Questions tagged [reaction-mechanism]

The detailed (and as complete as possible) description of plausible or observable pathways leading from reactants to products of a chemical process. This tag should be applied to questions about these processes. It may be applied to hypothetical and/or proposed mechanisms.

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1answer
2k views

Relationship between auto-ignition temperature with pressure and fuel

Experimentally it appears that increase in pressure, fuel concentration, and chain length causes AIT to decrease until a minimum where even further increase in these parameters increases the AIT. ...
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How does electrophilic bromination with 1,2-dibromoethane work?

Hi I am trying to figure out the mechanism of a reaction containing a lithium carbanion and 1,2-dibromoethane in THF. The lithium carbanion is generated by deprotonating using LDA. Then 1,2-...
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How to get the enthalpy of a reaction from the enthalpy of formations with Hess' law?

Let's consider a generic reaction: $$\sum_{i=0}^{i=I}n_{i}A_{i} \rightarrow \sum_{j=0}^{j=J}m_{j}B_{j} $$ where $n$ and $m$ are the stoichiometric coefficients, while $A$ and $B$ are reagents and ...
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Last step of proposed cubane synthesis

I was watching an online lecture on decarboxylation by soda lime and the first few examples were straight forward but after a while a felt that the questions couldn't simply have one effect and maybe ...
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What is the order of [H2SO4] with regards to the reaction H2SO4 + CaCO3?

What is the relationship between the concentration of sulfuric acid and the rate of reaction of $$\ce{H2SO4(aq) + CaCO3(s) ⟶ H2O(l) + CO2(g) + CaSO4(aq)}$$ in the rate law: $$\mathrm{rate} = k[\ce{...
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1answer
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Rate of reaction- Arrhenius equation [closed]

Can the Arrhenius equation be used if the reactants are in the solid state and if I can use it for any state, how do I do so?
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1answer
37 views

Can Michaelis-Menten constant be zero in the Michaelis-Menten Equation, or is this a non-zero constant? [closed]

Can Michaelis-Menten constant be zero in the Michaelis-Menten Equation, or is this a non-zero constant? I am applying the equation in epidemiology so I wanted to assume that it is zero but I am not ...
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2answers
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Markovnikov Rule of Alkenes

$$\ce{CH3CH(CH3)CHCHCH2CH3 + HBr ->}$$ According to Markovnikov Rule, "the rich get richer". But, as we can see the 2 carbons have the same amount of $\ce{H}$. So, what's probably the answer?
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Why is 1,2-diiodoethane unstable? [duplicate]

Diiodoethane is a product of the reaction between glycol and $\ce{PI3}$. Why is 1,2-diiodoethane unstable?
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Orientation in benzene rings with more than one substituent

Why is it that the chlorination of 1-chloro-3-nitrobenzene (18) gives 1,4-dichloro-2-nitrobenzene (19) as the major product, 1,2-dichloro-3-nitrobenzene (20) as a minor product and 1,2-dichloro-4-...
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What happens to copper(II) hydroxide when it's heated? what's inside its decomposition?

So just wondering, copper(II) hydroxide undergoes thermal decomposition when it's heated. But isn't it a solid by itself too? Why does it turn into another solid and water all of a sudden? Can ...
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Mechanism for the reaction between trisilylamine and hydrogen chloride

In Concise Inorganic Chemistry by J. D. Lee (adapted by Sudarsan Guha), in the chapter "Chemical Bonding", under the topic "Back Bonding with Nitrogen as a donor atom" the following reaction is given: ...
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3answers
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Reaction between NaOH and CO2

So I wanted to know what the reaction between sodium hydroxide and carbon dioxide can be, and upon research I got 2 answers. The first one is $$\ce{CO2 + NaOH(aq) -> NaHCO3(aq)}$$ and the second ...
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Why does alcoholic KOH prefer elimination whereas aqueous KOH prefers substitution?

What is the basic difference between aqueous and alcoholic $\ce{KOH}$? Why does alcoholic $\ce{KOH}$ prefer elimination whereas aqueous $\ce{KOH}$ prefers substitution?
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1answer
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Why doesn't this reaction happen? [closed]

In the synthesis of DMAD, we eliminate two bromides from dibromosuccinic acid in basic environment to get acetylenedicarboxlyic acid (Step 2). However, this reaction could also happen: The reaction ...
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2answers
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In the condensation reaction of an aldehyde with a hydroxyl amine, why is an oxime formed and not an amide?

