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.
4
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1answer
330 views
Is the electrophile in sulfonation of benzene SO3 or SO3H+?
What's the electrophile in sulfonation of benzene? Is it $\ce{SO3}$ or $\ce{SO3H+}$?
According to what my professor taught me, both $\ce{SO3}$ and $\ce{SO3H+}$ may be the electrophile involved - and ...
-1
votes
1answer
60 views
Are there any process and catalyst for convert CO2 and H2O into CH4 and O2 [duplicate]
The equation is simple
$$\ce{CO2 + 2 H2O -> CH4 + 2 O2}$$
Yet, is it possible? Are there processes like heat, pressure, electricity, laser and/or any catalyst that could do this process directly?
...
1
vote
1answer
36 views
Which chemicals can counter the corrosion of tamperproof hardware encryption chips?
I'm moving from software implementations to hardware. I need to reverse engineer silicon chips, though the tech that I want to study may have a corrosive chemicals that's supposed to destroy the chip ...
0
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1answer
39 views
Hill function and stoichiometric matrix: confusion about reaction rates
When deriving the Hill function (protein $X$ and $n$ molecules of the signal $S$), my book introduces the following rates:
$$
\text{collision rate} = k_{ON} \cdot X_n \cdot S^n\\
\text{dissociation ...
5
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0answers
152 views
Why are two three-membered rings preferred to a single five-membered ring in the reaction of a dihalide with alcoholic KOH?
The given answer is 1,1-dicyclopropylmethanone:
Step 1 is abstraction of acidic H by the strong base. Then, there's surely going to be anchimeric assistance. But there can be two places where the ...
4
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1answer
125 views
Is E1cB possible in the reaction of cyclopentadiene with acetone in presence of ethanolate?
When cyclopentadiene 1 and acetone 2 are reacted with sodium ethoxide in ethanol, what product is obtained? I was told that the correct product 3 is formed by nucleophilic addition of cyclopentadienyl ...
-1
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1answer
64 views
Rearrangement of 8a-ethyl-1,3,4,8a-tetrahydronaphthalen-4a(2H)-ol [closed]
really sorry for that previous post. I was actually half-asleep when I posted that q, hence the q was unclear. I am again reposting that question
The answer is given as A. Can anyone please explain ...
0
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1answer
82 views
What happens to the chlorine in epichlorohydrin when a two-part epoxy is air-cured?
Where does the chlorine go? Does it evaporate as a by-product or does it remain in the epoxy? I'm using a two-part resin and hardener and curing them at room temp. The resin is bisphenol-A-...
1
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0answers
96 views
Mechanism of heterocyclic ring formation
I saw a question here about the mechanism for a heterocyclic ring formation: What is a reasonable mechanism for the following reaction?. I tried solving the mechanism but I am missing something. Let ...
2
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2answers
231 views
What is the mechanism for the oxidative cleavage of diketones via permanganate under basic/hot conditions?
The products of the reaction are carboxylates.
What exactly would cause the alkyne to cleave?
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0answers
20 views
Predicting which bond breaks during homolysis to generate free radicals
Given is the tertbutyl hypochlorite compound.
On homolytic cleavage of a particular bond in the compound, two radicals will be generated. How can one predict which bond in the compound will cleave ...
0
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2answers
78 views
Reaction involving opening of epoxides
The following question was asked in an exam today:
I chose the option (a), but the correct answer given was (b). Following is the explanation why I chose (b):
Step 1 (Reaction with $\ce{PBr_3}$): $...
1
vote
1answer
44 views
Would this be a reasonable mechanism for the formation of a diazomethene?
I am mostly concerned about the first step. Are there any species in this mechanism that look too reactive for this mechanism to make sense? Any thoughts would be greatly appreciated.
0
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0answers
40 views
Trisubstitution on phenol [duplicate]
Why does tri substitution occur on phenol when bromine water(bromine in any polar solvent) is added to it? Shouldn't the bromine deactivate the benzene ring hence preventing further substitution?
3
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2answers
1k views
In Reimer-Tiemann reaction why does phenol attack the carbene from ortho position?
From the Wikipedia article on Reimer-Tiemann reation:
In step 5, why doesn't the oxygen attack the carbene. The way I see it: upon attacking the carbene from ortho position, the mechanism ...
-1
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1answer
155 views
Why does hydrolysis of OF2 give a neutral solution?
I found this equation on the internet for the hydrolysis of $\ce{OF2}$: $\ce{OF2 + H2O -> HF + O2}$. So, according to me, $\ce{HF}$ must make generate an acidic instead of neutral solution.
