Questions tagged [electronegativity]

Refers to ability for an atom in a covalent framework to attract electron density to itself. Do not conflate with electron affinity, which is the ability of a lone atom (or molecule) to attract an electron to itself. Both are measured in joules/mole.

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1answer
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Why does attractive forces of nucleus increase more than shielding across groups?

When you study the electronegativity of the elements, the general trend is that it rises with increasing group number, and decreasing period. Supposedly this is because the attractive forces of the ...
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Electron distribution in a C-S bond

My lecturer said that in a $\ce{C-S}$ bond, sulfur is slightly $\delta^{-}$ and the carbon slightly $\delta^{+}$, although they have (almost) the same electronegativity. What is the cause of this ...
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Why is HCl not considered to have hydrogen bonding?

A molecule that has hydrogen bonding usually follows these two premises. 1.) There is a hydrogen atom involved 2.) Hydrogen must be bonded to a highly electronegative element which are ...
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What should be the oxidation state of oxygen in HOF (hypofluorous acid)?

What should be the oxidation state of oxygen in $\ce{HOF}$ (hypofluorous acid)? Sources on the internet have confused me. Most state its oxidation state to be 0, while the others state that it is -2 (...
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Electronegativity Considerations in Assigning Oxidation States

I have never seen anything other than a set of rules like these when textbooks present how to assign oxidation numbers. Such as these: However, if we keep in mind that oxidation numbers are simply ...
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1answer
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Why must polar molecules be asymetrical? [duplicate]

As I understand, polarity in molecules comes from the difference in electronegativity or the ability of the atoms to attract eletrons so the electrons spend more time or are more probable to gravitate ...
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Relationship between electronegativity and atomic radius [closed]

Would someone please explain in detail the relationship between the two? I understand that atomic radius is related to ionisation energy but I can't see how atomic radius may be related to ...
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Reference for electronegativities of different metal oxidation states

A long time ago I was researching the effect of the self regulatory response in Fe and Co. I found that my results made sense based on the idea of the electronegativity of the ions considered. I found ...
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How to determine polarity of components in TLC

Estimate how a TLC-analysis would look like for the following reaction when you take a TLC at: a) the start of the reaction, b) after 65% conversion and c) after full conversion of A. (You may assume ...
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How is Al2Cl6 covalent and Al2O3 ionic?

I encountered a question where the type of bonding for various oxides are prompted. Two of which are $\ce{Al2Cl6}$ and $\ce{Al2O3}$. I thought that chlorine atoms are more electronegative than oxygen ...
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Why is HF the least acidic hydrogen halide?

Fluorine is the most electronegative halogen and therefore, there is larger difference in electronegativity between the atoms of $\ce{HF}$ than any other hydrogen halide, which means the positive ...
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Why do Hydrogen Halides(with the exception of HF) form mostly strong acids? [duplicate]

Why do Hydrogen Halides(with the exception of HF) form mostly strong acids? My guess is that the negatively charged Halide part of the molecule is attracted by the partially positive part of the water ...
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Confusion between electronegativity and electron affinity

Electronegativity is a chemical property that says how well an atom can attract electrons towards itself. The electron affinity of an atom or molecule is defined as the amount of energy released ...
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Comparing Acidic Strength of H3PO4 and H3AsO4

The $pKa$ values for H3AsO4 and H3PO4 are $2.30$ and $2.12$ which indicate that H3PO4 is a stronger acid compared to H3AsO4. I looked up their electronegativity values to find that they are almost the ...
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Confusions about inductive effect and acid strength

If one of the hydrogens in the alkyl side chain of ethanoic acid is replaced with an atom of Chlorine, the acid has a larger Ka value. My book says this is since the Cl "borrows" electron density from ...
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What is the correlation between electronegativity and the sharing of electrons?

For example in a C-O bond, the electronegativity difference is 1.2. does this mean that the Oxygen has 1.2 of the shared electrons and Carbon 0.8 (or some other numbers)? Is there a specific equation ...
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Can an element have variable oxidation states in a compound?