Condensation reactions are those that involve removal of a water molecule. When you analyze the reaction between an aldehyde and hydroxyl amine, I don't understand why it's not possible for the acidic ...
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Do alcohols react with alkyl halides?

I wonder if alkyl halides react with alcohols or not. I searched on Google but could only find reaction of alcohols with hydrogen halides
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1answer
698 views

Why do disproportionation reactions take place?

I want to know what are the conditions when disproportionation reaction is feasible. Is it just because of stability factors or it has other dimensions to it. As an example: $$\ce{3HNO2 -> HNO3 + ...
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1answer
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What is the mechanism for trans-stilbene to stilbene dibromide?

What is the mechanism for trans-stilbene to stilbene dibromide? This is what I know: The bond between the hydrogen and bromine is broken and the bromine is given a negative charge, while the $\ce{H}$...
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1answer
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The reaction of an oxyacid with water [closed]

I read in my book this: $$\ce{H2SO3 + H2O -> HSO3- +H3O+}$$ while I rather would write (not balanced): $$\ce{H2SO3 + H2O -> 2 H+ + SO3^2- + 2 H2O -> SO3^2- + 2H3O+}$$ I mean I don't ...
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Reaction mechanism of thiol to disulfide oxidation under basic conditions?

I have been looking everywhere for an explanation to a reaction mechanism concerning the oxidation of DTT (or just thiols to disulfides in general) using oxygen as the oxidant. I'm aware that ...
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Esterification of a carboxylic acid and the production of water

In an esterification reaction between a carboxylic acid and an alcohol, a carboxylate ester and water is produced. I found the following diagram online, and my textbook has a similar one as well ...
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1answer
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Type of reaction between (+)-bis salt of (+)-phenylsuccinic acid and HCl [closed]

Im confused about what type of reaction occurs between the (+)-bis salt of (+)-phenylsuccinic acid and HCl. Would this be considered an acid base reaction or a neautralization reaction? MY THOUGHTS: ...
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Nitrosonium ion in the nitration of phenols

Peter Sykes mentions in the book Guidebook to Mechanism in Organic Chemistry (6th ed.) on p. 137 that: Highly reactive aromatic compounds, such as phenol, are found to undergo ready nitration even ...
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1answer
61 views

Nitration of tri-substituted benzene with Acetic acid and HNO3

So I looked it up on the internet and it says that this is to be a nitration reaction. But how is the $\ce{NO2+}$ formed? I simply cant seem to be able to do the first step of the mechanism, that is ...
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How do I judge which is the rate determining step in a combined reaction?

Let us say we have a combined reaction where there are two reactions taking place infact let us take an example. We assume that the reaction is $\ce{CO2(g) +C(s) -> 2CO(g)}$. Now predominantly ...
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1answer
72 views

Reaction mechanism with benzylchloride (KMnO4 and Soda lime)

So I know that $\ce{KMnO4}$ converts any side chain irrespective of chain length to -$\ce{COOH}$ group and Soda lime converts that into the respective alkane. But in benzyl chloride, the alkyl group ...
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What is the chemical equation for penicillin? [closed]

For our chemistry homework, we have to write the chemical equation for Penicillin.
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1answer
248 views

Predicting the product in a series of reactions

I am stuck in finding the final product $\ce{C}$ formed in the following series of reactions: $$\ce{Bu-C#CH ->[NaNH2] A ->[Ph-CHO][H2O] B ->[MnO2] C}$$ where $\ce{Bu}$ denotes the butyl ...
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1answer
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Confusion about the SN1 and SN2 Mechanism

My book says, and I understand, that the $\mathrm{S_N1}$ mechanism is much faster for tertiary alkyl halides than primary. And the opposite for $\mathrm{S_N2}.$ This all makes sense. What I don't get ...
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Which is faster- SN1 or SN2?

We were studying about nucleophilic substitution reactions. My professor said that in general SN1 reactions are faster than SN2 reactions. I am unable to understand that how can we generalise the rate ...
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Can we prepare alkyl Fluoride by Finkelstein reaction?

