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Questions tagged [reactivity]

Applied to a chemical species, the term expresses a kinetic property in reference to another species. The tag should be applied to questions seeking answers with respect to the reactivity (or unreactivity) of a certain chemical compound, species, molecular entity and/or functional groups. It must not be applied to questions about the stability of certain chemical species.

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37
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5answers
8k views

Why does potassium react more violently with water than lithium?

Recently, I was telling my friends about the violent reaction that takes place when you throw potassium into water. Soon after, a friend of mine claimed that lithium would react more violently than ...
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2answers
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How can I predict if a reaction will occur between any two (or more) substances?

I am new to chemistry and I find it fascinating. I am trying to learn about chemical reactions and I was wondering if there was an easy way to quickly tell if any combination of chemical substances ...
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Why is gold unreactive when only one electron is in the outer shell?

I've been trying to answer my (high school) daughter's questions about the periodic table, and the reactivity series, but we keep hitting gaps in my knowledge. So I showed that the noble gases have a ...
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3answers
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Rationalising the order of reactivity of carbonyl compounds towards nucleophiles

This is immediately following ron's answer from Why is a ketone more nucleophilic than an ester? One of the most simplest questions you can ask, how can you rationalise the order of reactivity ...
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3answers
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Why shouldn't Uranium come in contact with water?

In the documentary about Chernobyl, it was mentioned that Uranium should not come in contact with water, otherwise an explosion occurs. What is the reason for that? What kind of reaction makes it ...
21
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4answers
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Why do Organolithium or Grignard reagents act as nucleophiles and not as bases with aldehydes and ketones

I've read entire Chapter 14: Organometallic Compounds of Francis Carey's "Organic Chemistry" but I still didn't get an answer to my question. Quote from the book: Because of their basicity ...
21
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1answer
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If aliens lived in a hydrogen (or any flammable gas) based atmosphere, would they perceive oxygen to be flammable?

Energy, fuel, and oxygen are needed for a fire to burn. In a hydrogen chamber, if there was a pipe spewing small amounts of oxygen, could you light the oxygen on fire as it began to mix with the ...
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2answers
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Why does superglue ignite cotton?

Cotton is mostly cellulose, a plant saccharide. Superglue refers to a class of cyanoacrylates. What is it about the two that causes ignition? I'd imagine that the cellulose in cotton is in its ...
20
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1answer
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Stability of alkenes tri>di>mono, but how to explain tetra

When we tell students about the formation of alkenes (by elimination for example), we often tell them that reactions will favour the thermodynamically favourable most substituted alkene. Zaistev's ...
20
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1answer
727 views

Carbometalation of alkenes

Alkynes are capable of undergoing carbometalation, e.g. with organocopper reagents: Why don't the corresponding alkenes undergo analogous carbometalation reactions? Is β-elimination the issue?
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Why is it that the least reactive metals are the best electrical conductors?

Silver, Gold and Platinum are amongst the best conductors of electricity, but also the amongst the most unreactive. Since electrical conductivity depends on the number of delocalized electrons (along ...
18
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3answers
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Why does zinc react with sodium hydroxide?

If zinc is less reactive than sodium, then why does it still react with sodium hydroxide?
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6answers
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Will bridged compounds the undergo SN1 reaction?

$\mathrm{S}_{\mathrm{N}}1$ reaction involves only one molecule in the rate determining step. So, the molecule which undergoes $\mathrm{S}_{\mathrm{N}}1$ reaction should be stable when it forms a ...
16
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4answers
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Why is fluorine more reactive than chlorine?

Why is fluorine more reactive than chlorine despite chlorine having a higher electron affinity?
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1answer
785 views

Singlet/triplet oxygen cycloadditions

Why can singlet oxygen participate in cycloaddition reactions while triplet oxygen, on the other hand, can't?
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Why does N₂ react with O₂ to Form NO at high temperatures?

This also raises questions that I have about the Haber Process which produces ammonia ($\ce{NH3}$) from molecular nitrogen ($\ce{N2}$) and hydrogen ($\ce{H2}$). I have heard multiple times that bond ...
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Why is a hydroxyl group more activating than a methoxy group in electrophilic aromatic substitution?

