Applied to a chemical species, the term expresses a thermodynamic property in reference to a standard, stating that one state is lower in energy than another. The tag should be applied to questions seeking answers with respect to the stability (or instability) of a certain chemical species, ...

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487 views

Really how rare are hydrogen atoms?

Hasok Chang, a chemist, but perhaps more a philosopher recently published the book Is Water H2O? . Chang used the question and an extensive web of arguments ultimately as a platform to support a ...
3
votes
1answer
30 views

Length of C-H bonds in hybridized bonding orbitals

What is the effect of hybridization and double-bond formation on the rest of the atoms/molecules attached to the central atom? For example, in a benzene molecule, the Carbon-Carbon bonds are ...
6
votes
1answer
59 views

Formation of radicals from C-H and C-C bonds

Why do radical mechanisms favor the homolytic dissociation of a $\ce{C-H}$ bond over a $\ce{C-C}$ bond? The $\ce{C-H}$ bond is stronger in magnitude (and it's also slightly polarized), so why would ...
4
votes
1answer
45 views

Ring expansion from a given cyclic carbocation

How will the cyclobutane ring behave in the following case? I initially thought there would be ring expansion to a five membered ring so that there may be less angle strain and a secondary ...
2
votes
0answers
35 views

Benzylic and allylic carbocation stability order

Most books I have read stop at this order : Benzylic > Allylic > Tertiary > secondary > primary However If I want to compare tertiary, secondary and primary benzylic and Allylic carbocations what ...
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vote
0answers
40 views

Basicity order of methoxy anilines

i have been having some problems with the following question, Arrange o-methoxy aniline,p-methoxy aniline,m-methoxy aniline and aniline in increasing order of their reactivities... the answer given ...
3
votes
1answer
32 views

Why are esters meta directors? Can't the carbonyl donate electrons into the ring?

I'm having trouble understanding why an ester is a meta directing/deactivating group. I'm not talking about an ester with its oxygen bound to the ring, like an acylated phenol. I mean the R group is ...
7
votes
1answer
59 views

Why would sulfuric acid turn gray/black?

About 2 years ago I purchased 2 liters of 98% concentrated sulfuric acid. It's in a standard poly bottle with leakproof lids, and originally was clear. Recently I noticed the acids have turned a dark ...
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votes
0answers
18 views

Boiling point and melting point of dihalobenzene compounds [duplicate]

In Dichlorobenzene what explains the boiling and melting point of the 3 structures that can be formed? According to Google The melting point decreases in the order- Para>Ortho>Meta And Boiling ...
2
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1answer
33 views

Ortho para meta stability

When is the para form of a compound more stable than the ortho form? Similarly when is the meta form more stable? I know that for +I effect ortho para are major products and meta for - I effect. ...
2
votes
1answer
404 views

Why is Tin-112 stable, but indium-112 radioactive?

According to Wikipedia, Tin-112 is a stable nuclide, but indium-112 is radioactive (half-life only 14 mins). What is the explanation for this?
5
votes
1answer
50 views

Why is i-butane more stable than n-butane?

I would like to understand the term stability in organic chemistry. We know empirically that i-butane is more stable than n-butane. But why is it more stable? Is it because of formation enthalpies or ...
8
votes
1answer
72 views

Why are inert gas (especially Xenon) compounds powerful oxidizing agents?

I am curious as to why compounds with inert gases, such as $\ce{XeF4}$, $\ce{XeF2}$, and $\ce{XeO3}$ are considered powerful oxidizing agents. I would attribute the phenomenon to the highly oxidized ...
1
vote
1answer
35 views

Relative stability of keto- enol form of acetyl chloride

Why is the keto form of acetyl chloride more stable even though the enol form is stabilized by the hydrogen bonding?
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vote
2answers
80 views

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 ...
3
votes
1answer
72 views

Stabilisation of phenoxide ion

Which one of the following substituents at para-position is least effective in stabilizing the phenoxide ion $\ce{PhO-}$ (a)$\ce{-CH3}$ (b)$\ce{-OCH3}$ (c)$\ce{-COCH3}$ ...
2
votes
1answer
89 views

Why is RS- more basic than RO-?

