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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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Fuel Cell Water Waste [on hold]

What is the quality of the water produced by a Proton-exchange membrane fuel cell?
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2answers
229 views

Percentage purity of Ba(MnO4)2 sample that completely reacts with given H2O2?

$\pu{40 g}$ $\ce{Ba(MnO4)2}$ (mol. wt. = 375) sample containing some inert impurities in acidic medium is completely reacted with $\pu{125 mL}$ of $\pu{3 M}$ $\ce{H2O2}$. What is the percentage purity ...
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FUNCTIONALIZATION WITH FERULIC ACID [on hold]

I am going to fuctionalize my two different surfaces with ferulic acid. One of the surfaces has OH groups and another surface has COOH groups. Can Ferulic acid covalently attache to these surfaces?
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2answers
820 views

Why can't all electrophiles act as Lewis acids?

We know that all Lewis acids are electrophiles but I have a confusion whether the reverse is also true. Electrophiles are molecules that are in search of electrons while Lewis acids are short of ...
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2answers
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Does Br2/H2O oxidize all aldehydes?

In many books, it is mentioned that aldehydes are easily oxidized even by mild oxidizing agents. However, I have never seen bromine water explicitly mentioned. But in the carbohydrates chapter, it is ...
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Is my mechanism for the reaction, where FabH catalyzes it in fatty acid biosynthesis, complete and correct?

I need to write a mechanism for the following reaction. In this reaction, FabH is the protein that catalyzes the reaction in fatty acid biosynthesis. The beta keto carboxylic acid decarboxylates to ...
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1answer
36 views

what the solution of this problem, negative absorbance values in UV-vis spectrum

In my project, I take the UV-visible spectrum of reaction between pyridinium chlorochromate and N-acetylcysteine. In some wavelengths, the absorbance value is negative for example it is (-0.006, -0....
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1answer
27 views

Mechanism for Bial's test

In biochemistry laboratory, it's common for undergraduate students to perform identification of carbohydrates and its functional groups. Bial's test, a method to check if any pentose is present, is ...
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1answer
849 views

What is trans-addition?

A question from JEE-Advanced(2017) : Bromination of both Z-but-2ene and E-but-2-ene involve syn and anti addition. So, there would be 4 products as suggested in the question. But, I don't ...
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64 views

Attack of 3-methylbutan-1-ol on benzene in acidic medium

That's how I proceeded with the question. However the answer is tert-butylbenzene. I can't figure out why do I have an extra carbon atom. SOURCE - JEE Advanced 1994
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Release of oxygen in reactions of PbO2 and Pb3O4? [on hold]

I have understood that roughly $\ce{Pb3O4}$ is equivalent to $\ce{2PbO.PbO2}$. I have the following reactions to study. Would someone please help me understand the mechanism? Both $\ce{PbO2}$ and $\...
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What is the byproduct of a reaction between copper sulfate pentahydrate, sodium carbonate, and elemental iron when heated? [on hold]

This is entirely a curiosity of mine that requires an answer and not an actual experiment or documented reaction, so far as I can find. I was looking for a professional to inspect/clean a wood stove ...
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Is the Belousov-Zhabotinsky reaction reversible/repeatable? [on hold]

And are there ratios of the ingredients to make it work? I'm currently looking for interesting chemistry experiments for my school open day, hence the formation of this post. If you have any other ...
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1answer
40 views

Reaction mechanism for the conversion of acyl hydrazide to acyl azide

How is an an acyl hydrazide converted into an acyl azide in the presence of $\ce{HNO2}$? According to me, the $\ce{-NH2}$ group of hydrazide will get converted into $\ce{-N2+}$ through $\ce{HNO2}$. ...
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What will be the product here?

In this question, I thought the answer would be 3rd due to methyl shift but as per the solution, it is 2nd. Is it a case of Ethyl shift?
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1answer
17k views

Why super glue does not stick inside their own bottle?

