Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [vsepr-theory]

For questions about the valence shell electron pair repulsion (VSEPR) theory, in topics of: estimation of bond length, bond angle, bond energy, etc.; determining hybridization of atoms, or shape and geometry of molecules; and other related topics.

-1
votes
1answer
24 views

Why lone pair in XeF4 is in axial position? based on VSEPR [on hold]

According to VSEPR lone pair is best adjusted in the equatorial position but in XeF4 it is in axial. Can anyone please explain in detail?
1
vote
0answers
29 views

Dichlorine monoxide molecular geometry

I need to predict the geometry of Dichlorine monoxide, using the main link theory: Lewis model, VSEPR and hybridization of molecular orbitals. First, the Lewis structure is a graphical representation ...
-1
votes
1answer
43 views

Molecular geometry of acetylene

I need to determine the molecular geometry of acetylene, for this I have performed the following procedure: First, we represent the correct Lewis structure. Remember that the Lewis structure is a ...
0
votes
0answers
39 views

A question on VSEPR theory

My book explained why the electrons in the $[\text{XeF}_{5}]^{-1}$ are at the axial positions by stating that: It appears contradictory that the two lone pairs are at the axial positions in $[\text{...
1
vote
1answer
30 views

Do all sigma bonds are stronger than pi bonds? [closed]

Many textbooks refer that sigma bonds are stronger than pi bonds . But each individual bond ( between different atoms) have different bond energy. So how we know for sure that every possible sigma ...
4
votes
1answer
118 views

Shape of urea molecule around N atom

I was doing a question where I was supposed to predict the shape of the urea molecule $[\ce{H2N(CO)NH2}]$ using Lewis and VSEPR. I identified that the N atoms will have a lone pair on them and so I ...
0
votes
1answer
49 views

POI is a bent molecule similar to water. How are the two molecules different it terms of bond angles and what causes this?

phosphorus oxyiodide ($\ce{POI}$) has the VSPER AXE formula of $\ce{AX2E}$ while water, $\ce{H2O}$ has the AXE code of $\ce{AX2E2}$. According to my work sheet $\ce{POI}$ should have a $120^\circ$ ...
0
votes
0answers
34 views

VSEPR Theory confusion for me [duplicate]

Can you please explain what is given here Why do lone pairs occupy more space. Even if they did shouldn't the repulsion between them be less because they occupy more space and placed more farther ...
5
votes
1answer
74 views

Is there an algorithm that takes atom coordinates and produces VSEPR geometries?

That is, you would give the coordinates of an atom, the coordinates of four (for example) other atoms, and it would return "tetrahedral" or "square planar" or whatever. I'm currently writing a ...
0
votes
0answers
226 views

Bond Angle in Diborane, B2H6

Why are the bond angles in the diborane $\ce{B2H6}$ ring much less than $\ce{109.5^o}$? Below is the structure: This source says that the boron atoms are approximately $\ce{sp^3}$ hybridized, so I ...
1
vote
1answer
1k views

Lone pair on carbon in CO2? [closed]

CO2 has sp hybridization and no lone pairs on carbon. For some reason calculation with VSEPR gave sp2 hybridization and lone pair on carbon.
-1
votes
3answers
902 views

Bond angle in CH3NCO

I was doing past year papers of A levels Chemistry, when I came across this problem: I answered (A), but the correct answer is (C) according to the marking scheme. I thought it was a bent-shaped, ...
2
votes
2answers
234 views

VSEPR bond angles [duplicate]

My teacher gave a practice exam concerning VSEPR and bond angles and in the following diagram, he wrote the bond angle as greater than 109.5. However, I thought that the ideal angle should be 109.5 ...
6
votes
2answers
1k views

Determine the geometry of each nitrogen atom in formamidinium ion

The geometry at A seems to be straightforward: $\ce{N}$ is surrounded by $\ce{C}$ and two $\ce{H}$'s. By VSEPR, this is trigonal planar. For the geometry at B: $\ce{N}$ is surrounded by $\ce{C}$, two ...
4
votes
0answers
156 views

What's the hybridization in diphosphorus molecule?

I read that diphosphorus has 2 phosphorus atoms joined by a triple bond (ie) it has one sigma bond and 2 pi bonds with 2 lone pairs ( 1 lone pair on each atom). I'm confused about the hybridization of ...
4
votes
1answer
394 views

VSEPR theory, chemical bond and quantum mechanics

VSEPR theory correctly predicts the shapes of many symmetry-broken molecules such as $\ce{H2O}$ and $\ce{NH3}$. Take $\ce{NH3}$ for example. In VSEPR theory, the nitrogen atom is (approximately) at ...
2
votes
1answer
488 views

Draw a diagram to show the shape of Chloromethane and explain why it has this shape. [closed]

I know it has this shape, but I don't know how to explain it. Any help is appreciated, thanks.
0
votes
0answers
119 views

How many lone pairs are there in a molecule, if it has 5 electrons (unbonded) in the valence shell?

