Linked Questions

44
votes
2answers
5k 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....
29
votes
4answers
10k views

Why are DCM and chloroform so resistant towards nucleophilic substitution?

In the book Organic Chemistry by J. Clayden, N. Greeves, S. Warren, and P. Wothers I found the following reasoning: You may have wondered why it is that, while methyl chloride (chloromethane) is a ...
23
votes
3answers
2k views

What is Y-aromaticity? Is the trinitromethanide anion aromatic?

The wikipedia article on trinitromethane claims that: There is some evidence that the anion (which obeys the $4n+2$ Hückel rule) is aromatic. Unfortunately the citation is behind a paywall so I ...
7
votes
2answers
10k views

What is the molecular geometry of NHF₂?

I had to draw the molecular shape for $\ce{NHF2}$ as a Trigonal Planar like this But when I check to make sure it was right, I came across a source saying NHF2-difluoroammonia--tetrahedral, ...
17
votes
1answer
14k views

What is the hybridization of the carbonyl oxygen in a carboxylic acid?

My professor sent out a review guide. One of the questions on this guide is The carboxylic acid carbonyl oxygen is: 1. $\ce{sp^2}$ 2. $\ce{sp^3}$ 3. $\ce{H}$-bond donor 4. rapidly ...
13
votes
2answers
14k 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
3answers
23k views

Why the bond angle of PH3 is lesser that that of PF3?

We can explain why the bond angle of $\ce{NF3}$ (102°29') is lesser than $\ce{NH3}$ (107°48') by the VSEPR theory, since lone pair lone pair repulsion is greater than lone pair bond pair repulsion. ...
10
votes
1answer
30k views

Why does SO2 have a larger bond angle than H2O, H2S, and NH3

So we have to find which of the follwing compounds has the smallest bond angle: $\ce{H2O}$, $\ce{H2S}$, $\ce{NH3}$, $\ce{SO2}$. So L $\propto \frac{1}{BA}$ where $L$ is the number of lone pairs and $...
8
votes
1answer
6k views

Is the phenyl cation or ethynylium more stable?

I recently gave an exam and I received an interesting question to which I believe the answer is wrong. Given two compounds, a benzene molecule with carbocation at one of its constituting carbon atoms ...
8
votes
3answers
12k views

Why is the H−C−H bond angle in сhloromethane 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 ...
3
votes
4answers
7k views

What is the CNC bond angle in methyl isocyanate?

Methyl isocyanate, $\ce{HC3NCO}$, is a toxic liquid which is used in the manufacture of some pesticides. What is the approximate angle between the bonds formed by the nitrogen atom in a molecule of ...
3
votes
2answers
5k views

What are the bond angles in cyclohexane?

In the chair conformation of cyclohexane, what are the angles of the triangles defined by: a carbon atom, an axial hydrogen bonded to it, and the midpoint of a vicinal C-C bond ? a carbon atom, an ...
6
votes
1answer
2k views

Comparison of C-Cl bond length in CH3Cl and CF3Cl

How can one compare the $\ce{C-Cl}$ bond lengths in chloromethane ($\ce{CH3Cl}$) and chlorotrifluoromethane ($\ce{CF3Cl}$)? Bent's rule is also consistent with Gillespie's VSEPR model, and may ...
3
votes
2answers
650 views

Comparing bond angles in carbonyl dichloride and carbonyl dibromide

Background I was studying VSEPR and hybridization theory and one of the popular questions in many textbooks was comparison of bond angle of $\ce{NH3}$, $\ce{NF3}$ and $\ce{NCl3}$. $\ce{NF3}$ had ...
3
votes
1answer
103 views

Negative s - orbital chatacter

I am learning about how to calculate s-orbital character. While doing so, I came across a formula $$\cos\theta = \frac{s}{s-1}.$$ For cycloproprane, I used $\theta = 60^\circ,$ and got $s = -1.$ How ...

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