64 votes
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Why does potassium react more violently with water than lithium?

For the reaction, $$\ce{M -> M+ + e-}$$ the heat liberated is highest for lithium owing to its high negative $E^\circ$ value so one would think that the reaction must be most vigorous. The ...
Avyansh Katiyar's user avatar
42 votes
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How does ammonium nitrate explode on its own?

It is known that ammonium nitrate decompose exothermically when heated to form nitrous oxide and water. This paper1 notes that the irreversible decomposition of ammonium nitrate occurs at the ...
Nilay Ghosh's user avatar
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39 votes
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How can I predict if a reaction will occur between any two (or more) substances?

Can I predict the products of any chemical reaction? In theory, yes! Every substance has characteristic reactivity behavior. Likewise pairs and sets of substances have characteristic behavior. For ...
Ben Norris's user avatar
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28 votes

How does ammonium nitrate explode on its own?

Ammonium nitrate ($\ce{NH4NO3}$) is widely used in the fertilizer industry and is one of the most concentrated forms of nitrogen fertilizer (35% of $\ce{N}$). At the same time, it has also been widely ...
Mathew Mahindaratne's user avatar
19 votes
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If aliens lived in a hydrogen (or any flammable gas) based atmosphere, would they perceive oxygen to be flammable?

Absolutely yes. Lighting a torch in such an environment would simply be the reverse physical process (and same chemical process) of what is done in our oxygen-containing atmosphere. In the chamber ...
airhuff's user avatar
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14 votes
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Why are beta-ketoacids better at decarboxylation than gamma or delta?

It has to do with the stability of the electrons that are ejected from the bond that breaks. In B-ketoacids, the electrons can resonate onto the oxygen and form an enol/enolate intermediate, which is ...
TOLA3HPPA's user avatar
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14 votes
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Comparing SN2 reaction rate for phenacyl chloride and methyl chloride

First, let me point out that a rate difference of 500 is really not that large. There are solvolysis reactions with relative rate differences on the order of $\mathrm{10^{10}}$ or greater (1). The ...
ron's user avatar
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14 votes

How does ammonium nitrate explode on its own?

First, ammonium nitrate is a kind of mixture between an oxidizer - the nitrate part - and a reducer - the ammonium one. This is at the core of your question. The direct decomposition correctly ...
Alchimista's user avatar
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12 votes

Rate of EAS in chlorobenzene and fluorobenzene

We need some data to answer your question. As presented in this earlier answer (which is also relevant to this question), here are the relative rates for electrophilic aromatic nitration of the ...
ron's user avatar
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12 votes
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Ambiguous nature of aldehydic group in glucose

The distal hydroxy groups are in a perfect distance to form pyranose (six-membered oxane) or furanose (five-membered oxolane) rings. Any equilibrium reaction that leaves the carbonyl group liberated ...
Jan's user avatar
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11 votes
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Should I expect any surprise when trying to shoot green fireballs like this?

I would not expect boric acid to cause ignition of nitrocellulose. However, boric acid may react with un-nitrated hydroxyl groups on the cellulose backbone--likely a benign reaction. You might need ...
iad22agp's user avatar
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11 votes

Why is oxygen so special?

Dioxygen, $\ce{O2}$ is a very special molecule. A good majority of organisms on earth use dioxygen to breathe and survive. Oxygen is also the second most abundant element in the sky, as well as the ...
Pritt says Reinstate Monica's user avatar
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Reaction of aqueous sodium carbonate with aluminum foil

It is rather: $$\ce{2 Al + 6 H2O + 2 OH- -> 2 [Al(OH)4]^- + 3 H2 ^}$$where $\ce{OH-}$ comes either from hydroxide dissociation, either from carbonate hydrolysis. $$\ce{CO3^2- + H2O <=> HCO3-...
Poutnik's user avatar
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11 votes

Where does the energy required to initially begin the reaction of iron and oxygen come from?

Do all reactions initially require a input of energy? Yes, it is called activation energy. When you say "initially required", it does not mean just when the overall reaction starts. Each ...
Karsten's user avatar
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10 votes

Is there a way to contain fluorine gas for long term so that it can be visually observed?

Here's a slightly exotic, expensive solution: solid, crystaline $\ce{CaF2}$ tubing will do the job. How to get the gas inside, then make a glass seal, is a bit of a challenge though. Surfaces can be ...
uhoh's user avatar
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10 votes
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Why is oxygen so special?

