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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3
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1answer
6k views

What happens in the reaction of ammonium dichromate and mercury(II) thiocyanate?

I found this reaction of $\ce{NH4Cr2O7 + Hg(SCN)2 ->[\Delta]\ ?}$ on youtube, and I'm curious as to how it works. I tried searching online, but didn't find much on it. Thanks.
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1answer
237 views

What chemical available in 18th century would explosively react with phosphorus?

For fictional use, I'd like to "construct" a clockwork device featuring phosphorus which could reasonably be expected to: A) glow consistently. B) explode upon some trigger (e.g., influx of air, ...
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1answer
1k views

Effect of vibration on wine quality

Most people that have ever visited a viticulteur (winemaker) will know that it is common wisdom that vibrations are bad for the wine quality. When I was just a kid the winemaker always told me that we ...
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1answer
3k views

Reaction mechanism of imine reduction to amine using an aluminium amalgam

I can not find any good resources on the Internet except for some shady drug syntheses. I was hoping that someone could provide me with some more educational information. I'm interested in imine-...
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3k views

Why does a silane group react with hydroxyl groups?

I read somewhere that a silane group will react with hydroxyl groups. Does anyone know why this would happen?
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1answer
19k views

Why does the unstabilised Wittig reaction selectively form cis alkenes?

This question is meant for a simple unstabilised ylide. The mechanism of the Wittig reaction, as given on ChemTube3d, involves a concerted formation of the oxaphosphetane (this is generally favoured ...
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1answer
10k views

Identifying Reaction Types

I need help on identifying precipitation, acid-base, and redox reactions. I know what each one is in theory: Precipitation: Creating a solid Acid-Base: neutralization Redox: exchange of electrons ...
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3answers
11k views

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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2answers
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A few questions about the conditions of the Diels Alder Reactions

I'm attempting to extract the diels alder reaction into a generic reaction and am trying to gain a better understanding of it. Can a conjugated diene react with another conjugated diene via the diels ...
3
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1answer
2k views

What does reaction exothermicity say about the stability of molecules

If a reaction is exothermic it means that the energy state of the products is lower than that of the reactants so this will be the state that 'nature' will naturally strive for. Often you see that ...
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0answers
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Entropy of activation

In Price & Dwek, I find a small section discussing entropy of activation for three examples $$ 1: \ce{Ce^{4+}} + \ce{EDTA}^{4-} \rightarrow (\ce{CeEDTA})\\ 2, \text{S}_N\text{1 reaction}: \ce{AB} ...
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1answer
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Markovnikov's addition to halogenated alkene?

The justification or rather intuition behind Markovnikov's rule is the stability of intermediate carbocation. The more substituted the carbocation the more stable the product. But based on this ideas ...
3
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1answer
283 views

Degradation mechanism of hydroxymethylfurfural to 2,5-dioxo-3-hexenal and 4-oxopentanoic acid

I want to understand the degradation mechanism of hydroxymethylfurfural (HMF). According to the Wikipedia article, HMF is degraded in honey. Someone said that the degradation proceeds via 2 possible ...
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1answer
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Reduction of carboxylic acids by LiAlH4

I've read that when a carboxylic acid reacts with $\ce{LiAlH4}$ the corresponding alcohol is formed: But when I try to think of the mechanism, I get stuck here: $\ce{LiAlH4}$ produces $\ce{H-}$. ...
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1answer
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Why does the extent of racemisation in an SN1 reaction depend on the solvent used?

Why is it that the extent of racemisation is greater in an $S_N 1$ reaction caried out using a polar protic solvent but the racemisation is not as extensive if an aprotic solvent is used although the ...
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1answer
519 views

How is this an autocatalytic reaction?

I'm probably missing a simple component of this reaction, but for some reason I not seeing it. These are two steps that compose a radical process of the Briggs-Rauscher reaction (that are ...
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1answer
8k views

Result of glucose with acetic anhydride and pyridine?

What is the result when glucose is mixed with excess acetic anhydride and excess pyridine?
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2answers
9k views

What are the factors behind making ice faster?

