Questions tagged [polarity]

For questions about polar or non-polar chemical species, or their comparison. Also, for questions where polar or non-polar solvents have an effect.

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Why is carbon dioxide nonpolar?

I understand that polarity corresponds to an electronegativity difference and that the larger the electronegativity difference, the more polar the bond. However, I have read that carbon dioxide is ...
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Non-zero dipole moment of hydroquinone

Why does hydroquinone possess a non-zero dipole moment? The $\ce{OH}$ groups present at para positions on the benzene ring should cancel the effect of each other... if there is a plane change then ...
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Why are bonds ionic when the electronegativity difference between bonded atoms is greater than 1.7?

I'm learning about how to recognise whether a bond is ionic or covalent, based on the difference in electronegativity between the two bonding partners, $\Delta \chi$. What I have now is a formula: ...
LeDuc's user avatar
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17 votes
3 answers
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Is the triiodide ion polar?

Three professors argue it is non-polar. My professor argues that it is a monopole, like most ions. The structure of the triiodide ion places a negative formal charge on the central iodine atom. The ...
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Why is water a dipole?

Water ($\ce{H2O}$) is a dipole. The reason why is simply because it is not symmetrical, there are more electrons on the oxygen side than on the hydrogen side, and the electronegativity of oxygen. But ...
Friend of Kim's user avatar
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2 answers
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Difference of dipole moments of dichloromethane and trichloromethane?

Why is the dipole moment of $\ce{CH2Cl2}$ ($1.60 ~\mathrm{D}$) greater than that of $\ce{CHCl3}$ ($1.08~\mathrm{D}$)? Based on my knowledge of vectors, I feel it should be the other way around.
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Does resonance affect the polarity of the molecule?

Ozone is a resonating structure, is it because of its resonance and bent structure that it is a polar molecule? Or Is it because of the formal charges whereby the formal charges determine the ...
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Quadrupole moment of a molecule

What is a quadrupole moment of a molecule and how does it arise? How is it measured for a particular molecule? I've read the Wikipedia article on quadrupoles and understand that it has to do with the ...
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In practice, do polar molecules actually align in an electric field?

We have all seen the following diagram (or similar) in our first chemistry class, depicting polar molecules aligned in an electric field. Is this just one of the half-truths of beginner chemistry or ...
ericnutsch's user avatar
10 votes
1 answer
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Why does ozone have an electrostatic potential map similar to that of SO2?

This is the electrostatic potential for ozone. This is the electrostatic potential for sulfur dioxide. (Click to enlarge) They look almost exactly the same except one is all oxygen atoms and the ...
Caters's user avatar
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What is the explanation of the changes in stability going down a group for carbonates, bicarbonates, fluorides, and chlorides?

For carbonates and bicarbonates, I know that stability increases down the group, and for chlorides and fluorides, stability decreases down the group. Why does this happen? Can someone explain this in ...
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What is the order of the following compounds based on polarity?

What is the order of the following compounds from more polar to less polar? Hydrochloric acid, Methanol, Hexane, Petroleum benzene I know that $\ce{HCl}$ has the largest ...
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What determines "polarizability" of an element?

In this question, the answer given discusses that fluorine has a good orbital overlap with hydrogen and also that fluorine is not very polarizable. However, is it always true that strong bonding is ...
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28 votes
5 answers
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Why is water "the universal" solvent?

This is an old question that our textbook tried to answer but worsened the situation. Many things are soluble in water. So many, that studying solutions will always require studying aqueous ones. It ...
M.A.R.'s user avatar
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18 votes
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Dipole moment of cis-2-butene

I need someone to back me up on this before I go confront my teacher: I was doing some analysis of the dipole moment of cis-2-butene. Let's say that the alkyl groups are both on top. Would the dipole ...
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Why are some molecules unable to absorb infrared radiation?

Methane $\ce{CH4}$ is symmetrical and non polar, and so is oxygen $\ce{O2}$. But $\ce{O2}$ doesn't absorb IR. Why is that? People say that if a molecule can change its polarity then it will absorb IR, ...
user41793's user avatar
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Why don't polar and non-polar compounds dissolve each other?

Dipoles can also be induced in polar and non polar compounds, then why don't they dissolve?
Hammad Ahmed's user avatar
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Difference between polarity and polarizability

How do the terms polarity and polarizability differ from each other? In my opinion, polarity is the degree of ionic character in covalent compounds and polarizability implies towards degree of ...
Rajarao K's user avatar
3 votes
2 answers
18k views

Why is fat nonpolar?

Why is fat nonpolar while water is polar? In water there is the $\ce{H-O}$ bond and the $\ce{O}$ is more negative, we have $\text{dipole = charge}* \text{distance}$ A fat molecule is like $\ce{H-O-C-...
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Is there a difference between dipole and dipole moment?

I’m confused as to whether both terms “dipole” and “dipole moment” are the same or different, does the moment have something to do with the molecular geometry? I know the vectors of the charges cancel ...
user79943's user avatar
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4 answers
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Easiest way (software) to visualize charge density from an .xyz file with point-charges?

