The step by step sequence of elementary reactions by which overall chemical change occurs.

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Deamination of Spermidine?

I was making a solution of spermidine, and noticed that Sigma Aldrich warns that spermidine solutions deaminate over time. I tried to think of how that would happen, and made a diagram: Assuming ...
-4
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1answer
42 views

Why do Diet Coke and Mentos react? [on hold]

Why do Diet Coke and Mentos react which causes the rapid formation of foam? It's because of Aspartame and CO2? A Diet Coke bottle, shortly after Mentos were dropped into it:
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2answers
50 views

Is this the correct mechanism of the formation of the nitronium (NO2+) ion from sodium nitrate and sulfuric acid?

I am currently working on a mechanism for forming paracetamol (or N-(4-hydroxyphenyl)-ethanamide). The typical reaction to nitrate the phenol (starting product) is $\ce{NaNo3}$ with a catalyst of ...
5
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2answers
432 views

Pedagogical exercise - How to synthesize methamphetamine

I am asked to synthesize "methamphetamine." Note that there is no configuration designated for this molecule, and methamphetamine refers to a very specific configuration. In any case, here are the ...
3
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1answer
91 views

Bromination Pathways with alkane, alkene, and alkyne substrates

I'm confused about halogenation pathways. From what I understand, there are multiple halogenation pathways. I'll try summarizing them below; let me know if I do anything incorrectly. Halogenation ...
4
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1answer
34 views

Nitrobenzene reduction with (tin) Sn catalyst: Why is C-H bond cleavage preferred over O-H bond cleavage?

I am trying to understand this mechanism for nitrobenzene reduction with $\ce{Sn/HCl}$. I do not understand why it implies that you pull off the $\ce{C-H}$ hydrogen instead of the $\ce{O-H}$ hydrogen ...
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2answers
54 views

Causes of reversible reaction

It is generally said that reactants react so that they can achieve a lower energy state. Then why does a reversible reaction occur in the first place? Since turning reactants into products increases ...
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1answer
74 views

How does sulfuric acid dehydrate sugars?

I know sugars have -OH groups, and that sulfuric acid is a strong acid. What I'm failing to see is how exactly sulfuric acid dehydrates sugars. Does it protonate the hydroxyl groups, making them good ...
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1answer
48 views

Nitration of Aromatic Compounds

I am told by Dr. Klein that in the nitration of benzene, hydrogen sulfate anion acts as the base and deprotonates the sigma complex. My question is why would the hydrogen sulfate anion be doing ...
2
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1answer
33 views

Benzene Halide Sn1 Reaction?

Is such a reaction possible? Will the benzene carbocation be stabilized via resonance? Suppose the leaving group is super electronegative and the environment is protic. What would be a suitable ...
2
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1answer
63 views

Why is the addition of a singlet carbene to an alkene stereospecific? [closed]

Why is the addition of a singlet carbene to an alkene stereospecific, but not when a triplet carbene is added?
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4answers
59 views

How to figure out if the reaction proceeds via SN1 or SN2 mechanism?

I have been assigned with the task of figuring out whether a reaction is $\ce{S_{N}1}$ or $\ce{S_{N}2}$. The information that I have is, that the yield is dependent on solvent polarity. More ...
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2answers
76 views

Acid catalysed mechanism of the addition of alcohols to alkenes

I believe that this mechanism is false. The protonated ether would in my opinion give a proton to methanol rather than $\ce{H2SO4}$ because the protonated $\ce{CH3OH}$ is more stable than ...
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1answer
41 views

Catalytic iodine in synthesis of phosphonium salts

From Clayden et al. However, iodine is expensive and a way round that problem is to use a catalytic amount of iodide. The next phosphonium salt is formed slowly from benzyl bromide but the ...
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2answers
29 views

Mercury vapor release from amalgam fillings

What would cause vapour release from elemental mercury? Would it be pressure, friction... could one stop the vapour release through cooling the mercury?
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1answer
41 views

2,2,6,6-Tetramethylpiperidine - Bronsted Basicity

I understand that this molecule can only act as a Bronsted base because it is sterically hindered by its multiple methyl groups. However, isn't the proton bound up in solution? Doesn't that ...
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1answer
31 views

Ethene to ethanol: electrophillic additions involving ethyl sulfates

http://www.chemguide.co.uk/mechanisms/eladd/symh2so4.html I was reading my textbook and this website. I just cannot find the mechanism for what happens when we go from CH3CH2OSO3H to ethanol by the ...
5
votes
3answers
87 views

Synthesis via Sn2/Sn1, E2, E1: Choice of solvent

I uploaded pictures on http://www.physicsforums.com/showthread.php?t=765106 I was looking at the answers in my textbook. They seem to make incongruent choices of solvents. In e) and j), why choose ...
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1answer
20 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
19 views

Can anyone explain the reaction mechanisms of these synthesis?