Recently I saw a video in YouTube about how to make ice in seconds. In this video, salt is added to a glass of water and then a straw is closed from one end and the other side is lit using a lighter ...
7
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1answer
908 views

Common Elemental Termolecular Reactions

Are there any common elemental (single-step) reactions with three reactants? Everything I've found either says that they're very rare, or can be broken down into two bimolecular steps with combined ...
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1answer
23k views

How can I know the colour change of this reaction?

After you react rotundone ($\ce{C_{15}H_{22}O}$) with water it loses all of the double bonds (except the carboxylic bond, $\ce{C=O}$) and gets two of the functional group $\ce{-OH}$ (alcohol). Two ...
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1answer
68k views

How does the reaction Mg + O₂ → MgO occur? [closed]

$\ce{Mg + O2 → MgO}$ Magnesium, oxygen and magnesium oxide form the above equation. How? What do I need to learn to do this? atomic numbers/ valencies?
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1answer
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What is the mechanism for oxidation of ketones by the Popoff's rule?

Ketones are relatively much harder to oxidise, but they do undergo oxidation reactions at extreme temperatures. Our teacher also told us about Popoff's rule which states that, on oxidation of ...
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3answers
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What happens to the oxygen when carbohydrates turn into hydrocarbons?

According to the biogenic theory of hydrocarbon formation, hydrocarbons come from pressurized carbohydrates. I am looking for an explanation of what happens to the oxygen in the process. How could ...
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1answer
600 views

Lithography: Is isopropanol a developer and/or a stopper?

In the ebeam lithography with PMMA resists isopropanol is often used in a mixture 3:1 (IPA:MIBK) as a developer solution. To my knowledge the developing process is usually stopped by putting the ...
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2answers
16k views

Regioselectivity of acid-catalyzed ring-opening of epoxides

Not to be confused with what is the mechanism of acid-catalyzed ring opening of epoxides. What is the correct order of regioselectivity of acid-catalyzed ring-opening of epoxides: $3^\circ$ > $2^\...
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4answers
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Which chemical properties make a substance explosive?

I know that some chemical substances are used as explosives. Amongst the most famous nitroglycerin in dynamite and cyclonite in C-4. Which chemical properties (I suspect that physical properties have ...
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1answer
185 views

Electrophilic Substitution

I need some help in a electrophilic substitution reaction. What will be the major product formed in this reaction and why? I know that (1) Activator wins over deactivator. (2) A powerful wins over a ...
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2answers
2k views

What is the product when Lithium solid is dropped in water?

I am working on reaction predictions for the AP Chemistry and I need some help with this problem. On a practice quiz I tried to use the rule of "Metal + Water = Metal Oxide" so I answered with $\ce{...
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0answers
790 views

Selectivity Coefficients of Ion Exchange Resins - Selectivity Reversal with TDS / Ionic Strength

I'm currently studying ion exchange resins and generally getting a bit stuck on some points of information which I do not fully understand / are not very well explained within the literature. I ...
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1answer
9k views

How can a group be both a good nucleophile and a good leaving group?

I'm reading about $\:\mathrm{S_N1}$ and $\:\mathrm{S_N2}$ reaction mechanisms, and I have a few questions. My book has a couple of tables, one lists a bunch of substances grouped as good, moderate ...
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2answers
2k views

Why does carbocation stability increase in the order 1°, 2°, 3°?

I'm reading about $\:\mathrm{S_N1}$ and $\:\mathrm{S_N2}$ reaction mechanisms. 1° carbocations are unstable to the point of not having been observed in solution, ever. 2° are more stable, and 3° ...
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1answer
816 views

Intrinsic Reaction Coordinate - What does 'Connectivity' really mean?

I am currently in the process of connecting transition state (TS) structures to other minima in order to determine a reaction pathway. Now I understand the basic concepts of this method. You start ...
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1answer
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Reaction mechanism for oxidation of primary alcohol to carboxylic acid

Can someone help me identify the steps for the following reaction? I'd like to keep track of everything that happens. I can't figure out what happens with oxidation in this context, and thus can't get ...
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0answers
456 views

Is there a bifurcation node in the potential energy as a function of reaction progress equation of chemical reactions?