But ...
1
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3answers
194 views
How to determine if an unknown is potassium chloride or potassium bromate?
In class, we were given unknown substances. I've narrowed the possible substances down to either potassium chloride or potassium bromate.
We were given several acids, indicators, and other chemicals (...
0
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1answer
103 views
Last step of nicotine extraction using DCM
After using hydro-distillation method with distilled water and NaOH, separating the extract with dichloromethane, distillate it at 40 °C/104 °F, I'm left with some yellow pale oil.
I'm just wondering ...
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1answer
60 views
Combustion/dispersment of mercury (Hg) [closed]
recently tuning a motorcycle using a manometer that contained liquid mercury. Small amount probably a little more than a thermometer but not much more. Unfortunately the meter was upended and the ...
-1
votes
2answers
91 views
How to balance redox reactions possessing oxidation number change in multiple elements? [duplicate]
Hello, I am bit confused about balancing these type of redox reactions where multiple elements are involved in oxidation and reduction reactions.
If I try to use half reaction ion exchange method and ...
6
votes
1answer
115 views
How are alkalide ions synthesized?
How are alkalide molecules synthesized, for example, I have read in a paper that the reaction $$\ce{2Na -> Na+ + Na-}$$ is exothermic with a $\Delta H = \pu{-438 kJ/mol}$.
I have also read that in ...
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0answers
163 views
Application of Michaelis-Menten rate law for biological systems
Many computational models that are used to study biological pathways have been built using Michaelis-Menten(MM) equation. MM kinetics has the assumption that the substrate concentration is much higher ...
0
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2answers
211 views
Product of an intramolecular aldol condensation
When nonane-2,8-dione is treated with base, the product 1-(2-methylcyclopent-1-en-1-yl)ethan-1-one forms according to the following scheme: The arrow denotes the hydrogen that is first attacked by the ...
0
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1answer
149 views
Which is more stable Ethyl carbocation or Neopentyl carbocation?
As per my knowledge, hyperconjugation is more dominating over inductive effect, so due to three alpha hydrogen ethyl carbocation should be more stable. In some books, while solving questions I ...
4
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3answers
276 views
Question on assumption in Michaelis-Menten kinetics
In Michaelis-Menten kinetics, it is assumed that the substrate concentration is much higher than the enzyme concentration. In which step of the derivation of the Michaelis-Menten rate law is this ...
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2answers
444 views
KCl + CuCl2 in solution, is there a reaction?
I'm wondering if the reaction of $\ce{KCl + CuCl2}$ in solution (aq) will produce any products (have a net ionic equation/solid precipitate)?
Using the metal activity series, I see that potassium is ...
2
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1answer
120 views
Modeling Belousov-Zhabotinsky reaction using ordinary differential equations
Is it possible to model the BZ reaction using first order ODEs? If so what would these equations be?
Or, is there something about the reaction that needs higher orders?
2
votes
1answer
618 views
Which alkene on heating with alkaline KMnO4 solution gives acetone and CO2?
Which alkene on heating with alkaline $\ce{KMnO4}$ solution gives acetone and a gas that turns lime water milky ?
2-methyl-2-butene
isobutylene
1-butene
2-butene
I know that $\ce{...
3
votes
1answer
83 views
Mechanism for the intra-molecular exchange of an ester and a nitrile group
When the isolated product 4 is treated with sodium ethoxide in ethanol it rearranges to 5 as shown:
My TA says that you need to start with a reverse Claisen at the ketone but I am not quite ...
0
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1answer
80 views
Pinacole Rearrangement through epoxide
This reaction supposedly passes through an epoxide intermediate. Can someone please explain why this is necessary?
Source
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1answer
77 views
Monobromination of napthalene derivative
How does this reaction take place? Why does the bromine attach to that one particular location?
I do know that
since is $\ce{FeBr3}$ is present only 1 $\ce{Br}$ will attach
non-substituted areas of ...
0
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2answers
119 views
Predicting products of chemical equations? [duplicate]
Consider the equation $\ce{2 NaOH (aq) +Cl2 (g) —> NaOCl (aq) + NaCl (aq) + H2O (l)}$. How would one know the products of this reaction? Is there a general way of doing this? I would have no ...
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0answers
103 views
Mechanism for halogenation of alkene using curly arrow notation
From reading online I have seen two different diagrams for the mechanism for the halogenation of an alkene. The first can be found on Wikipedia among other resources (Chemguide.co.uk, for example). ...