Can anyone explain the reaction mechanism of the following synthesis ? 2NH4Cl + Ca(OH)2 --> 2NH3 + 2H2O + CaCl2 (NH4)2SO4 + 2NaOH --> 2NH3 + 2H2O + NaSO4
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2answers
63 views

Mechanism of reduction by elemental sodium

How exactly does sodium form an alkoxide from an alcohol? I understand the general idea - sodium has a low first ionization energy. Sodium can thus give up its electron to something that'll take it. ...
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1answer
25 views

Why does charcoal absorb smells from the air, and where do those smells 'go' once absorbed?

I've read that using blocks of charcoal can remove some odors from the air by placing them in the vicinity of the odors. (Maybe not as efficiently as other forms of carbon, as pointed out in the ...
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1answer
24 views

Converting cyclic compounds to linear compounds (possible ?)

Can one convert from cyclic convert to linear compound? Like $Cyclohexane$ $+$ $?=Hexane$ Even in High Temp and Pressure? I know it is very tough since we are going from a stable compound to a ...
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2answers
26 views

Reaction between FeCl3 and KI

FeCl3 + KI + H2SO4 = Is it necessary to have the medium acidified , in order to do reaction between FeCl3 and KI ?
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2answers
58 views

What is the result when the polarity of the solvent is increased in nucleophilic substitution?

I read in the Guidebook to Mechanism in Organic Chemistry that increasing the polarity of the solvent slightly reduces the rate of an $S_N2$ reaction. Why does this happen? Another question: We know ...
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3answers
37 views

How to determine order of nucleophilicity among commonly used nucleophiles?

For eg. In Finklestein reaction, NaI(reagent) taken in acetone(solvent) displaces SH(-) ion from alkyl group via SN2 mechanism to form alkyl iodide. But in a separate question we may be asked to write ...
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1answer
44 views

Acid “Catalysis”

I don't follow this reaction. This is after all an acid catalyzed dehydration reaction; why then, is the final product the alkene and water? Water wasn't the original acid. Hydronium ion is the ...
2
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1answer
93 views

Epoxide Ring Opening - Paradoxical Statement

I am told that the nucleophilic chloride anion attacks the tri-substituted location because it has the most partial positive character due to its ability to stabilize positive charge. How does that ...
2
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1answer
64 views

Cleavage of Ethers

Very confused by this video I stumbled across describing the cleavage of ethers with strong acids: From what I can gather, the cleavage of ethers is run in aqueous strong acids such as HI or HBr. ...
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1answer
60 views

Ring Formation and Alkenes

I was consulting Wade and I came across this problem and solution: While I agree with the solution manual, I can't help but wonder if my proposed mechanism is correct. I had the water attack ...
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1answer
65 views

SN1 Mechanism and Allylic and Benzylic Carbocations

My teacher stated that allylic carbocations are comparable in stability to tertiary carbocations. With this in mind I am confused why this MIT practice test states that these two molecules are only ...
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2answers
97 views

SN1 reaction of ethanol at tertiary alkyl halide

I know this undergoes an $\ce{S_{N}1}$ reaction: Ethanol is the solvent. Weak nucleophile. Neutral nucleophile. This points toward $\ce{S_{N}1/E1}$ (competing pathways). The leaving group is on a ...
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3answers
146 views

E2 Elimination; Anti-periplanar beta hydrogen

I'm confused by this picture I found online on a very popular organic chemistry website: (http://www.masterorganicchemistry.com/2012/10/10/comparing-the-e1-and-e2-reactions/) I agree that the ...
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1answer
76 views

Can anyone explain the reaction mechanism of these two synthesis?

