonding only occur between water molecules?

Does hydrogen bonding only occur between water molecules? Is the dipole-dipole intermolecular interaction know as hydrogen bonding because it is between water molecules, or is called that because of ...
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1answer
94 views

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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1answer
94 views

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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2answers
4k views

Which compound has the highest melting point?

Which of the following compounds has the highest melting point : $\ce{PCl5}$, $\ce{H2O}$, $\ce{NaCl}$, $\ce{SrCl2}$, $\ce{CaF2}$? I've asked a question concerning the boiling points and I got an ...
5
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2answers
8k views

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: $\ce{CO2}$: ...
2
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0answers
151 views

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 ...
5
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2answers
675 views

is this statement always true? : The more -OH functional groups in the molecule, the more is its viscosity

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 ...
3
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1answer
2k views

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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1answer
112 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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1answer
257 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 ...