Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

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.

2
votes
0answers
36 views

Production of oxirane mechanism

Regarding oxirane production developed by Wurtz, is there an accepted mechanism? I carried out a research but couldn't find anything. My approach was this Is that correct?
1
vote
1answer
206 views

Which of the following is most likely to undergo hydride shift?

For the following question the answer is given as option (a) . However both,option (a) and (c) has alpha H atoms and both will form 3° carbocations after rearrangement. So what makes (a) more ...
12
votes
1answer
216 views

Rearrangement with sodium iodide (ring opening)

I'm not able to figure out the mechanism for this reaction. I don't see how sodium iodide in acetone could lead to rearrangement, and surprisingly ring opening! What is this reaction called, if it ...
1
vote
0answers
30 views

Feasibility of Pyrolytic Rearrangement [closed]

I've been asked whether or not the above reaction happens - and if it does, what's the mechanism? I'm really confused, I think it shouldn't happen; but I'd like to confirm with Chem SE, just to be ...
4
votes
3answers
78 views

Equilibrium for very small amounts of reactants

Is there any difference in the concept of equilibrium when it comes down to dealing with extremely small amounts of reactants? Say we have $$\ce{A + B <=> C + D}$$ and $K_c$ is $100,000$. If ...
1
vote
2answers
82 views

How does the equilibrium shift when concentration of reactant and product are increased simulatenously

Before answering my question, take a look at this example $$\ce{2NOCl <=> 2NO + Cl2}$$ Let's suppose I have 2 mol/l $\ce{NOCl}$, 2 mol/l $\ce{NO}$, and 1 mol/l $\ce{Cl2}$ in a closed system. ...
5
votes
1answer
115 views

What could possibly cause a “melting” reaction between vinyl and plastic?

This question was posted in Electronics. Something is really odd about it! What could possibly be causing this "melting" reaction between a common flexible covering (vinyl, apparently) on test lead ...
-1
votes
1answer
44 views

Predicting products of a reaction and balancing [closed]

2BiOCl + NaOH = BiOH + NaCl. This is the reaction where I am trying to get Bismuth Hydroxide as one product and salt. My problem is what is the state of Bismuth Hydroxide? Whether it is BiOH or Bi (OH)...
3
votes
1answer
127 views

Mechanism for conversion of imide to ester with NaH

What is the mechanism of this reaction? My proposed mechanism is shown below, would it work?
3
votes
0answers
261 views

Why does formic acid give positive Fehling's test?

$$\ce{HCOOH ->[\text{Fehling's solution}] CO2 + H2O}$$ The points discussed in a previous question do not account for the fact that formic acid also gives positive Fehling's test since it is not ...
5
votes
1answer
467 views

Reaction of chloroform, resorcinol and strong base

A common reaction used to identify resorcinol (benzene-1,3-diol) in the laboratory is to react it with chloroform in presence of 30% sodium hydroxide (NaOH). A red coloured solution (or precipitate) ...
1
vote
1answer
196 views

Wurtz Reaction with acidic alkyl halides [closed]

My chemistry book says we cannot use alkyl halides containing acidic hydrogen for Wurtz reaction. Why is this so?
12
votes
1answer
766 views

Chemical equation that can be balanced in infinite number of ways?

When I was studying for my chemistry test, I found an equation that illustrates how to get water gas (carbon monoxide + hydrogen) out of methane. It is stated like this: $$\begin{align}\ce{2CH4 + CO2 +...
5
votes
1answer
88 views

Regioselectivity of bromination of alkenes

Recently, in my chemistry lesson, we were discussing the mechanism of the bromination of alkenes. The teacher brought up the involvement of the cyclic bromonium intermediate. She also mentioned that ...
2
votes
0answers
115 views

Reaction of 1,3 Butadiene with HBr in the presence of peroxides

I have learnt that the reaction of 1,3 Butadiene with HBr depends on the temperature as the temperature determines whether the reaction is under kinectic control or thermodynamic control. I believe ...
0
votes
1answer
63 views

Mechanism for formation of Quinol from a Phenolic Ether

What's the mechanism for formation of Quinol from the given phenolic substrate? The reaction seems to be an acid catalysed hydrolysis, but I'm not able to reach the final product. I guess the first ...
1
vote
0answers
50 views

Napthalene - Friedel Crafts Alkylation and Acylation [duplicate]

Where does Friedel Crafts Alkylation and Acylation occur in Napthalene? Are the reactions kinetic-thermodynamic controlled? Here's something I came across - While alkylation occurs at alpha ...
2
votes
0answers
18 views

