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
70 views

Distribution of polymer lengths

Suppose we have a chemical reaction where a linear chain can form (reversibly) from building blocks (e.g. atoms or molecules): $$\ce{X_$i$ + X_$k$ <=>[$k_\mathrm{fwd}$][$k_\mathrm{rev}$] X_$i$...
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1answer
841 views

Reaction of alkyl halides with strong unhindered bases

Please look at the image on this website: http://www.physicsforums.com/showthread.php?t=765853 For (b) and (c), what the solution manual says makes no sense to me. You're reacting a primary alkyl ...
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1answer
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Product of Friedel-Crafts cyclisation of (3-methylpent-4-en-1-yl)benzene

My proposed mechanism and final product is: But the book says the answer is: I know that a 6 membered ring is more stable than a 5 membered ring so I made the product with the 6 membered ring (...
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391 views

What are the products A and B in the following reaction?

What are the products A and B in the following reaction? According to me, the $\ce{NH2^-}$ anion being a strong base would form an alkoxide ion. But since there are 3 $\ce{OH}$ groups it will ...
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1answer
205 views

Is the following rate law possible for the given reaction?

A researcher is investigating the following overall reaction: $$\ce{2C + D -> E}$$ The researcher claims the rate law for the reaction is written as follows: $\text{Rate} = k[\ce{C}][\ce{...
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1answer
161 views

Is isobutyl chloride or ethyl chloride more reactive in an SN1 reaction?

Compare the rate of $\mathrm{S_N1}$ reaction in the following compounds: We see that both compounds form primary carbocations. However, there is more hyperconjugation in the second compound as ...
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48 views

What reaction makes sodium silicate harden in CO2

I have looked all over the web, and I can only find information stating that it does happen. I don't doubt that I just can't figure out what is happening. Some sources state that an acid can cause the ...
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15 views

Where can I find equilibrium constants for a specific reaction? [duplicate]

I'm doing a project on the production of dap fertilizer, but I can not find a database with kinetics constants(reaction rate constant.) It's based on TVA Process for production of granular diammonium ...
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1answer
107 views

Mechanism of Fritsch–Buttenberg–Wiechell rearrangement

The following reaction was given, which uses potassium t-butoxide. The solution to this problem was given as follows: Step 1 is the attack of strong base, t-butoxide, on the vinyl proton. Step 2 ...
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1answer
17 views

When will acid-base reactions occur before substitution reaction

For example, given the reaction below: The substrate is secondary, the solvent is aprotic and it is to react with a strong bulky base. From this, I assumed that the reaction would be $\ce{E2}$. ...
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Why does the following “Battery” experiment work?

I did the following experiment: Experimental setup: Two electrodes (one made out of Iron,the other made out of Copper) are put into a (bluish) Copper(ii) sulfate lotion. Then, one connect a ...
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1answer
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Regarding common preservatives and their effect

If someone has an average of 1 litre of Coke or Pepsi a day, would this form too much benzene oxide in the person's body or stomach and eventually effect part of their genetics?
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1answer
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How does hyperconjugation explain stability of partial positive charges?

Recently I was reading this answer to the question Why does boron add to the less substituted carbon in the hydroboration of an alkene?. See the transition state given in the above answer, and the ...
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1answer
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Curly arrow mechanism for reaction between sodium borohydride and water?

I was asked to compare the reaction between sodium hydride and water and sodium borohydride and water. I know that the former acts more violently than the latter, but apparently, I must use a curly ...
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1answer
830 views

Neighbouring group participation with and without retention of configuration in nucleophilic substitution of 2,6-dichloro-9-thiabicyclo[3.3.1]nonane

Treatment of the dichloride A under the conditions indicated gives B with retention of configuration, while treatment of dichloride C gives D with inversion of configuration. I am having ...
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Does a non-chiral substrate (2-bromo-2-methylpropane) also form two products via an SN1 mechanism?

If I have an alkyl halide, in which its tertiary carbon is non-chiral (for example 2-bromobutane), which reacts via an SN1 mechanism does it also produce 2 products? I am asking because I know that ...
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2answers
12k views

What is the mechanism of the Clemmensen reduction?

