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

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57 views

Why are Chiral Molecules such a big deal? [closed]

Today, I came across the discovery of a Chiral Pair in interstellar space. I know that A chiral molecule is a molecule that is not superimposable on its mirror image. But why is it such a big deal? ...
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28 views

In dsDNA which force is stronger, base stacking or hydrogen bonds?

I've seen many articles that state that hydrogen bond (2 to 3kTs) is stronger than base stacking, but lately I got into Sponer's article 'Nature and magnitude of aromatic base stacking in DNA and RNA' ...
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2answers
23 views

Why are bonding interactions so much stronger than interactions of other types?

Why are bonding interactions so much stronger than all the other types of interactions like dipole-dipole, London dispersion, hydrogen bond etc. even though they are all of electromagnetic origin?
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26 views

Water has H Bonds?

So I'm studying for a chemistry test and one of the practice problems is "What is the intermolecular force present in water?" We made handy flow charts for this and so I determined that it was polar. ...
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60 views

Why is the boiling point of pentane (36.1C) slightly higher than that of diethyl ether (34.6C)?

Both are chains of the same length, except diethyl ether has an oxygen atom in the middle instead of a carbon. Diethyl ether has a slight dipole from the oxygen atom, so shouldn't the intermolecular ...
2
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1answer
85 views

Why do alcohols and ethers have approximately the same solubility in water but different boiling points?

In Morrison & Boyd, I found this question: Butan-1-ol (b.p. $118~\mathrm{^\circ C}$) has a much higher boiling point than its isomer diethyl ether (b.p. $35~\mathrm{^\circ C}$), yet both ...
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0answers
38 views

Intermolecular Forces in Teflon vs Polyethylene

From Wikipedia, polyethylene has a melting point of around $400K$, while Teflon (polytetrafluoroethylene) has a melting point of $600 K$, which is much higher. Besides the increased London Dispersion ...
2
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1answer
87 views

Why are naturally occuring liquids more rare than solids and gasses on Earth? [closed]

There are only a few naturally occurring liquids I can think of on earth, such as water, mercury and animal oils. Why are naturally occuring liquids more rare than solids and gasses on Earth? To be ...
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1answer
40 views

Model of London forces and Hydrogen Bonding; the question is carried on forward, partially, as a personal question, from another question [closed]

Does Model of London forces and Hydrogen Bonding are themselves complicated and require multiple sub-models and assisted theories to explain its correctness. I asked this question in the form (...
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1answer
26 views

Dispersion forces - what determines which molecule will have its electron cloud repelled?

Here is an image I found which illustrates dispersion forces: One helium has its electron cloud repelled by the other helium's electron cloud, which exposes the nucleus and gives an induced dipole ...
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0answers
57 views

What are the different types of van der Waals forces?

As per different websites on internet van der Waals force are of Three types (Keesom force, Debye force and London dispersion force) @ Wikipedia Two types (Dipole-dipole force/Keesome force and ...
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49 views

Interactions between water and oil

I haven't thought about the forces that attracts oil to water (it is weak). The attractions between water molecules are caused by hydrogen bonds (primly), while oil through London forces. But between ...
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0answers
131 views

which has stronger intermolecular dipole-dipole forces? SCl2 or CO?

The title sums up my question. I used electronegativity values to get the EN value for each bond ($\ce{C - O}: 0.89$, $\ce{S - Cl}: 0.58$). However, there are two $\ce{S-Cl}$ bonds in the $\ce{SCl2}$ ...
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2answers
60 views

Correlation between functional group and viscosity of an organic compound?

I'm looking to explore the correlation between the type of functional group on an organic molecule and the viscosity of the compound. I know that viscosity is affected by intermolecular forces (Ion-...
5
votes
0answers
77 views

Is Van der Waal's force the real source of friction?

I'm currently taking a physics class, and my teacher explained that friction is the result of intermolecular interactions, and that energy must be applied in order to break these bonds. This got be ...
3
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1answer
33 views

What causes straight fatty molecules to form a lattice (e.g. saturated fats)?