While learning the vsepr theory, I myself thought of a random compound ClF2.(I don't know if it exists). Now I know how to arrange the valence electrons in the equitorial position and all but I got a ...
2
votes
0answers
90 views

How does the phosphate ion look like? [duplicate]

I am trying to understand how a phosphate ion looks like using the VSEPR theory. The phosphorus element has an atomic number of 15, and therefore it has a electron configuration as follow by the ...
8
votes
1answer
2k views

What is a stereochemically active or inactive s orbital?

In Concise Inorganic Chemistry by JD Lee (4th edition; adapted by Sudarshan Guha), page 73 under the section 3.6 (VSEPR Theory chapter Chemical Bonding): ...according to this theory, the position ...
0
votes
1answer
2k views

VSEPR theory and hybridization in determining the shape of a molecule

Our chemistry teacher told us that both VSEPR theory (which says that the electron pairs in the valence shell of an atom arrange themselves in such a way that repulsions among them are minimized and ...
2
votes
1answer
248 views

What is the Si–N–C bond angle in silyl isothiocyanate?

In silyl isothiocyanate, supposedly, the value of the bond angle $x$ is $180^\circ$. I don't know how to figure this out. There is a lone pair on nitrogen and two sigma bonds. Shouldn't it have sp2- ...
3
votes
1answer
2k views

Valence Bond theory, VSEPR theory and predicting the shapes of the molecules

I read about the above mentioned theories then used them to predict the molecular geometry. However, I found that the shape/geometry of a molecule obtained from both the theories was same. For example,...
0
votes
1answer
2k views

Why lone pair occupies more space than bond pair? [duplicate]

I'm not a chemistry expert and merely a high school student. In my book there is a slight introduction to VSEPR theory and therein they mention that lone pair-lone pair repulsions are maximum, ...
11
votes
2answers
5k views

Are carbocations necessarily sp2 hybridized and trigonal planar?

My copy of Pearson's Organic Chemistry (7e), Morrison and Boyd, under the section "Reaction intermediates", accords a succinct description on the structure of carbocations: The central $C$-atom (of ...
7
votes
1answer
589 views

How to explain molecular geometry without the help of VSEPR, valence bond, or hybridization theories?

I was taught, at the high school level, how to rationalise molecular geometries with the help of VSEPR, valence bond, and hybridization theories. However, I have recently also come to know that these ...
1
vote
1answer
985 views

Polarity of xenon fluoride

The structure of xenon fluoride is a capped octahedron. The lone pair is stereochemically active, i.e. it will rotate about. The dipole moments of the axial fluorides will get cancelled, and so will ...
-1
votes
1answer
2k views

VSEPR Theory and Predicting Shapes of N2F2

I had asked a question on a IA Past Paper. The question was: "Predict the structure of $\ce{N2F2}$ using VSEPR Theory." Now I'm not that strong at VSEPR theory. For the most part, I understand it ...
5
votes
0answers
482 views

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 ...
5
votes
2answers
2k views

What is the molecular shape of Sulfur Pentafluoride Anion?

$\ce{SF6}$ is an octahedral shape which makes perfect sense. $\ce{SF5^+}$ arranges 5 pairs of electrons in a trigonal bipyramidal structure. But what if you add a lone pair to this? Will the electron ...
-1
votes
1answer
676 views

Why doesn't fluoride ion have highest nucleophilic power (nucleophilicity)?

As you can see from the image above, '$\ce{R3C}$' anion has 1 lone pair '$\ce{R2N}$' anion has 2 lone pairs $\ce{RO}$ anion has 3 lone pairs $\ce{F}$ anion has 4 lone pairs According to VSEPR theory,...
1
vote
0answers
101 views

Cl-A-Cl bond angle discrepancy

In 2,2-dichloropropane the Cl–C–Cl angle (108.3°) is less than the C–C–C angle (113.0°). In Me$_2$TiCl$_2$, in contrast, the Cl–Ti–Cl angle (116.7°) is larger than the C–Ti–C angle (106.2°). How is ...
1
vote
1answer
142 views

Why is the molecular geometry of a molecule with 5 bonds not uniform? [duplicate]

I'll note that I'm a student in a rather introductory course, and today we learned about molecular geometries. I'm curious as to why certain geometries (say, $\ce{CH4}$, tetrahedral) are uniform (...
2
votes
1answer
604 views

Is orbital hybridisation real?

