Tagged Questions

Valence shell electron-pair repulsion (VSEPR) theory provides simple explanations for the general shapes of molecules based on repulsion of bonding pair and lone pair electron repulsions, and we developed by Sidgwick and Powell and later Gillespie and Nyholm.

learn more… | top users | synonyms

2
votes
0answers
28 views

How is the thermal stability of nitric acid related to its structure?

How is the thermal stability of nitric acid related to its planar structure? In textbooks it is written that nitric acid is unstable at room temperature and decomposes where $\ce{H2SO4}$ and ...
4
votes
1answer
67 views

Asymmetry in trigonal bipyramidal geometry

I teach an MCAT course in chemistry. I like to explain VSEPR by saying.. first, imagine arranging electron pairs around the central atom so they are maximally distant from each other, and uniformly ...
7
votes
1answer
108 views

Why is disilyne bent?

Why is disilyne $\ce{Si2H2}$ bent when the steric number of silicon is 2?
0
votes
1answer
137 views

If you try to use the VSEPR model to predict the molecular geometry of XeF6, you run into a problem. What is it?

A. If you try to use the VSEPR model to predict the molecular geometry of XeF6, you run into a problem. What is it? B. What could you do to resolve the difficulty in part A? C. The molecule IF7 has a ...
5
votes
3answers
173 views

Lone Pair 'more repulsion' VSPR Theory

I've always been told in chemistry lessons that lone pairs repel more due to a greater charge density than bonding pairs. And that makes sense when steric effects are involved when bond orbitals ...
2
votes
1answer
27 views

Quantum Valence Theory Reference

At least to me, the contents of chapters 5 & 6 given here are representative of discussions on chemical bonding given in nearly all intro general & organic chem books, the statements in those ...
8
votes
1answer
141 views

Does the hybridization model gives us any further insight on Molecular Geometry?

It doesn't seem as though the hybridization model adds anything useful to the discussion of molecular geometry as predicted by the VSEPR model. It's just another way of labeling linear, trigonal ...
2
votes
1answer
104 views

Finding the number of orbitals on a central atom

In $\ce{BeCl2}$ the number of orbitals on central atom, i.e. on beryllium, are 2. In $\ce{BF3}$, the number of orbitals on central atom , i.e. on boron, are 3. Similarly in $\ce{NH3}$ there are 4, ...
0
votes
2answers
665 views

Predicting electronic geometry, observable geometry, and hybridization for any atom in a molecule

Can someone please explain the intuition around the answers to this problem: I'm finding it very confusing because it seems like you have to nitpick between two resonance structures to get the ...
5
votes
4answers
627 views

Why are sigma bonds the only ones used in determining the geometry and bond angle in VSEPR theory? Why aren't Pi bonds used?

I have read that in VSEPR theory, multiple bonds are considered or treated as single bonds when predicting the geometry of a molecule? I've read in yahoo answers that it is because only sigma bonds ...
5
votes
0answers
99 views

Molecular Imaging - Any surprises to be had?

Molecular imaging, using STM and AFM technologies, appear so far to visually prove most of what we already know about chemical structures, such as VSEPR theory. For instance, here are the ideal ...
2
votes
1answer
114 views

Tetrahedron is minimum energy conformation for atom with 4 electron domains in VSEPR theory

Background A student asked me to prove that the regular tetrahedron is the minimum energy geometry available to describe the locations of the electron domains in three dimensions – the prediction of ...
2
votes
1answer
268 views

Bent molecular geometry of water

Could you please explain how the bent molecular geometry of water is due to hydrogen bonding? I was under the impression that it was because of the lone pairs (VSEPR Theory).
6
votes
1answer
1k views

Why do single, double and triple bonds repel each other equal amounts?

I'm here to share with you something that totally confuses me, as I can't see the logic behind it, and my teacher doesn't know either. Let's take a set of bonds that's trigonal pyramidal, with a lone ...
3
votes
1answer
127 views

Shape of C₂H₂ molecule

What is the shape of the $C_2H_2$ molecule? The fact that is has a triple covalent bond between the 2 carbon atoms and 2 other bonding pairs between the hydrogen and carbon atoms leads me to believe ...
9
votes
5answers
3k views

What is the chemical structure of H₂SO₄?

I was looking at the chemical structure of H2SO4. Intuitively, I would have expected this molecule to be square planar in a p2d2 or sp2d geometry but rather, it is shown to be in an tetrahedral ...