What causes multiple chains of saturated fats to pack together and form a solid? It is said that because the chains are straight, they form a lattice and line up more easily. But if I had a bunch of ...
0
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1answer
52 views

Trying to understand the causes and implications of kinks in fatty acid chains

I watched this video (The Deal with Fat by SciShow): https://www.youtube.com/watch?v=mvvx2yQRbzQ To summarize the main points I want to discuss: Saturated fats are chains without any double-bonds ...
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0answers
37 views

Strength of London Dispersion Forces - Why do rings have stronger dispersion forces? [duplicate]

My textbook says, Rings can be stacked on top of one another to give rise to stack of closely spaced rings, hence they have overall stronger dispersion forces. Ring > Linear > Branched With similar ...
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1answer
81 views

How to calculate Madelung's constant for NaCl?

Madelung's constant for $\ce{NaCl}$ is $1.748$. What I tried to so is sum up all the individual interactions into $1$ component where the $X$s are the nucleus and the electron if it was a $2$ atom ...
7
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1answer
122 views

How does fluorouracil inhibit thymidylate synthase?

I'm curious to know how just by adding a fluorine atom to uracil (to form 5-fluorouracil) permanently inhibits the enzyme thymidylate synthase when they bind together. This molecule is widely used as ...
2
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0answers
18 views

Solvation rates of crystalline and noncrystalline materials

Assuming equal surface area (and other variables), would a highly ordered crystal of some substance dissolve more slowly or quickly than (or at the same rate as) a disordered sample of the same ...
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0answers
79 views

Does ion dissociation affect things such as molality, molarity, mole fraction, etc.?

One of my homework questions (see image) asks us to calculate the molarity, molality, mole fraction, and mass percent of the solutes of various mixtures. The question includes the remark "Remember to ...
4
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1answer
82 views

Ordinary differential equation for molecule collision

My knowledge is 0 in chemistry. But, I have a good background in mathematics and computer programming. I have planed to simulate the collision of two simple molecules $\ce{Br2}$ and $\ce{H2}$ just ...
2
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0answers
425 views

Why does CO2 have higher boiling point than CO?

The intermolecular forces between $\ce{CO2}$ molecules are dispersion forces, while the forces between $\ce{CO}$ molecules are mostly dipole-dipole attraction forces. So, why does $\ce{CO2}$ have a ...
4
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1answer
98 views

Why plastic sheets contract when heated?

Why do thin plastic sheets contract when heated, contradictory to the behavior of most other materials ? What are the things going on at the molecular level ?
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0answers
63 views

Boiling point and Intermolecular forces

After looking for proper reasons for boiling point orders, nobody could even explain why $\ce{CCl4}$ has a higher boiling point than $\ce{SiCl4}$, but after looking for patterns, in lots and cases of $...
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0answers
28 views

Are heterolytic dissociations barrier-less or do they have an activation energy?

When a bond is broken into ionic fragments, and I'm specifically thinking about organometallic or coordination chemistry, the two products carry opposite charges and the potential energy curve should ...
2
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0answers
171 views

Why does chlorine have a higher boiling point than hydrogen chloride?

Chlorine has a boiling point of $238~\mathrm{K}$ while hydrogen chloride has a boiling point of $188~\mathrm{K}$. Hydrogen chloride has dipole-dipole forces so I would expect it to have greater inter-...
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54 views

High Viscosity of Noble Gases

Why are the viscosities of noble gases higher than almost all other gases? This seems counter-intuitive since they have much weaker inter-molecular interactions and lower boiling points. Gas ...
4
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1answer
113 views

Trend in the boiling point of the hydrogen halides

The boiling points of the hydrogen halides are as follows: $$\begin{array}{cc} \hline \text{Species} & \text{Boiling point / }\mathrm{^\circ C} \\ \hline \ce{HCl} & -85.1 \\ \ce{HBr} & -...
4
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0answers
81 views

Why do chlorinated silanes have lower boiling points than their methane analogs?

The boiling points of the chlorinated silanes and methanes are given below: $$\begin{array}{ccc} \hline \text{Species} & \text{Boiling point (X = Si) / }\mathrm{^\circ C} & \text{Boiling ...
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1answer
258 views

Why is the boiling point of CH3COOH higher than that of C2H5OH?

Why is the boiling point of $\ce{CH3COOH}$ higher than that of $\ce{C2H5OH}$ ? Both are polar molecules held by hydrogen bond.
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Can nonpolar molecules exhibit dipole-dipole forces?