Why is phenol more reactive towards electrophilic substitution than methoxybenzene? Isn't the lone pair on the methoxy group oxygen more available for participating in resonance into the ring than the ...
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2answers
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Why is a ketone more nucleophilic than an ester?

I guess the ester is a weaker nucleophile because it does have an additional oxygen atom, unlike the ketone, that is pulling electrons from the C-O double bond towards the carbon atom (this happens ...
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3answers
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Comparing SN2 reaction rates

I've read in a book that the main factor for determining SN2 reaction rate is steric hindrance. The lesser it is, the faster the reaction. So consider this question: $\ce{KI}$ in acetone undergoes ...
11
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2answers
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Comparing the reactivity towards aromatic electrophilic substitution reaction

In the following pairs of molecules, which is more reactive towards electrophilic substitution reaction? 1) 1,4-dinitrobenzene or 1,3-dinitrobenzene (don't consider the ortho isomer) 2) benzene-1,...
11
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1answer
237 views

Which electronic effects are responsible for the reduction of nucleophilicity of a hydroxy group orthogonal to an ester?

I am facing a similar synthetic problem as Boekman Jr. et al noted in their synthesis of Tetronolide.[1] I will quote their’s rather than disclosing my actual synthetic problem, but note that the key ...
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3answers
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Why is diene more reactive than alkene?

The chemical reduction of 1,3-butadiene with sodium in alcohol gives mainly the 1,4-addition product that is but-2-ene. Under these condition the isolated double bond are not reduced. This suggest ...
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3answers
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Why is tantalum so unreactive?

What is the fundamental argument behind explaining why Ta metal is so inert and does not usually participate in corrosion? I know that it forms a protective oxide, but nothing explains why in an ...
10
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1answer
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Why is phenyl weakly activating?

The susceptibility of a benzene ring to electrophilic attack depends on the type and number of groups bonded to the ring. Activating groups donate/release electrons and increase the electron density ...
10
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1answer
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What does nutella add to the Coke+Mentos reaction?

Inspired by this question on SFF.SE. The Diet Coke + Mentos experiment has been a popular one for a while now, and I've read a little bit about the science behind it. I recently discovered this ...
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How does ring size affect SN2 reactions?

Suppose we have to compare the $\mathrm{S_N2}$ reactivity order for cyclopropyl and cyclopentyl chloride. How can we do that? I think that cyclopentyl should be more reactive towards $\mathrm{S_N2}$ ...
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Is there a way to contain fluorine gas for long term so that it can be visually observed?

Bromine, chlorine and iodine can all be sealed in a glass container for display without the elements reacting with the glass. But if you try to seal fluorine in glass I believe it will react and fog ...
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2answers
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Why is the iodide anion a good nucleophile but a poor base?

The $\mathrm{pK_{aH}}$ of $\ce I^-$ is very low which indicated that it is not favourable for it to bond with a proton. However, why would it be likely to bond with any other atom (mostly carbon when ...
9
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1answer
425 views

Reactivity of different isomers of N2F2

$\ce{ N2F2}$ exists in two forms cis and trans. Today my chemistry teacher tells me that among the two only cis form takes part in reactions and that it is more reactive. But I have read elsewhere ...
9
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1answer
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Why does potassium form peroxides but sodium does not?

As we go down the periodic table, Group 1 alkali metals hold their single outer valence electron more loosely, and so reactivity increases. Below potassium (Na, Li), we can store the metal in oil with ...
9
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1answer
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How does HF dissolve glass?

By what mechanism does HF proceed in dissolving glass? Why is it the only acid that has this capability? Is it because of the small size and high electronegativity of fluorine?
9
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1answer
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How does conjugation affect reactivity?

From this topic on MOs of butadiene vs ethene, it is clear that when two ethene molecules are combined to extend the conjugate chain, the HOMO is raised in energy and the LUMO is lowered in energy. ...
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0answers
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Aza-enolates: why no reaction at N

My understanding is that aza-enolates have an advantage over enamines in enolate-type alkylations because the reaction at N is less likely. As a result, unactivated electrophiles can be used (i.e. ...
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Friedel–Crafts reaction of phenol

Does phenol undergo Friedel–Crafts reactions or does it react with Lewis acids like aniline does?
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Why doesn't copper react with hydrochloric acid while the other metals do?