The basic strength is determined by the ability of an ion or molecule to accept a proton. How do I know whether RSH is more stable than ROH? (R is an alkyl group)
-1
votes
1answer
35 views

What is more stable: a carbonate ion or a sulphate ion?

The sulphate ion has more number of resonance structures than the carbonate ion. Hence, it should be more stable than the carbonate ion. But my book says that the carbonate ion is stronger than the ...
3
votes
1answer
67 views

Hyper conjugation in acetic acid?

While comparing the relative stabilities of acetic acid and formic acid why don't we consider the 3 possible hyper conjugative structures which would stabilize the positive charge on carbon thus ...
0
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0answers
9 views

Why Bari centre is considered as Zero energy level?

Why the degenerate energy level of d orbitals before forming complex is considered zero? what advantages are there for taking the mean of t2g and eg orbitals as zero?
4
votes
1answer
102 views

Why is 2-methylpropene less in energy than its alkene counterparts?

Other isomers include 1-butene, cis 2-butene, and trans 2-butene. Why would 2-methylpropene be less in energy if there is more steric hindrance?
4
votes
1answer
79 views

Is there an experiment that visibly shows the effects of metastability?

I am attempting to create an experiment to show the effects of metastability to a public audience and get people excited about science. More specifically, I am wondering if there is any sort of liquid ...
3
votes
1answer
88 views

Carbocation stability order

I was wondering whether the following order is correct : In the first inequality, how come 9 hyperconjugation dominated resonance effect of benzene ring? In the last inequality doesn't 2 ...
4
votes
2answers
148 views

Which is more stable ? - A carbanion on benzene ring or a carbanion on a vinylic carbon on an aliphatic chain?

I came across a question which asks to work out the stability order for the following species. Can the lone pair on benzene carbanion participate in resonance? - If yes how and how is it more stable ...
2
votes
1answer
59 views

Does resonance overrule hyper conjugation in terms of stability in alkenes?

Which of the following is more stable ? $\ce{CH2=C(CH3)-CH=CH2}$ $\ce{CH3-CH=CH-CH3}$ I was going for answer 2 because it has 6 hyper conjugative effects. I found the answer given to ...
3
votes
1answer
68 views

Which is the least stable trihalide of nitrogen?

Which is the least stable trihalide of nitrogen and why? I have two conflicting theories, one is that fluorine-fluorine electron repulsion will make $\ce{NF3}$ least stable and another is steric ...
2
votes
2answers
74 views

Does the compound KFO₃ exist?

As the compound potassium chlorate exists, is there something as $\ce{KFO3}$? All the other halogenates are mentioned somewhere on the web but what about this? If no, then why?
4
votes
2answers
223 views

Why does SnCl2 occur despite the octet rule?

Shouldn't reaching an octet be any atom's "goal"? However, I've recently learned about cases that are either expanding octets, or have lesser than "enough" electrons for an octet abiding. e.g.: S in ...
6
votes
1answer
95 views

Stability of di-substituted alkenes

Well I know for a fact that cis alkenes are less stable than trans alkenes due to steric repulsions. But what bugs me is the fact that why systems such as 2-Methylprop-1-ene (where I believe steric ...
7
votes
1answer
390 views

Why are triamino compounds so rare?

I was doing a reaxys substructure search for the compound shown on the left below, with the 3 amines on 1 carbon. However, the closest I found were all trinitro compounds like on the right. I would ...
2
votes
1answer
143 views

How to determine number of alpha hydrogens in a cyclic compound?

How do we determine the number of alpha hydrogens in a compound? Where should we start the naming from? For example, In both these structures, I need to determine their stabilities based on their ...
0
votes
1answer
49 views

Resonance in Propenal

I do not understand why the 3rd canonical form of propenal has the oxygen atom donating an electon. Oxygen in electronagetive so instead of taking electrons why is it giving? Maybe this why it is ...
7
votes
3answers
237 views

How does Resonance stabilize a molecule?