We usually use super glue to stick any two objects but I was wondering like why don't they stick inside their own bottle ?
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21 views

Reaction Of Alkyl Halide with Aqueous Ammonia [closed]

What will be the products of SN reaction of alkyl halide with Aqueous Ammonia. In this reaction which will be attacking nucleophile on alkyl halide, Hydroxide ion or Ammonia?
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1answer
52 views

Friedel-Craft reaction with amide substituent

In this question, I know that aniline will not undergo FC reaction as it forms a complex with $\ce {AlCl3}$ and precipitates out. The answer given is (c) and I agree with it. However, the benzene ring ...
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3answers
56 views

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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Dilute 20 drums of caustic soda solution 50% with 60 drums water to get caustic soda 10% solution [closed]

i want to buy caustic soda 50% solution and then dilute it with water to get 10%. for example; i will buy 20 drums 208 litre per drum and then dilute with 60 drums water to get caustic soda 10%. am i ...
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2answers
84 views

Acidic, Basic, and Neutral Medium

So I'm new to this concept and I can't find any proper explanation to this. What does it mean for a reaction to occur in an acidic, basic, or neutral medium?
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1answer
79 views

Nucleophillic addition vs SN2

The following question came in Paper 2 of JEE Advanced 2014- Here we have $\ce{CH3-}$ as the nucleophile. There are 2 possible attacks: SN2 type attack on the chlorine group. Nucleophilic addition ...
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1answer
54 views

Effect of substituents on Ullmann reaction

This question that I recently encountered asked what the most suitable substrate for the Ullmann reaction would be. The answer given is (b) but I think it has to be (d) as the nitro group acts as EWG ...
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3answers
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Selective nitro reduction of poly nitro compounds

Is there any way through which I could selectively reduce one $\ce{NO2}$ group from a dinitro- or trinitro- compound to an amine. I was reading Solomons and Frhyle and it says that m-dinitrobenzene ...
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2answers
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Perpendicular orbitals in aryl and vinyl carbocations? [duplicate]

This point (iv) has been given under reasons for extremely low reactivity of aryl and vinyl halides. I cannot understand it. First of all, isn't the positive carbon atom in phenyl as well as vinyl ...
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1answer
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Why is the carbanion resonance structure being used in the aldol condensation mechanism?

In the above mechanism's first step, what motivates the use of the carbanion resonance structure of the enolate ion if the negative charge is better localized on the more electronegative oxygen? Edit:...
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JEE 2016 Organic Problem

The following problem is from Paper-2 of JEE Advanced 2016. The answer given to the problem is A. The solution given by various sources suggests an Aldol addition, followed by a cross cannizaro in ...
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2answers
71 views

How does di-isobutylaluminium hydride ( DiBAl-H ) reduces carboxylic acid

$\text{DiBAl-H}$ reduces by electrophilic attack and provides hydrogen by $\text{H}^-$ transfer. Unlike $\text{LiAlH}_4$ it does not directly provide $\text{H}^-$ ion. So it should not undergo acid ...
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0answers
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most frequently used organic (name) reactions

The situation: Beside the relevant inventory in the Merck index, organic-chemistry.org lists 243 name reactions (as counted on 08-Feb-2018), the compilation by Kurti and Czako includes "250 selections"...
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1answer
15k views

Reaction between sulfur and sodium hydroxide

Sulfur reacts with sodium hydroxide in the following way: $\ce{3S + 6NaOH->2Na_2S + Na_2SO_3 + 3H_2O}$ It is a disproportionation reaction: sulfur's oxidation changes from zero to -2 in sodium ...
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3answers
4k views

Which compound reacts faster in the Cannizzaro Reaction?

Which reacts faster in the Cannizzaro Reaction? a) $\ce{OHC-C6H4-NO2}$ b) $\ce{OHC-C6H4-OCH3}$ Obviously, a better hydride releasing group will react faster. Therefore my answer was b, as $\ce{-...
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1answer
485 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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Coal, once burned creates many substances. How to separate?