I originally posted a similar question on math.stackexchange.com, but I believe I might have a better chance of having my question answered here after giving it some time. I was thinking about the ...
3
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1answer
129 views

Reaction of haloalkane with hydroxide ions

My teacher gave me the following question: What are the possible products of these reactions? Then, what is the mechanism of those reaction (elimination (E1 or E2) or subtitution (SN1 or SN2)? ...
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1answer
71 views

What is the mechanism of functionalisation of nanoparticle using long chain alcohols

How can long chain alcohols(not thiols) be functionalised on the surface of silver or gold nanoparticles? I have read in an article that Polyvinyl alcohol is used as a capping agent for silver ...
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4answers
33k views

What is the reaction between Magnesium chloride and Sodium bicarbonate?

For some reason it has been very difficult to find the right answer for this question as there's so much conflicting information to be found online. Some mention a reaction where carbonic acid is made,...
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2answers
799 views

Palladium hydride forming water and heat at room temperature

I just read that saturated palladium hydride, $\ce{PdH}$0.7, when exposed to oxygen will generate heat and water on it's surface, $\ce{4 H}$(Pd) $\ce{+O2}$(g) $\ce{\to 2 H2O}$(g, l). What is going on?...
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2answers
2k views

How do the molecules know the future? How do they proceed to form “Most Stable” compound?

I'm tutoring few students for Chemistry. During the course, I many times use the phrase "Out of these possibilities this one is stable. So it is formed". I get questions like, "How do the molecules ...
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1answer
327 views

What would be the mechanism of the given reaction?

Problem: $\ce{A}$ can be? concentrated sulphuric acid alcoholic potassium hydroxide triethylamine potassium tert-butoxide My comments: Option (A): Conc. $\ce{H2SO4}$, is an ...
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3answers
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What will be the major product of of the Wurtz reaction of 3,6-dibromocyclohexa-1,4-diene?

According to me, the answer should be (A) because that's a Wurtz reaction, but the answer given in the book is (B).
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2answers
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Is it possible, chemically, to change a dextrorotatory compound to its levorotatory counterpart?

Is it possible, chemically, to change a dextrorotatory compound to its levorotatory counterpart? E.g., is it possible to change dextrodopa to levodopa?
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1answer
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A first-order reaction at infinite concentration

I have a first-order reaction, for the binding of two molecules, of the form: $\text{k}_\text{f} = \ce{k_1 (M*s)^{-1}}$. What happens at infinite concentration? How is this upperbound typically ...
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1answer
2k views

Chemical software for solving reactions [closed]

I'm looking for a software which can solve chemical equations. For example something like this (given with result): \begin{align} \ce{CH4 + 2O2 & → CO2 + 2H2O} \\ \ce{C3H6 + HCl & → ...
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1answer
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Resonance in carbocation derived from allenes

During a reaction if addition on one of the $\pi$ bonds of an allene (containing even number of $\pi$ bonds like $\ce {H2C=C=CH2}$) takes place then a carbocation is formed. To decide the position of ...
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1answer
587 views

How does Palladium dissociate H₂ so easily?

If I understand correctly, $\ce{H2}$ in the presence of $\ce{Pd}$ readily dissociates as it dissolves into the metal. With the dissociation energy for the $\ce{H—H}$ bond being so large, how is this ...
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2answers
976 views

How does 1,3-dichloro-1,3,5-triazinane-2,4,6-trione (dichloroisocyanuric acid) generate hypochlorous acid when dissolved in water?

Can someone draw the reaction that leads to the generation of HOCl when dichloroisocyanuric acid (structure shown below) is dissolved in water?
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1answer
2k views

If I have a chiral substrate, should I always assume that both enantiomers are present?

Considering the Sn1 reaction of (S)-2,3-dimethyl-3-pentanol, knowing that this molecule has a chiral carbon, should I always assume that both enantiomers are present, and therefore the products of a ...
8
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1answer
557 views

Thiosulphate acidic decomposition

I just came across this reaction $\ce{Na2S2O3 + 2HCl -> 2NaCl + SO2 + S + H2O}$ I was wondering if it was possible to predict the products of this reaction if I didn't know it (or any inorganic ...
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2answers
2k views

How should I identify my leaving group in SN1 reactions if there might be more than one option?

Before I can even begin to contemplate the products of a given SN1 reaction, I need to be able to determine what my leaving group will be, which should be a species with a strong conjugate acid, and ...