How does resonance lower the potential energy of the molecule? Take $\ce{O3}$ as an example.
4
votes
1answer
80 views

C-H Bond Dissociation Energy varies with substitution

What is the reason behind it? "Among sp3 hybridized systems, methane has the strongest C-H bond. C-H bonds on primary carbons are stronger than those on secondary carbons, which are stronger than ...
1
vote
2answers
67 views

A paradox in the philosophy of instability

The heavier the atom, the more unstable it gets, right? That is not true about Uranium and we know it. I wondered why. A brief explanation stated that since more neutrons are there in the nucleus ...
1
vote
1answer
30 views

How to study Sodium hypochlorite stability with materials

first of all I'm not not sure to be in the right stack exchange site, but I'm a material engineering student and this year I have a project: choose a material for a container filled with Sodium ...
2
votes
1answer
54 views

What is lowest energy state, how does an atom gain it and what does it have to do with hybridization?

I understand that hybridisation occurs due to the atom wanting to exist in the most stable state possible, and the most stable state has the lowest energy. What I don't understand, however, is say, in ...
6
votes
1answer
879 views

What kind of chemicals would exist at the heat death of the universe?

As the universe reaches the maximum entropy, presumably only the most stable chemicals would exist. Assume that all the elements haven't turn into iron yet, what kind of chemicals would dominate at ...
2
votes
0answers
50 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 ...
9
votes
2answers
655 views

By what mechanisms can molecules with the same empirical formula be so different?

I understand the difference between empirical and chemical formula. But I always thought that compounds and molecules took their specific shape because it's the lowest energy configuration. How then, ...
5
votes
3answers
998 views

Is a single carbon atom stable?

It is well known that single atom of oxygen is not stable, and it forms $\ce{O2}$ molecule. But elements like carbon form a network of repeated bonds. As answered in another question, last atoms in ...
11
votes
4answers
725 views

Why are DCM and Chloroform so resistant against nucleophilic substitutions?

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) ...
1
vote
0answers
60 views

Is Oxide Anion more stable than O^+

O likes to be negative if charged at all. Most metal oxides are of the form $\ce{A^{x+} O^{2-}_{x/2}}$ (where $x$ is the magnitude of the positive charge and $\ce{A}$ is a metal.) Here, despite the ...
3
votes
2answers
146 views

How can two electrons lie together in an orbital?

Two electron of opposite spin can lie in a single orbital.. But what about the electron-electron repulsion. Okay! I got that the nuclear charge rather the large Z-effective overcome this repulsion by ...
2
votes
3answers
711 views

How does chlorine form more than 1 bond?

How are perchlorate or chlorate or chlorite ions and their respective acids or compounds formed. $\ce{Cl}$ can't form more than one bond but still... $\rightarrow$'Perchlorate ion' ...
2
votes
1answer
88 views

Conformational analysis determining forces

So the determining forces in the conformational analysis (what will be the more stable state and what will be the more excited state) according to my textbook are: Steric interaction Electron ...
4
votes
2answers
689 views

Why is O2 a biradical?

$\ce{O2}$ has a double bond in its normal form. That is $\ce{O=O}$. There are no unpaired electrons in this case are there since there are 2 lone pairs on each oxygen. However 1 resonance structure ...
1
vote
1answer
63 views

Why do all medicines require storage temperatures below 25 °C?

Almost all medicines I buy have storage requirements saying $T\le25^\circ C$. But do they really spoil at higher temperatures? What if they are stored at e.g. $30^\circ C$, which is common at ...
5
votes
1answer
141 views

What stable arrangements of hydrogen-bonded water exist in the range of 4-20 water molecules?

Water clusters made up of various numbers of water molecules have been described. Are all of these structures theoretical? What experimental evidence supports any of these structures? How does the ...
9
votes
1answer
322 views

Is BCl₅ possible?

Is $\ce{BCl5}$ possible? I saw it in book. As far as we can see there is no way to get 5 chlorine atoms with boron.