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, or, are there ...
3
votes
1answer
87 views

Salt used in Perkin Reaction

The Perkin reaction gives an α,β-unsaturated aromatic acid by the aldol condensation of an aromatic aldehyde and an acid anhydride, in the presence of an alkali salt of the acid. Here is an a diagram ...
1
vote
0answers
146 views

Why add NaBH4 slowly to 4-t-butylcyclohexanone in ether solution? [Lab Procedure]

$\ce{NaBH4}$ is to be added slowly to 4-t-butylcyclcohexanone in ether solution according to laboratory procedures, but I am curious as to why that is? 4-t-butylcyclohexanone undergoes reduction with $...
3
votes
0answers
70 views

Mechanism of photochemical hydroamination with LDA

I've recently come across a couple examples of intramolecular alkene hydroamination accomplished by treatment with LDA followed by visible light irradiation (tungsten light bulb):[1,2] I'd assume ...
5
votes
1answer
81 views

How is laughing gas produced in the Nef reaction?

I can't think of a mechanism for this reaction to give laughing gas. Attempt: I used the base to take out the acidic hydrogen at alpha position with respect to nitro group, but that makes the ...
1
vote
0answers
42 views

Order of a complex reaction [duplicate]

Is the order of a complex reaction determined by the slowest step always? Is it so that order of a reaction is determined by rate determining step and since in a complex mechanism, we write elementary ...
4
votes
3answers
130 views

In regard to collision theory, why do molecules have to have the correct orientation in order to react?

Hypothetically speaking, if a reagent in a bimolecular reaction has enough energy to break the bond of the other reagent but is orientated in the wrong direction, why does the bond not break? Does the ...
5
votes
2answers
308 views

Major product in Reimer-Tiemann Carbonylation

Attempt: This is Reimer-Tiemann Carbonylation reaction in which the ortho product is major when phenol is the substrate. Hence, here I expected the ortho product to be major as well as it would also ...
1
vote
2answers
1k views

Acetaldehyde with few drops of concentrated sulphuric acid

Acetaldehyde on treatment with a few drops of concentrated $\ce{H2SO4}$ gives? Attempt: First, I formed an enol intermediate in acidic medium $\ce{CH2=CHOH}$. Then, I performed electrophilic ...
1
vote
1answer
138 views

Haloform Reaction of Furfural

My instructor pointed out that furfural undergoes haloform reaction - I don't understand how. I couldn't figure out the mechanism on my own, and couldn't find much online either. (regarding the ...
6
votes
1answer
98 views

Which chemical reactions don't involve bond breaking?

I recently came across a question in which an option is 'Breaking a chemical bond is the first step in any chemical reaction', which lead me to think of reactions which do not involve bond breaking. ...
1
vote
0answers
48 views

What coefficients can I use in a Reaction-Diffusion Equation?

I am qualitatively analyzing an abstract chemical reaction $A + B \rightarrow 2A$ where $A$ and $B$ are some liquid substances that undergo Reaction-Diffusion with a second order reaction (actually ...
4
votes
0answers
39 views

Meaning of electrochemical vs nonelectrochemical steps

Can someone please explain to me what is meant by an electrochemical reaction step and how it differs from a nonelectrochemical reaction step in the same overall reaction in the context of ...
4
votes
1answer
122 views

Can we predict with any reliability whether a chemical is carcinogenic in people?

I know that some chemical compounds have been known to be carcinogenic in humans. But can we make a reliable prediction of how likely a substance is to be carcinogenic based on the chemical and ...
1
vote
1answer
195 views

What is the reaction of pentane-2,4-dione with chlorine in presence of NaOH? [duplicate]

We know that in haloform reaction alpha acidic hydrogen are substituted by halogen atom. But in the above case we find two acidic hydrogens in between the two keto groups (due to -R effect) which are ...
2
votes
1answer
223 views

Reduction of 2-cyclohexenone to cyclohexanol

Is $\ce{NaBH4}$ a suitable reducing agent for the conversion of 2-cyclohexenone to cyclohexanol? In Clayden (page 506, second edition), I have found the reduction of cyclopentenone to cyclopentanol ...
3
votes
1answer
127 views

Rearrangement of Grignard reagent formed from exocycloproyl vinyl bromide

First, I prepared the grignard reagent then performed nucleophilic addition to the carbonyl carbon and then did hydrolysis. So basically in my product, $\ce{-Br}$ is replaced by $\ce{-CH2OH}$ But ...
-1
votes
1answer
65 views

1,1-Dibromo-2,2,3,3-tetramethylcyclopropane is treated with CH3Li

My approach: The ring is extremely sterically hindered. And also due to ring strain ring gonna break . Here methyl lithium ($\ce{CH3Li}$) acts as a base so it is going to take the most acidic hydrogen ...
1
vote
0answers
67 views

What is the product formed when 4-chlorobut-1-ene is treated with acetic acid?