4
votes
2answers
143 views
Can the alkyl-oxygen bond in lactones be cleaved in an SN2 reaction?
I understand that nucleophiles typically attack the electrophilic carbonyl carbon of the lactone and open the ring through a nucleophilic acyl substitution. Has there ever been the case where the ...
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0answers
51 views
How can the CO2 released from sodium bicarbonate reacted with HCl lift an alginic raft if the sodium bicarbonate acts first?
In the antacid Gaviscon, sodium alginate reacts with hydrochloric acid and then calcium carbonate to form an alginic raft that is supposed to be lifted to the top of the stomach by the carbon dioxide ...
12
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2answers
374 views
Mechanism of formation of 2-naphthol red dye (aka Sudan 1)
As you can see in the image diazonium can attack at 2 different positions to form different products then why only the first product is correct?
As there are two ortho positions available why does it ...
5
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2answers
159 views
All roads lead to S4N4
Why does thionyl chloride $\ce{(SOCl2)}$ when it reacts with liquid ammonia form a trace of $\ce{S4N4}$. What is the mechanism of the reaction forming $\ce{S4N4}$.
See discussion of sulfur chemistry ...
4
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1answer
103 views
Major product in nitration
My approach was that when the carbon attached was a secondary one, it would have a greater inductive effect compared to the primary one.
Why is the answer 3? Is it due to steric reasons or am I ...
3
votes
1answer
209 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 ...
0
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0answers
35 views
A problem on Gas bubble column
It is known sulphite to sulhate oxidation can be achieved by using H2O2 or oxygen as oxidising agent. If we flow a liquid mixture of sulphite with H2O2 along with air bubble through the solution in a ...
4
votes
1answer
394 views
Does 2-chloro-2-methylpentane react with NaI faster in acetone or water?
Does 2-chloro-2-methylpentane react with NaI faster in acetone or water?
I thought that since it is a tertiary halide it will proceed via SN1 reaction. So it must be faster in water as it is protic ...
5
votes
1answer
402 views
In the addition of HBr to isoprene why does the less stable carbocation form? [duplicate]
According to me, the answer is B as the tertiary allylic carbocation should be more stable. But the answer given is D and in the given solution, the tertiary allylic carbocation rearranges to primary ...
7
votes
1answer
494 views
Reaction of Grignard reagent with primary amines
What does the reaction $\ce{CH3CH2NH2 + CH3MgBr ->}$ form? Does it form a secondary amine or a tertiary amine or an alcohol? I can't find what a Grignard reagent does to a primary amine.
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0answers
69 views
Mechanism of preparation of methylene blue
Methylene blue is prepared by reacting p-amino N,N dimethylaniline with strong acidic solution of $\ce{Na2S}$ and later adding aqueous $\ce{FeCl3}$. In this reaction does the mechanism begin with the ...
3
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2answers
227 views
Reaction of NaOD/D2O with semicarbazone
I managed to solve the question till D but I'm stuck at the last reaction.
I tried to find its solution and the source suggest it as
16
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1answer
375 views
Understanding the synthesis of twistane [closed]
What are the products P and Q?
This was a question in my test series, but I don't have any experience with bridge head compound regarding the cis and trans transformation. I need help understanding ...
0
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1answer
1k views
Reaction of primary nitroalkane with nitrous acid
I was reading the reaction of primary nitroalkane with nitrous acid. I read this reaction
Another mechanism which I saw:
I am now confused whether the first mechanism occur or the second one.I ...
4
votes
1answer
60 views
Does presence of alkyl groups on alpha carbon increase yield of alkane in Kolbe's Decarboxylation?
We know that, during the synthesis of alkanes by Kolbe's Decarboxylation reaction,
the reaction proceeds via a free radical $\ce{R.}$ at the anode.
So, an alkyl group, say methyl, when substituted at ...
1
vote
1answer
119 views
What is the effect of removal/addition of components of a reaction with unequal moles on both at constant volume by le Chatelier's principle?
This reaction is given in my book and the direction of shift of reaction on addition of $\ce{CO}$ and removal of $\ce{CO2}$ at constant volume is asked.
$$\ce{2CO(g) + O2(g) ⇌ 2CO2(g) + \Delta H}$$
If ...
2
votes
1answer
108 views
What are the products formed when phenol is reacted with benzyl bromide? [closed]
What are the products formed when phenol is reacted with $\ce{PhCH_2Br}$ (benzyl bromide)?
I can think of two ways in which the reaction would proceed. One would be the formation of an ether through ...