Your question is quite broad, so I will tackle it in parts. Element abundance there is nothing as familiar to mankind (in terms of the frequency in their occurrence) as the reactions involving ...
G M's user avatar
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10 votes
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Which is easier, the nitration of toluene or the nitration of mesitylene (1,3,5-trimethylbenzene)?

The kinetics of aromatic nitration depend on the nitrating method, which also bear directly or indirectly on the subject of nitration. For example, aromatic nitration displays second-order kinetics in ...
Mathew Mahindaratne's user avatar
9 votes

Will bridged compounds the undergo SN1 reaction?

If this compound can undergo nucleophilic substitution, it can only be via SN1 fashion, as the reverse side attack in the anti-bonding $\ce{C-Br}$ orbital is blocked by the other bridgehead. The ...
Martin - マーチン's user avatar
9 votes
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Why does selenophene not undergo aromatic substitution?

The Se atom has such diffuse valence orbitals compared with carbon that there is not good pi overlap, so we don't really have a conjugated cycle. By definition when there isn't a conjugated cycle, it'...
Oscar Lanzi's user avatar
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9 votes

Are there stronger oxidizing agents than fluorine gas?

There are stronger oxidization agents than fluorine gas. I can name two in particular. But I don't think either would actually oxidize fluorine gas in it's pure state, for obvious reasons that you'll ...
orlando marinella's user avatar
9 votes

Why would I not see a reaction between aluminum and tin(IV) chloride?

You need to activate the $\ce{Al}$ to remove the tenacious oxide layer that protects it from reaction. This can be done by a quick wash with dil $\ce{HCl}$, rinse with $\ce{EtOH}$ and finally $\ce{...
Waylander's user avatar
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9 votes
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I can't choose the set of 3 chemicals with each of which Si will react (out of 5 possible sets)

$\ce{Si}$ does in fact react with $\ce{HF}$ and $\ce{NaOH}$. The reactions would be: $$\ce{Si + 4HF -> SiF4 + 2H2}$$ $$\ce{Si + 4NaOH -> Na4SiO4 + 2H2}$$ $$\ce{Si + 2MgO -> SiO2 + 2Mg}$$ ...
Pritt says Reinstate Monica's user avatar
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Why is the alkene a more stable species in this case?

I don’t think that your interpretation is what the author meant. I think that they are comparing the reactivity (or inverse stability) of the alkene to that of the carbocation. I think we can both ...
Jan's user avatar
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9 votes

Why does potassium react more violently with water than lithium?

More than 30 years ago in high school chemistry, our teacher put a flake of sodium in a beaker filled halfway with water and the sodium flitted around the beaker like a little motorboat letting out ...
CramerTV's user avatar
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9 votes
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How does ring size affect SN2 reactions?

TL;DR - Bond angle strain gets a lot worse in going from cyclpropyl chloride to the transition state for the 3-membered ring example, than for cyclopentyl chloride going to the corresponding ...
Organic Chemistry Explained's user avatar
9 votes

Selectivity of diazo-coupling with p-amino phenol

I think the right way to approach this question isn't "we don't know the product, let's try to reason it out from first principles"; rather it should be more like "we found that this is the product ...
orthocresol's user avatar
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8 votes

Why is diene more reactive than alkene?

It is not only the diene itself which is stabilised by resonance, but on electrophilic addition the carbocation formed is also stabilised by resonance if the diene is conjugated. Thus, forming the ...
Aditya Anand's user avatar
8 votes
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Comparing the reactivity towards aromatic electrophilic substitution reaction

We can answer your question by first looking at each individual, unsubstituted position in the benzene ring and determining the relative reactivity at each of these positions. Next we can compare the ...
ron's user avatar
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8 votes

How can I predict if a reaction will occur between any two (or more) substances?

The short answer is NO. There is no single complete theory that is able to predict what products will result from combining a number of reactants. Note that the products of a chemical reaction are ...
Will Esc's user avatar
8 votes
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Can someone explain the unintuitive ordering in the metallic activity series?

The metals in the activity series are ordered by their oxidation potentials; there is nothing random about it. The displacement reactions, though, are but one of the applications of these potentials, ...
Ivan Neretin's user avatar
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