I have learned that we can reduce a ketone to an alkane using the Clemmensen reduction, where we treat the ketone with amalgamated zinc in the presence of $\ce{HCl}$. My book didn't mention the ...
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Reaction of phenol and zinc dust

There is a reduction reaction of phenol with zinc dust which is found in many books. $\ce{Ph-OH + Zn -> Benzene + ZnO}$ However, a simple google search fails to explain anything about the ...
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1answer
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Why primary alcohol follows SN1 mechanism?

Example 2: Identify all the products formed in the following reaction and indicate the major product. Solution: Three products will be formed in the given reaction as shown below: In ...
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2answers
951 views

Haloform reaction with limited bromine

We were asked the reaction between 1 mole acetone and 1 mole $\ce{Br2}$ in basic medium. Since only a limited amount of bromine was given I got the final answer as 1-bromopropan-2-one (mono bromo ...
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1answer
113 views

Methyl Orange Indicator-Reason for small amount of NaOH [closed]

I used methyl orange as my indicator to titrate a weak acid: At first, I added 3 drops of methyl orange to a solution of the weak acid, $\ce{CH3COOH}$, and the solution turned red. Then, after ...
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2answers
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Mechanism of a cyclization reaction - why does an enol ether form?

I was asked to predict compound A from the follwing organic scheme: Looking at the formation of A, my prediction was that since TsOH is a strong acid, it would dehydrate the alcohols (like sulfuric ...
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1answer
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Carbocation rearrangement with expansion of five-membered ring?

I am confused with this particular problem. I began the problem with a mechanism as following. In the beginning $\ce{H+} $ protonates the alcohol and leaves as $\ce{H_2O}$. Then everything is about ...
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Why does the reaction with copper and nitric acid change with concentration? [duplicate]

Depending on the concentration of nitric acid, copper undergoes two distinct reactions. For dilute concentrations of nitric acid, the reaction is $$3\text{Cu}+8\text{HNO}_3\rightarrow 3\text{Cu(NO}_3\...
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Reaction Mechanism with a Rate Determining Step

Just a quick question on how to deal with multiple intermediaries in a proposed reaction mechanism. Here is the overall reaction: $$\ce{I-(aq) + OCl-(aq) -> IO-(aq) + Cl-(aq)}$$ Here is the ...
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First order reaction

I am little bit confuse about relating the half life time period of a first order reaction something like $$\ce{2A -> B + C}$$ Here the rate of reaction will be half of the rate at which $\ce{A}$ ...
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3answers
545 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
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1answer
4k views

Why do alpha-hydroxy ketones respond positively to Tollens', Fehling's, Benedict's, Schiff's and HgCl2 tests?

I learnt from a certain textbook that aldehydes and formic acid respond positively to Tollens', Fehling's, Benedict's, Schiff's and HgCl2 tests. However, in another textbook I read that even alpha-...
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3answers
546 views

Simple practical, non-toxic, non-flammable reaction for slow release of CO2

Someone I know (not me) has recently had problems with bed bugs. I have advised him his best bet is to (1) Buy a kick-ass steam cleaner and nuke the brutes from orbit, (2) get a professional pest ...
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2answers
81 views

reaction mechanisms of peroxides

Task: Explain the reaction mechanism of 1,4-Dioxane in terms of how you get peroxides. Start here with the autoxidation with one radical X. My explanation: in the first step 1,4 Dioxan reacts with ...
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1answer
105 views

What will be the order of acidity in the following compounds? [closed]

What will be the order of acidity in the following compounds ? From My point of view it should be 3>1>2>4. But the answer given is 3>2>1>4. Can anyone explain how ?
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1answer
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Required HLB on the Griffin Scale

What is the required HLB on the Griffin Scale of 94% water and 6% mineral oil for producing a stable micro-emulsion?
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Reaction of ketones with sodium amide

Find the product of the reaction of dimethyl ketone i.e. $\ce{CH3C(O)CH3}$ with $\ce{NaNH2}.$ Should I do nucleophilic addition and form the product in the picture?
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1answer
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How to chelate magnesium oxide and l-lysine [closed]

Given magnesium oxide and l-lysine dissolved in water. What needs to happen so that both form a chelate inside the solution.
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0answers
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Halogen bonding in organic reactions

Recently, a group of researchers from the Nanyang Technological University in Singapore have investigated the novel $\ce {S_N2X}$ mechanism which involves a "frontside attack" on the substrate, rather ...
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3answers
6k views

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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0answers
55 views

Why doesn't solvent form the major product in SN1 reactions?