Take propanoic acid for example. If I assign oxidation states to the 3 carbons in it using the idea that the more electronegative element gets all the electrons in the bonds it makes, the 3 carbons ...
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Why does electronegativity create a stronger acid, but so does greater electron distribution?

I just learned that: Acids get stronger with: Increasing electronegativity of atom bonded to $\ce{H}$. Size of atom bearing negative charge. Hybridization of negative charge (more s character, $\ce{...
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Difference between electropositivity and electronegativity

Sodium is more electropositive than hydrogen although they are in the same group. Why is the electronegative value of hydrogen greater than sodium (metal)?
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Why is the electronegativity of indium greater than that of thallium?

Why is the electronegativity of indium greater than that of thallium? One possibility which I had assumed was the poor shielding effect by the d and f orbitals which leads to an increase in the ...
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Does a C=C double bond donate electron or withdraw it?

I have learned that a $\ce{C=C}$ double bond is electron-rich because of the p-p overlap and hence can easily donate an electron pair: I agree with this statement. However, in a $\ce{C=C}$ double ...
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1answer
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Relationship between effective nuclear load and periodic properties

The effective nuclear charge is defined as the net positive charge experienced by an electron in a polyelectronic atom. It can be calculated using the well-known Stars Rule. Once I have calculated ...
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Which Oxygen atom in HCOOH (formic/methanoic acid) does Carbon donate its electrons to, to obtain a partial positive charge?

I was wondering if the Carbon atom in HCOOH (methanoic/formic acid) forms a positive partial charge by donating its electrons to both the Oxygen atoms, since they both possess a higher ...
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electronegativity and how it relates to bond strength

my question is, if the strength of the bond between two atoms increases as the difference in electronegativity increases as well. so say, a H-F bond would be stronger than a O-H bond. I'm a little ...
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Strongest negative inductive effect group between trimethylammonium, ammonium and dimethylsulfonium groups

Which of the following group exerts the strongest -I effect? $\ce{-N(CH3)3+}$ $\ce{-NH3+}$ $\ce{-S(CH3)2+}$ $\ce{-F}$ My idea is that positive species exerts more -I effect than ...
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Why is carbon monoxide a monodentate ligand

Carbon monoxide has lone pairs on both the carbon and the oxygen atoms. However, I have never seen any complex where the oxygen atom or both the oxygen and the carbon atoms are the donors. I know ...
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Percentage ionic character when electronegativity is given

What is the ionic character of a bond, $\ce{A-B}$, in terms of the electronegativities of $\ce{A}$ and $\ce{B}$ ($\chi_\ce{A}$ and $\chi_\ce{B}$)? I have been taught that the percentage ionic ...
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Why are noble metals more electronegative then most metals?

I was researching about electronegativity when I looked up what a graph of electronegativity within the periodic table is. And, this appeared. I scanned it, matching up everything I knew about the ...
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Where will a H+ attack on 6-hydroxyhexan-2-one? [closed]

Where will a H+ attack on 6-hydroxyhexan-2-one? Protonation can take place either on the ketone or the alcohol. So where will it attack? In short, on which of the two oxygen atoms is electron density ...
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Why is hydrogen not very electronegative? [closed]

I looked at my reactivity series and I have just realized that hydrogen and carbon are both included in the series, even though they are non-metals. So why is hydrogen more electropositive than ...
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Why is fluorine one of the most electronegative atoms even though it doesn't have the largest effective nuclear charge?

Why doesn't electronegativity increase as the effective nuclear charge increases? Most atoms with a higher atomic number than fluorine have a higher effective nuclear charge. However, flourine is a ...
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Is the inductive effect always measured relative to hydrogen?