I have an .xyz file which contains partial charges calculated by a Quantum-Chemistry software (NWChem). The system looks like this, here I show the partial charges calculated from the electrostatic ...
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What is the exact reason that compounds such as carbon dioxide cannot interact with other compounds through dipole-dipole interactions?

Whilst I understand that $\ce{CO2}$ has a linear structure, resulting in a vector sum of the dipoles of 0, I do not understand why the dipoles formed at the two oxygen atoms as a result of their ...
Vihanga Dharmasena's user avatar
7 votes
4 answers
40k views

Why is tetrafluoromethane non-polar and fluoroform polar?

Consider the Lewis dot structures of the molecules fluoroform, $\ce{CHF3}$, and tetrafluoromethane, $\ce{CF4}$:   My first line of thought is that both of these molecules are symmetrical (the ...
Luis Averhoff's user avatar
5 votes
2 answers
10k views

Polarity index vs. Dipole moment

I'm looking to find whether water or methanol is more polar, and I'm getting conflicting answers. My textbook says "the polarity of a bond is quantified by the size of its dipole moment." According ...
user3932000's user avatar
5 votes
2 answers
78k 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.
azaidi's user avatar
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How to determine polarity in large molecules?

In case of small molecules like water things are more or less clear, but when I see a large complex molecule like Thyroid Hormone - how should I find out that this molecule is non-polar?
Stanislav Bashkyrtsev's user avatar
4 votes
1 answer
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Why is sand/glass polar? How does lattice structure change polarity?

The molecular geometry of sand is linear. Dipole moment is thus cancelled. But we all know from the meniscus water makes with glass that the dipole-dipole/H-O attraction between sand and water is ...
user134789's user avatar
3 votes
1 answer
2k views

Why does the C-C bond break earlier than the C-F bond in the pyrolysis of perfluroethane?

According to me $\ce{C-F}$ bond is highly polar and thus is a weaker bond as compared to $\ce{C-C}$. Hence, $\ce{C-F}$ should break first in the pyrolysis of perfluroethane. Instead, in J. D. Lee, it ...
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Are elemental compounds composed of different isotopes polarised?

Are elemental compounds composed of different isotopes polarised? I'd expect any such effect would only really be noticeable for very light elements such as hydrogen. I'm not sure which way the ...
Molly Stewart-Gallus's user avatar
3 votes
0 answers
154 views

Supercritical fluids polarity

Water is a polar solvent, but in the supercritical fluid state, it is much less polar, I presume because of the cleavage of hydrogen bonds. On the other hand, carbon dioxide is non-polar, but as a ...
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Why is a cationic trialkylammonium functional group inductively withdrawing in nature?

The alkyl groups on the nitrogen ion should donate electrons (alkyl groups are electron donating in nature). So, irrespective of the nitrogen ion being a cation (which is an electrophile), the alkyl ...
Ishaan's user avatar
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3 votes
1 answer
2k views

Why distinguish between polarity and hydrophobicity?

I have yet to see an example of a molecule that's both polar and hydrophobic or that's both non-polar an hydrophilic. If no such molecule exists, why use the terms "hydrophilic" and "hydrophobic" at ...
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1 answer
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Comparing Polarity of Amino Acids

I know that there are polar uncharged amino acids (serine, threonine, asparagine, glutamine, cysteine) and polar charged amino acids (the basic and acidic amino acids). Does the charge on the acidic ...
Mel's user avatar
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3 votes
1 answer
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Relationship between dipole moment of a molecule and electronegativities of constituent atoms

I want to know if I can calculate the dipole moment of a molecule given the electronegativity values for the atoms comprising it. I think that dipole moments determine the polarity of molecules, so ...
phi2k's user avatar
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2 votes
2 answers
695 views

How does one apply the knowledge of the direction of a molecular dipole moment?

I was watching Khan academy's video about molecular dipole moments, which explained what they are and how they can be calculated. I also read this article. Both sources explain the concept similar ...
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2 votes
2 answers
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Why is H2S more polar than HCl?

From EN alone we might expect $\ce{HCl}$ to be more polar but a book says that the bent structure of $\ce{H2S}$ gives rise to its polarity - which is also apparently more than $\ce{HCl}$. Why? Does ...
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1 vote
1 answer
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Why is the C-Br bond considered polar?

Why is a C-Br bond considered polar? From electronegativity considerations, both carbon and bromine have very similar electronegativities - 2.5 and 2.8 - respectively. Nonetheless, I am told that ...
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1 vote
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Which isomers (cis or trans) are more water soluble?

As a general sense I know that cis isomers are less symmetrical and more polar in nature whereas trans isomers are less polar. Now given those information, would it be appropriate to assume that cis ...
Aniruddha GS's user avatar
1 vote
1 answer
13k views

Dichloromethane solubility in water

I heard dichloromethane is soluble in water 1:50, but I also heard it is not because it can't form hydrogen bonds. I'm confused. Is there a way to extract it? Would putting the water to $40~\mathrm{^\...
simon's user avatar
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1 answer
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Why H2O2's molecular geometry is what it is...? [duplicate]

I came up with this question when I was trying to determine whether H2O2 is polar or not. H2O2 looks like this when looked parallel to oxygen-oxygen bound:(source: Pubchem) Each hydrogen is in one ...
Amir Moeini's user avatar