Is the concept of orbital hybridisation an accurate description of a physical process that actually occurs in bonding atoms, or is it, like VSEPR, a heuristic tool to reason about the characteristics ...
0
votes
1answer
560 views

Is the VSEPR theory correct in determining the bond angle of sulfur dioxide?

Recently when we were doing the VSEPR Theory in class and discussing the bond angles in various compounds. That's when I thought of sulfur dioxide whose structure can be like this: According to the ...
1
vote
3answers
3k views
4
votes
4answers
7k views

Why does NF3 have a smaller bond angle than NH3?

I've already read many answers about the reason why $\ce{NF3}$ has a smaller bond angle than $\ce{NH3}$ , but I can't seem to understand them. Here's my understanding of the situation: $\ce{NH3}$: ...
0
votes
2answers
317 views

How can I derive whether the methyl cation or anion is planar?

According to VSEPR theory, in which species do all the atoms lie in the same plane? $\ce{CH3+}$ $\ce{CH3-}$ (A) 1 only (B) 2 only (C) both 1 and 2 (D) neither 1 nor 2 My try: ...
8
votes
2answers
4k views

Why is the H-C-H bond angle in CH3Cl larger than 109.5?

Symmetrical tetrahedral molecules (like $\ce{CH4}$) have a bond angle of $109.5$. Those with lone pairs in place of one atom (like $\ce{NH3}$) have bond angles less than $109.5$. The standard ...
0
votes
1answer
878 views

If a molecule has both polar and ionic bonds in it, is it polar or nonpolar overall?

To be more specific, lets take a look at the Lewis Structure of two such examples: The first one is SiCl${_3}$F. The red arrow represents an ionic bond while the blue is a polar covalent bond. ...
6
votes
1answer
2k views

Bond angles of OCl2 and OBr2

I have looked around and most of the sites suggest that bond angle of $\ce{OBr2}$ is greater than $\ce{OCl2}$ and it is explained by stating the electronegativity difference and looking at electron ...
-2
votes
2answers
33k views

How do I identify Lone pair and bond pairs in molecules?

How do I identify the lone and bonding pairs in $\ce{BeCl2}$?
-1
votes
1answer
116 views

Help regarding stereochemically inactive s orbital [duplicate]

Author JD Lee says in his book, Inorganic Chemistry The dipole moment of $\ce{XeF6}$ is approximately = $0$ because the lone pair is present in the stereochemically inactive s orbital. What is ...
0
votes
0answers
37 views

where will be highly electronegetive atom placed? [duplicate]

consider a molecule PCl3F2 here F is more electronegetive than Cl, which of them should occupy axial position??when i searched on internet i found these two images , they increased my confusion ...
1
vote
1answer
6k views

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 ...
5
votes
0answers
49 views

Why do some molecules form T shapes instead of trigonal planar shapes [duplicate]

Consider a molecule such as $\ce{ClF_3}$. Shouldn't the electron clouds (which are more negative than the Chlorine atom) want to repel each other and so the $\ce{ClF_3}$molecule should arrange into a ...
38
votes
2answers
3k views

Are the lone pairs in water equivalent?

I've read that the oxygen atom in water is $\mathrm{sp^2}$ hybridized, such that one of the oxygen lone pairs should be in an $\mathrm{sp^2}$ orbital and the other should be in a pure p atomic orbital....
0
votes
1answer
194 views

Are there any strategies to determine bond order and hybridization rankings without drawing the Lewis Structure?

I'm not Chemist. I'm taking a chemistry class in college, and the test review contains many questions where I'm asked to rank from least to greatest based on bond order, polarity, and bond angles. I ...
3
votes
2answers
7k views

What is hybridisation of XeF6 in solid state?

According to the following formula: Type of hybridisation/steric no. = (no. of sigma bonds + no. of lone pairs) it should be $\ce{sp^3d^3}$, however according to my textbook it is $\ce{sp^3d^2}$ in ...
9
votes
1answer
3k views

Why are the two CH2 groups in allene perpendicular to each other?

Allene, $\ce{H2C=C=CH2}$, has two $\ce{=CH2}$ groups perpendicular to each other. This is the same as hydrogen peroxide's $\ce{H}$ atoms. Is there any reason why they adopt the perpendicular ...