Could we expose the smoke to different substances reactive to substances in the smoke, that will create a liquid or solid substance, in order to separate, for instance carbon monoxide, from the ...
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57 views

Acid catalyzed enolization and alpha hydrogen

In acidic catalyzed enolization of butan-2-one: We have 2 alpha hydrogens available. From the mechanism of acid catalyzed enolization there is a certain carbocation character at the carbonyl carbon ...
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2answers
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Order of Nucleophilicity

I know this question has been asked many times but I need to confirm this doubt which has been pestering me for the past few days. Suppose in an $\mathrm{S_N2}$ reaction (in polar aprotic solvent) we ...
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1answer
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Bond cleavage of 3 membered cyclic ring on heating

I was told to propose a mechanism for the following conversion: One obvious step is the conversion of cyclic ketal to ketone because of acidic conditions. But I am unable to understand how the three ...
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1answer
7k views

How is benzene prepared from acetylene?

The mechanism of this polymerization reaction which finds its utility in the preparation of benzene in a red hot iron tube piques my curiosity. I've read this Wikipedia article on cyclotrimerization, ...
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How does the inductive effect, explain the reactivity of tertiary alcohols with halogen acids?

The reactions of primary and secondary alcohols with halogen acids ($\ce{HX}$, where $\ce{X}$=halogen) require the presence of a catalyst, $\ce{ZnCl_2}$. With tertiary alcohols, the reaction is ...
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1answer
42 views

Fragmentation involving formation of enamine

I have a problem on fragmentation which requires mechanisms involving formation of an enamine from a cyclic ketone and cyclic secondary amine. This then reacts with a cyclic aldehyde via conjugate ...
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2answers
85 views

How do dibromopyrazolones undergo base-promoted decomposition?

I was not sure but seeing the base as NaOH I used the fact that it will take most acidic hydrogen that is N-H and electron pair will come over it and it will resonate from two sides. I could make upto ...
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127 views

Is the Friedel-Crafts alkylation of benzene with cyclopropenyl chloride feasible?

Is the Friedel-Crafts alkylation of benzene with cyclopropenyl chloride according to the following scheme feasible? Would the attack of the benzene towards the cycopropylium take place? I am ...
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Grignard Reagent in THF vs in Diethyl ether

While learning about the Grignard reagent I was taught this by my teacher, but I couldn’t justify why it was so.. I cannot see how Grignard reagent would react differently in basically an ethereal ...
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1answer
62 views

High concentration of ferric ion catalyst decreases rate of decomposition of hydrogen peroxide in the Fenton reaction

I did a project on the Fenton reaction and rate of decomposition of $\ce{H2O2}$. I used colorimetry to measure the rate of decolourisation of methylene blue when I mixed $\pu{5e-6 mol}$ $\ce{FeCl3}$ ...
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39 views

Steric Factors on reaction with grignard reagent

I was asked to find the products X and Y. For the product X,Here the grignard reagent and even the carbonyl substrate was too sterically hindered to approach the carbonyl center so no reaction would ...
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1answer
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Simple soda–lime decarboxylation

This is my homework question I tried it hard the question is as follow: I attempted it as follow: According to my understanding as acid base reaction are fastest the carbanion will gain a $\ce{H+}$. ...
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1answer
150 views

Nucleophilic addition of grignard reagent

Here why isn't the phenyl group attacking the carbonyl carbon? Isn't the first step in addition of grignard reagent the attack by the carbanion on the carbonyl carbon ?
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2answers
195 views

Do all decomposition reactions involve heat? [closed]

When water decomposes into Hydrogen and Oxygen as in 2H2O—-> 2H2+O2 does this involve heat? Is it always implied that heat is involved in a decomposition reaction or does this just spontaneously occur?...
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Kolbe's electrolysis of acetylenedicarboxylic acid

I have been wondering what this reaction would lead to? The ethyne diradical can't dimerize because triple bonded cyclic structures don't form until 8 carbons. And even if it polymerizes I find no way ...
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1answer
67 views

Probability of the single molecule reaction to happen

I am trying to simulate the single particle second order reactions with known rate constants $k_1$ and $k_{-1}$ in Python. The point of this simulation is to fit the real experimental data to the ...