If in a reaction SN1 pathway is followed then after the formation of carbocation the reagent or the solvent molecule can attack to form the product. As the number of solvent molecules are ...
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1answer
34 views

Rate expression for the final product [closed]

Let's say we have: $$ \begin{align} \ce{A &-> B}&\quad&\text{(fast equilibrium)}\label{rxn:1}\tag{1}\\ \ce{2 B + C &-> D}&\quad&\text{(slow)}\label{rxn:2}\tag{2}\\ \...
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1answer
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Observations when mixing potassium Triiodide and Sodium thiosulfate [closed]

I have a reaction equation, it's all balanced but I don't understand what the physical change is. It is as follows: $$\ce{2Na2S2O3 + KI3 \to 2Na2S4O6 + 2NaI + KI}$$ It was used to prove if $\ce{...
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1answer
38 views

Chemical reaction energy barrier width [closed]

Well chemistry before the discovery of quantum world was saying:"In order for a chemical reaction to happen , reactants must have enough energy to be converted into products."I was wondering now that ...
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2answers
53 views

Thermodynamics - Series Reaction - Estimating mols of reactants based on Free Energy of Rxn

Question Three reactions occur simulteneously (assume ideal) at $\pu{T = 0^\circ C}$. $$\ce{A<=>B<=>C<=>D}$$ a) With $\Delta_r G^\circ_\text{AB} = \pu{400 J/mol}$, $\...
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2answers
93 views

Acetone Enolate-HaloBenzene Reaction

A reaction I am trying to perform says to use a strong base like Sodium Amide with Acetone and Iodo-Benzene as reactants with DMSO as the solvent to form Phenylacetone. The main idea is to use the ...
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2answers
39 views

Enzyme Kinetics - Given Km find substrate concentration at a certain velocity

From what I understand about the Michaelis Menten Model Km defines the amount of substrate required to reach half-saturation. 1/2 Vmax corresponds to Km on the x axis Generic formula is v = Kcat [...
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55 views

An unconventional decarboxylation to form bullatenone

I recently had an assessment which required me to draw the mechanism of decarboxylation of a $\beta$-ketoacid. However, it is slightly peculiar because there is the presence of $\alpha$, $\beta$-...
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891 views

Mechanism for synthesis of 4-nitrophenylhydrazine from the diazonium salt of 4-nitroaniline

I am trying to figure out the mechanism to create 4-nitrophenylhydrazine from the diazonium salt of 4-nitroaniline. I've found a couple of explanations for what reactants are used, but I don't ...
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0answers
3k views

Allylic bromination with NBS

I know that NBS is a selective brominating agent especially on the allylic position. And its reaction mechanism is of free radical. But I can't figure out the reason for the change in position of the ...
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2answers
110 views

Why are some reactions exothermic and some are endothermic? [closed]

Some reactions turn out to be exothermic or endothermic. But why does this occur? Why do some reactions need energy to bond but some release energy to bond?
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2answers
7k views

Reduction of oximes with lithium aluminium hydride

I know that $\ce{LiAlH4}$ is good a reducing agent and it donates hydride ions but then I am not able to understand the mechanism of this reaction. I attempted this way I am not understanding what ...
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3answers
84 views

Shouldn't the “law of conservation of mass” prevent equations from being unbalanced in the first place? [closed]

How is it that a chemical reaction produces an equation, that is essentially an impossibility, according to the law of conservation of mass? If the law is true, shouldn't all chemical reactions ...
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0answers
43 views

Why are “diene” structures in the C-ring of anthocyanins singled out for their singlet-oxygen quenching ability?

Anthocyanins are a class of water-soluble vacuolar pigments. They are sensitive to pH, and can undergo a series of structural changes according to a pH-dependent equilibrium as illustrated in Figure 1....