5) Which one of the following metals does not react with hydrochloric acid? A. zinc B. magnesium C. iron D. copper E. aluminium The right answer must be copper, but why ...
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2answers
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Why is oxygen so special?

Why do reactions with oxygen produce flame (i.e. light), heat and hence a lot of energy? I mean, why only oxygen, why not any other element like nitrogen? What is special about the electronic ...
8
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1answer
548 views

How does steric hindrance cause sulfur hexafluoride to have almost no reaction chemistry?

Sulfur hexafluoride ($\ce{SF6}$) is, according to the Wikipedia page, a hypervalent substance. However, according to the page in regards to $\ce{SF6}$ reactions: There is virtually no reaction ...
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2answers
450 views

I can't choose the set of 3 chemicals with each of which Si will react (out of 5 possible sets)

This is one of the questions used in the Russian State Chemistry Exam. One needs to select the set of chemicals in the second column such that each of them would react with the element or chemical in ...
8
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1answer
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Why are beta-ketoacids better at decarboxylation than gamma or delta?

My book claims that beta-ketoacids and beta-dicarboxylic acids are better at decarboxylating than their gamma and delta counterparts. Why is that? I would assume that since gamma and delta keto-acids ...
8
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1answer
4k views

Does an acetal give a positive Tollens test?

In Organic Chemistry (Wade) there is a question: Which of the following compounds would give a positive Tollens' test? (Remember that the Tollens' test involves mild basic aqueous conditions.) The ...
8
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1answer
127 views

Why is liquid oxygen more reactive than gaseous oxygen?

Liquid oxygen is somewhat hairy to work with, as, if it comes in contact with essentially anything combustible, it has an unfortunate tendency to detonate violently if looked at sideways. Gaseous ...
8
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1answer
189 views

Does chlorine trifluoride react with candlewax?

I've run across references to chlorine trifluoride quite a lot. It pops up fairly regularly on the Worldbuilding SE, and whatever idea people have with it is usually shot down very quickly - For ...
8
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1answer
385 views

Is ruthenium really invulnerable to aqua regia?

Recently, I answered a question "What metals aren't dissolved in/attacked by aqua regia?" in which I finally concluded "ruthenium is resistant to aqua regia in any form at any concentration of ...
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2answers
131 views

Compare rate of hydrohalogenation between 1,2-diphenylethene and 1-phenylpropene

Consider the compounds, (I) - 1,2-diphenylethene and (II) - 1-phenylpropene. Compare their rate of hydrohalogenation (HX addition) I feel that the answer should be (II) > (I), but to my surprise it's ...
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1answer
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Role of methanol in NaBH4 reduction

In reduction of carbonyls (aldehyde and ketones) to alcohols using NaBH4/Methanol, alkoxides are formed with the Boron which usually gets protonated on addition of water/acid. My question is what is ...
7
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1answer
652 views

Ambigious nature of aldehydic group in glucose

In aqueous solution, α-anomer and β-anomer of glucose remain in equilibrium with each other along with a small amount of glucose in open chain form ($0.02~\%$). The open chain form in ...
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2answers
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Order of electrophilic substitution

What will be the order of reactivity towards electrophilic substitution in case of the following compounds: benzene, ethyl benzene, isopropyl benzene, tert-butyl benzene The answer at the end of the ...
7
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1answer
335 views

What are the conditions for liquid metal to be corrosive to another, different solid metal?

I've had already been aware of the fact that metallic aluminum can be degraded by coming in contact with mercury, but also came across another question more recently here explains a similar reaction ...
7
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1answer
202 views

Quantum mechanical (or QFT) description of mesomeric effect

This is rather a question about finding the right literature, since the answer would probably exceed a typical forum post. In organic reactions, mesomeric and inductive effects are of tremendous ...
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1answer
1k views

Bonding of Lithium and Argon

I saw a meme that was joking around about Lithium and Argon bonding (see pic below). It got me wondering: Can Lithium and Argon bond in any circumstance?