My teacher did like this forming a really unstable cyclopropyl group but this is the correct answer instead. My question is why the product will be even formed? In the mechanism that my teacher had ...
5
votes
0answers
166 views

Reaction of cyclopropane with hot potassium permanganate

Hot potassium permanganate is usually used as an oxidising agent, and cyclopropane being an unstable three membered ring undergoes reaction with several reagents such as bromine, $\ce{HBr}$, metal ...
3
votes
2answers
298 views

Rate of catalytic hydrogenation of alkenes

What does the rate of catalytic hydrogenation of alkenes depend upon? What'd be the increasing order of rate towards catalytic hydrogenation of the following alkenes, A (2-methylpropene), B (cis-but-2-...
3
votes
1answer
123 views

When does a pinacol undergo dehydration or rearrangement?

What happens when the above pinacol is treated with - (a) conc. sulphuric acid (b) dil. sulphuric acid I'm confused between pinacol rearrangement and dehydration (E1 or E2?), as both possibilities ...
9
votes
4answers
239 views

Is rearrangement possible in cyclic bromonium ion?

I wonder what the product of the above reaction is, that is, bromination of the given alkene in non polar solvent carbon tetrachloride (proceeds through cyclic bromonium ion intermediate). Once the ...
6
votes
1answer
127 views

Mechanism of synthesis of allene

I would like to know the mechanism of this reaction. In my first attempt to the question, I had replaced the two $\ce{Br}$s by $\ce{CH3}$s by $\ce{S_N2}$ of the organometallic compound but the answer ...
1
vote
0answers
27 views

Why is direct addition not preferred in this reaction? [duplicate]

According to HSAB, direct addition is more preferrable in this reaction with the hard carbonyl carbon electrophile and the hard grignard reagent. But answer given in my book is that with 1,4- addition....
5
votes
1answer
317 views

Benzene from cyclopropane-1,2,3-triyltrimethanol in acidic medium

What is the mechanism of this reaction? After performing $\ce{E1}$ thrice I was expecting 1,2,3-trimethylidenecyclopropane to be formed instead. I know it's highly strained but I couldn't adopt any ...
-1
votes
0answers
20 views

Reaction mechanism of 2H_2+O_2->2H_2O [duplicate]

What is the reaction mechanism for the following reaction? $$2H_2+O_2\rightarrow 2H_2O$$ As an aside, there are quite a few books on reaction mechanisms for organic compounds. Could you suggest any ...
0
votes
2answers
119 views

What would be the reaction equation between ammonium nitrate and a powdered metal? [closed]

The SDS for ammonium nitrate says it will react with powdered metals spontaneously. What would be the reaction equation, say with iron or copper? This mixture is used in various pyrotechnics, and it ...
4
votes
1answer
89 views

Cyclisation reaction through hydrazine

The following reaction confuses me - I don't understand how and why it happened (couldn't figure out the mechanism): I thought this is some Wolff Kishner sort of reduction, but the reagents don't ...
8
votes
2answers
1k views

Why does chlorination of toluene stop at two chlorine atoms?

My instructor mentioned a reaction for preparation of benzaldehyde by chlorination of toluene in presence of sunlight to form benzal dichloride, which on hydrolysis gives benzaldehyde. However, I'm ...
3
votes
1answer
44 views

Conjugate addition vs Electrophilic addition

I was just doing an organic chemistry problem from an online source recently, on the topic of conjugate additions (or 1,4-additions). Below is an image illustrating the problem. I chose the upper ...
4
votes
0answers
140 views

Reaction of alpha hydroxyketone with KOH

What happens when 2-hydroxycyclohexan-1-one (an alpha hydroxyketone) reacts with aqueous $\ce{KOH}$? I tried something like Favorskii rearrangement, but it's wrong because OH isn't a good enough ...
6
votes
1answer
871 views

Mechanism of dimedone preparation [closed]

From the Wikipedia article on dimedone, Dimedone is prepared from mesityl oxide and diethyl malonate. I can't really figure out the mechanism for the reaction. Could someone please help me out?