My book states that: Finkelstein reaction is particularly useful for preparing iodoalkanes. The iodoalkanes are obtained by heating chloro or bromoalkanes with a concentrated solution of sodium ...
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5answers
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Iron chemistry: acetates for ebonizing wood

I have recently been “brewing” what is commonly called “iron acetate” for ebonizing wood, and I'd like to understand the chemistry of the iron/acetic acid reaction, which should be fairly simple, but ...
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On the mechanism of the nitrogen-removal step of the Wharton olefin synthesis

In today’s reaction seminar, the Wharton transposition made an appearance. In our practice case it started from the epoxide as in scheme 1 below as on Wikipedia; Kürti/Czakó (page 482) begin from the ...
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1answer
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Comparison of rate of dehydration of primary, secondary & tertiary alcohols on cyclohexane

Rate of dehydration when given compounds are treated with conc. $\ce{H2SO4}$ is According to me the answer should be $R > Q > S > P$ but my textbook solution gives the answer as R > Q > P > ...
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Stabilizing donor-acceptor interaction between orthogonal orbitals in the SN2 transition state?

For the $\mathrm{S_N2}$ reaction between chloroacetone and iodide, my professor has drawn a donor-acceptor interaction between the iodine lone pair attacking the Cl-substituted carbon and the π ...
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Why isn't iron(III) oxide an effective catalyst for decomposing hydrogen peroxide?

I've been working on a project involving the catalyst iron(III) oxide for decomposing hydrogen peroxide. It barely seemed to produce any oxygen. This YouTube video also seems to suggest that iron(...
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1answer
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Why does a Diels–Alder reaction not occur here?

I have recently come across this organic chemistry problem. I thought it would undergo simple Diels–Alder reaction But it didn't turn out to be. The product to me looks like a nucleophilic attack ...
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1answer
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Role of THF in oxymercuration of alkenes

I am trying to self learn solomon's organic chemistry book, but there is no explanation over why we should use THF in oxymercuration. After a quick search I found out that THF help stabilize in ...
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What is an active centre of a catalyst?

I was studying catalytic poisoning and read that in temporary poisoning, the poisoners are held at active centres by weak forces. What is an 'active centre' in this context?
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1answer
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How can batteries reach equilibrium if the reactions are irreversible?

My book says that the batteries we have considered so far (Daniell cells) have a low life span because they reach equilibrium too quickly. In the next paragraph, it states they are also made by ...
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Super-absorbent Polymers [closed]

I want to cast a cube out of super-absorbent powder (Fake Snow) for an art piece, and make it become shapeless by gradually exposing it to water over 7 days. I have 2 questions: What is the best type ...
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1answer
86 views

Given advancements of computational power an machine learning, how is it still not possible to predict products from chemical reactions? [closed]

Given that it seems every answer to this question is that it is "impossible to predict the outcome of a chemical reaction." Is chemistry just trial and error? Given how fundamental and revolutionary a ...
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1answer
817 views

Comparing SN2 reaction rate for phenacyl chloride and methyl chloride

KI in acetone undergoes $\mathrm{S_N2}$ reaction with (1) and (2). Compare the rates of the reactions. Like many kinds of these questions there are many factors involved. One is the steric ...
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3-step process to make propyl ethanoate from propene

I was asked to make propyl ethanoate from propene in three steps. I have access to the reactions below. Nucleophilic substitution (Both SN1 and SN2) Electrophilic addition Hydrogenation Dehydration ...
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Coupling reaction with reagent Na / Dry Ether

The following question was asked on myPAT website: I started with the solution by assuming Wurtz reaction would take place. And hence, I came with the product shown in option A. I knew that ...
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1answer
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Not a chemist, needs help with a calculation regarding addition of HCl to sodium formate solution [closed]

As stated I am not a chemist, but I need help on a question I have. Assume I have a Formic acid 75% and I add between 5-10 kg to 1.000 liter of water. If I wanted to add sodium formate and HCl 37% to ...
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Why is pyridine used when making tosyl esters from alcohols?

Tosyl chloride is used to make a hydroxyl group into a better leaving group. However, when the reaction of tosyl chloride and an alcohol occurs, a weak base such as pyridine should be used. Why?
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Fluorination of Carbonyl Compounds using Molybdenum Hexafluoride

What is the mechanism of halogenation of carbonyl compounds using molybdenum hexafluoride? How does it work? Here's a reaction I came across: Can we use it for all carbonyl compounds? Are there ...
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332 views

Mechanism for reaction between aluminium and iodine [closed]

What should be a suitable mechanism for the reaction between aluminium and iodine, catalysed by water? In my initial approaches, I had first thought of repeated attacks of the lone pairs of oxygen in ...