Can anyone explain the reaction mechanism of the two synthesis given below ? $\ce{Ar-NO2 ->[\ce{H2/Pd}][\ce{EtOH}] Ar-NH2}$ $\ce{Ar-NO2 ->[\ce{Sn + HCl} \text{ or } \ce{Fe + HCl}] Ar-NH2}$
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1answer
38 views

Reaction mechanism of combustion of H2?

After a discussion about the usefulness of hydrogen fuel for cars with a friend of mine, I wondered what the reaction mechanism for combustion of $\ce{H}_2$ was. I only study (well almost) organic ...
4
votes
1answer
54 views

Difference between nickel catalyst and Raney nickel catalyst

Many times i have seen the catalyst as Raney nickel instead of nickel catalyst. I think Raney is a name of chemist who discovered Raney nickel catalyst.I think Raney nickel catalyst and nickel ...
2
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1answer
37 views

Relationship between rate equation and equilibrium constant

I have read mannaia's answer on the question of 'rate order and confusion', as well as Nicolau Saker Neto's answer to a related question. They have both been very helpful. As I understand, the ...
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3answers
71 views

How to predict the products of a organic chemical reaction [closed]

I want to know how to predict the products of a organic chemical reaction, when the reactants are given. What aspects should I consider when predicting the products ?
11
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1answer
209 views

Why do SN1 and SN2 reaction not occur at sp2 centres?

I was told in my organic chemistry course that $\text{S}_\text{N}1$ and $\text{S}_\text{N}2$ reactions did not occur at $\text{sp}^2$ centres. When I asked why, I was not given a satisfactory ...
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0answers
72 views

What is the mechanism of monofunctional glycosylase catalysis? [closed]

I am learning about base excision repair mechanisms. I understand the main idea how glycosylases are working, but I am trying to understand this in much more detail. I found a paper where they have ...
3
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1answer
111 views

Acid-Catalyzed Hydration

Is there any particular reason why this mechanism is used in the solution manual rather than an acid-catalyzed hydration? I was thinking of having the double bond attack a hydronium ion, which ...
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2answers
46 views

What's the purpose of a Grignard reagent initiation?

Preface: I've read this question about water preventing an initiation from occurring. I understand why it's important to slowly add the alkyl halide to the dry ether and magnesium for exotherm ...
3
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1answer
119 views

Kinetics of Interstellar Chemistry — Applying steady state to formation of H₂

I am trying to solve problem 2 from the 2009 International Chemistry Olympiad (IChO), which is as follows: If two atoms collide in interstellar space the energy of the resulting molecule is so ...
4
votes
1answer
68 views

Why are solids and liquids not included in the equilibrium constant? What about in a reaction rate calculation?

Take for instance the rection $$\ce{H2(g) + I2(s) -> 2HI(g)}$$ The equilibrium constant would not include the solid $\ce{I2}$, but why is this? I have read that its concentration is a constant, ...
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3answers
69 views

Database with organic reaction mechanisms (curly arrows)

Is there any database or book that has an index of organic reactions where the mechanisms are written out, complete with curly arrows? It would really help if I could look up a reaction and see a ...
2
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1answer
104 views

Mechanism for the Beilstein test?

What is a possible mechanism for the Beilstein test for halogens ? I can't seem to find a arrow pushing mechanism for this reaction.
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3answers
88 views

Mechanism for Tollen's classification test for Aldehydes?

I am trying to find a mechanism for the Tollen's Test online but only thing I am finding is balanced equation. Can someone propose or help me find the mechanism ? Thanks !
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2answers
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How does neutralization of free radicals by $\beta$-carotene work?

In my understanding, by bonding to the free radical species, say by one of the double bonds, a new free radical on the $\beta$-carotene develops.
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Acid Bath, Concentration Question

A professor I have gave the class this question, can anyone help? This is the first part of the question. (Also, my professor is from Bangladesh...so yea...) It's the year 2395, and the world is in ...
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1answer
92 views

What happens as an acid is mixed with Sodium Chlorite

I'm told that when Sodium Clorite $\ce{(NaClO2)}$ is mixed with an acid (in a water solution) it produces Chlorine Dioxide ($\ce{ClO2}$) which remains (mostly or partly) dissolved in water. I would ...