Wikipedia has defined the Inductive effect thus: "In Chemistry and Physics, the inductive effect is an experimentally observable effect of the transmission of charge through a chain of atoms in a ...
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Calculating the electronegativity of an element from bond dissociation energies

Calculate the electronegativity of fluorine from the following data: $$\begin{align} \text{BDE}(\ce{H-H}) &= \pu{104.2 kcal/mol} \\ \text{BDE}(\ce{F-F}) &= \pu{36.6 kcal/mol} \\ \text{...
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Structures for NO+ (Nitrosonium)

There are two possible structures for Nitrosonium : In the first structure, there is a +1 Formal charge on Oxygen, whereas, In the second structure, there is a +1 Formal charge on Nitrogen. Q. ...
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Is there a mathematical formula for electronegativity?

If we lost all the numerical values we have for the electronegativity of elements, is there any mathematical formula that can be used to re-calculate them based on proton (and neutron) numbers alone? ...
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Relative strengths of hydrogen bonds

Order of hydrogen bond strength: $\ce{O-H...N}$ > $\ce{O-H...O}$ > $\ce{N-H...N}$ > $\ce{N-H...O}$. Why is that so? According to me $\ce{O-H...O}$ should have the maximum strength while $\...
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Geometries of SCl2(OCH3)2 and SF2(OCH3)2

I am not able to understand the difference between structure of $\ce{SCl_{2}(OCH_{3})_{2}}$ and $\ce{SF_{2}(OCH_{3})_{2}}$. I am already well versed with Molecular Orbital and VSEPR theories. I found ...
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why fluorine and oxygen have different behaviour towards electron gain enthalapy and electronegativity? [closed]

I have seen following definitions in my textbook: Electron gain enthalapy may be defined as enthalpy change taking place when an isolated gaseous atom of the element accepts an electron to form a ...
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Why is zinc more reactive than copper?

In terms of electronegativity, from what I understand electronegativity increases going across the period, so surely this should mean that zinc less readily loses its outer shell electrons than copper?...
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Why is the bond dissociation energy of C-H bond higher than that of a N-H bond?

Looking at a chart of BDEs (bond dissociation energies) regarding elements bonded with hydrogen, the general trend seems to be that the BDE increases as we go to the top and to the right. This can be ...
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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 ...
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Using electronegativity and atomic size to compare acidity of cysteine with serine

In proteins, the alcohol group of serine is generally more difficult to deprotonate than the thiol group of cysteine. Serine and cysteine respectively: In the literature, the explanation given is ...
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Effect of Electronegativity on Bond Angles in NH3 and NF3 [duplicate]

I am reading a book: Concise Inorganic Chemistry by J.D.Lee (Fifth Edition) In the chapter-The Covalent Bond, the author says: $\ce{NF3}$ and $\ce{NH3}$ both have structures based on a tetrahedron ...
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How does an atom's electronegativity change as it becomes more negatively charged?

I had a question about the carbon atom specifically. Carbon has 4 valence electrons, with electronegativity 2.55 (approx). If I was to fire electrons at the carbon atom, each carbon will occupy up to ...
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Why do atoms have electron Affinity? [duplicate]

Atoms are stable so how can they pull electrons i.e how do they have any electron affinity at all?
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Will there be change in electronegativity difference in C-O and C=O?

Is there any change in EN difference in C-O and C=O. If yes, why? Does EN difference change if its bond is changed to single, double, or triple?
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Why does C=O have a larger dipole moment than C-O?

Why does $\ce{C=O}$ have a larger dipole moment than $\ce{C-O}$? According to me, dipole moment directly depends upon bond length and electronegativity difference. In $\ce{C=O}$ and $\ce{C-O}$, (I ...
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1answer
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What measures of the dielectric constant mark whether the solution is ionic, polar and nonpolar? [closed]

At what numerical values of ε, then what organic compounds if any mark these thresholds. How is that only for a vacuum has ε=1? This is absolute lowest limit?
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Allred-Rochow vs Pauling Electronegativity scale

While observing the trends in electronegativity of the elements, I found a discrepancy between Allred-Rochow and Pauling scales. In Pauling's scale, chlorine is the third most electronegative element (...
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2answers
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How can I relate the reactivity series to electronegativity and ionization energy?

I am trying to figure out how the reactivity series comes about. My understanding is that elements with a higher electronegativity will be more reactive than elements with a lower electronegativity, ...