Dipole-dipole forces occur when the positive part of a polar molecule is attracted to the negative part of a polar molecule. In a nonpolar molecule, there may still be polar bonds, it's just that the ...
4
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0answers
69 views

Calculating volume ethanol in an fermented aqueous solution of sucrose, water, and ethanol

I've been working on a biology experiment where I calculate the fermentation yield of yeast under various light induced stress responses inhibiting the translation of various fermentation enzymes. My ...
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1answer
85 views

What is the connection between vapor pressure and intermolecular force explanations of boiling?

I've had boiling explained to me in two ways, and I'm having trouble understanding how they connect. The first way is that a liquid is held together by the intermolecular forces, and boiling involves ...
0
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1answer
102 views

Are the collisions between the real gas particles perfectly elastic?

Well my question is simple, if two real gas particles are colliding (head on collision) then will the kinetic energy will be conserved i.e. will it be a perfectly elastic collisions?
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1answer
83 views

How to save the force on a molecule in GROMACS?

I am a new student of molecular dynamics. I have started using GROMACS since one month. I have a small box of 8192 molecules each with 3 atoms. I have frozen the last molecule and run the simulation. ...
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3answers
443 views

H2Te dipole and electronegativities of H and Te (high school level chemistry)

I saw somewhere that $\ce{H2Te}$ is a polar molecule, but as far as I know the only time dipole-dipole forces arise (giving molecules the possibility of becoming polar) are when there is a difference ...
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1answer
136 views

Why are noble gases 'gases'?

Why do group 18 elements exist as gases, why are they not found in any other physical state ?
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0answers
15 views

Would graphite stick to basalt cooled from its molten state in a graphite mold?

Molten metal that is poured into a graphite mold pops out easily once it has cooled. Would basalt poured the same way pop out just as easily? I am particularly interested in lunar basalt, if that ...
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1answer
51 views

London Forces and Liquifying Noble Gases

From my book, it says that 'without van der Waals (London Dispersion) forces, it would be impossible to liquefy noble gases.' Why is this the case?
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0answers
83 views

What happens to the attraction of glycerol to a positively charged acetate rod if water is added

I know that glycerol is more polar than water because it has stronger intermolecular forces and its also more viscous. If I were to add water to a glycerol solution, would the solution get less polar ...
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1answer
93 views

Why the boiling point decreases with increase in branching in alkyl groups?

I found out its answer that with increase in branching, the molecules attains a spherical shape with less surface area. As a result, interparticle forces become weaker resulting in lower boiling ...
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0answers
50 views

Why do cohesion and adhesion increase with smaller powder particles?

I am wondering why cohesion and adhesion increase when one would decrease particle size of a powder mixture. I've searched on google a bit but can't really find an explaination and in my textbook it ...
2
votes
2answers
1k views

How does a water molecule bond to an anhydrous salt to form a hydrate?

Some sites suggest that water molecules bong to anhydrous salt via a "loose bond". What does that even mean? $\ce{H2O}$ is a polar molecule and salts are made up of ionic bonds. Is it a hydrogen bond ...
2
votes
1answer
344 views

Why is Iodine's melting point is lower than water?

My teacher told us that melting point of Iodine is lower than Ice as it is a Simple molecular structure bonded by weak van der waals forces. However I gooogle and found out its melting point is 113.7°...
0
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1answer
4k views

Intermolecular Forces for Ionic Compound?

So in class we have learned London dispersion, dipole-dipole, ion-dipole and hydrogen bonding for intermolecular forces. Our teacher always uses covalent molecules as examples. So I was wondering ...
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2answers
53 views

What other intermoelcular forces can exist between neutral molecules?

I've been doing some basic chemistry exercises (about intermolecular forces), and there are two I failed and don't quite understand: What kind of intermolecular forces can exist between neutral ...
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1answer
59 views

Why do self-replicating molecules dissociate?

I am new to chemistry (have only done a GCSE) so I apologize for my lack of knowledge. But I am confused about why self-replicating molecules dissociate. It is my understanding that a self-...
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2answers
1k views

Sublimation of Iodine

Why does iodine sublime? I have researched it myself and I have got the same answer; it sublimes because it directly converts from solid to gas. But why don't bromine or chlorine also sublime?