Questions tagged [physical-organic-chemistry]
For questions about how organic molecules and reactions are investigated using physical experiments.
87 questions
-4
votes
0
answers
30
views
Binding Short Vegan Collegen Peptides with Protein disulfide-isomerase
I bought some vegan collagen but it is too short to form gelatin after a heat treatment. Will some protein disulfide-isomerase work to bind the collagen together?
0
votes
1
answer
47
views
Can the water in a vegetable get replaced with another liquid without damaging the structure of the vegetable?
I was watching this year's episode of preserving pumpkins in resin by Evan and Katelyn when I had an idea that I am trying to look deeper into. As the title suggests, I am looking for a fluid that by ...
2
votes
1
answer
171
views
Inductive effect explanation with MO theory
Why are alkyl groups considered as 'electron-donating' groups according to MO theory? how can this effect be explained using an MO diagram and how does this explain why some groups are 'electron-...
- 31
-1
votes
1
answer
27
views
Hybridisation/bonding of XRn oxides
PH3 has a bond angle of around 93o, suggesting the s orbital has a minor role in the bonding, with the p orbitals in p-s σ bonding contributing to the orthogonality of the bonds according to Drago’s ...
1
vote
0
answers
25
views
How Do Turing's Reaction-Diffusion Models in "The Chemical Basis of Morphogenesis" Relate to Organic and Physical Chemistry?
I'm reading Alan Turing's "The Chemical Basis of Morphogenesis" and its reaction-diffusion models:
https://www.dna.caltech.edu/courses/cs191/paperscs191/turing.pdf
As far as I understand ...
- 21
1
vote
1
answer
106
views
Precessional frequency in H-NMR
Suppose we have a hydrogen nucleus. Now, let's apply an external magnetic field $B$. As the magnetic field is applied, the hydrogen nucleus undergoes precessional motion about its own axis with ...
- 305
1
vote
1
answer
85
views
Experimental determination of ring strain energy
For my thesis I am looking to expand a part of it to include experimental means of calculating ring strain, thus far I have calorimetry covering heats of combustion and hydrogenation as well as ...
- 19
0
votes
1
answer
77
views
Calculating the Barrier Between Rotamers
There are two stable conformations of a medium-sized organic molecule roughly 5 kcal/mol apart in ground state energies. One is probably the global minimum conformer identified through a conformer ...
2
votes
0
answers
50
views
What is this gel byproduct of acetylsalicylic acid recrystallization?
I did a very simple acetylsalicylic acid synthesis from salicylic acid and acetic anhydride (with phosphoric acid as a catalyst). After rinsing, filtering and drying the product I dissolved it in ...
- 31
3
votes
1
answer
168
views
Electrolysis of benzyl alcohol in methanol
I am conducting following electrochemical experiment on Au wires in organic medium:
I suppose the anodic reaction goes through a benzaldehyde intermediate:
The cathodic reaction is hydrogen ...
- 471
1
vote
0
answers
145
views
Cation/Anion UV-Vis absorption
I want to understand how the ground state absorption of a molecule shifts if an electron is added or removed. I found these two publications 1 and 2 that observe shifts, but both times a redshift, be ...
- 141
0
votes
0
answers
54
views
Energy Decomposition Analysis for SN2 involving ambident nucleophiles and an alkali metal counterion
I am wanting to perform an EDA on transition state structure of the nucleophilic attack of an ambident nucleophile (2 atoms that could be used in nucleophilic attack on the same molecule) on a benzyl ...
1
vote
0
answers
75
views
How can we prevent retrogradation of starch?
Are there any additives which can prevent retrogradation of starch? I have prepared 13% of starch solution along with 2% of NaCl. The results were bit better. The synthesized gel was flowable with ...
- 19
2
votes
1
answer
231
views
Band structure of solids in general
As my last question (Semiconductors and their electronic bands) was badly structured, I decided to elaborate my questions a bit.
As I now know, every solid/liquid forms a band structure, so all ...
- 471
2
votes
0
answers
287
views
Why is cyclohexane more polarizable than benzene?
Looking at figure 4.2 here, we can see experimentaly that cyclohexane is more polarizable than benzene.
Why is this the case?
Intuitively, I would think that because the orbitals in benzene are more ...
- 31
0
votes
1
answer
117
views
Can species with diffrent number of electrons be isoelectronic?
According to IUPAC gold book-
Does this meam that 2 species with diffrent electron number, but same valence electrons, be considered isoelectronic
Say a molecule XY and ZY where X and Z belong to the ...
4
votes
1
answer
213
views
What is the probability the bonds broken with sunlight reforming back?
The maximum wavelength $\lambda$ capable of breaking a chemical bond can be estimated as $\lambda = hc/E.$
UV-A $(\pu{380 nm})$ can break bonds with the energy up to $\pu{315 kJ mol^-1},$ UV-B $(\pu{...
- 425
-1
votes
1
answer
73
views
Reaction Order from Percent Yield?
Referencing this paper, I am trying to approximate the order of reaction for cyclohexane (4a). Trials 1-3 provide the relevant information of mmol changes and corresponding percent yield but I'm ...
-3
votes
1
answer
284
views
If Qc> Kc how can forward reaction can take place
If Qc>Kc then there will be a net backward reaction but still forward reaction will take place. My problem is if Qc>Kc forward reaction will become non spontaneous right. So how can that happen, ...
- 13
3
votes
3
answers
298
views
Is there a quantitative definition of inductive effect?
Usually, Inductive effects are compared using the electronegativities and distances. However, this only works in compounds with similar structures. For example, we can predict the following orders of ...
- 2,364
3
votes
1
answer
443
views
Boiling points of hydro- and fluoro-carbons
I am teaching organic chemistry to a high school student. While discussing Teflon, we referred to the corresponding section in the 10$^\text{th}$ edition of "Organic Chemistry" by Solomons ...
- 2,364
-4
votes
2
answers
306
views
Why is the dipole moment of Anisole less than that of Phenol? [closed]
According to Wikidata, anisole has a dipole moment of 1.38D and according to this page on Researchgate, phenol has a dipole moment of 1.70D.
Resonance in anisole:
Resonance in phenol:
According to my ...
- 35
-1
votes
1
answer
45
views
The edge case of an edge case: Vapor emissions of the descaling agent Sulfamic acid
I am wondering about the following scenario:
What happens if ready bought sulfamic acid descaling (usually 15% cont. + $\ce{H2O}$) is vaporized or at least steam develops while very briefly descaling ...
- 1
1
vote
0
answers
45
views
Does a free radical localized at one atom in a compound make sense or could it be?
In most of our cases, a dot that represents a radical is always considered affiliated to an atom in a molecule, especially when we talk about a reaction mechanism.
However, Levine's Quantum Chemistry [...
- 11
0
votes
0
answers
39
views
If Ethyne has the lowest C-H bond length (highest C-H bond energy) compared to Ethane and Ethene, why is it the most acidic? [duplicate]
I am not an expert in chemistry, but these are the few facts I know from Standard XII chemistry books (these facts could be wrong or incomplete or modified by now).
Facts I know -
Ethane has 'sp$^3$' ...
- 109
1
vote
0
answers
47
views
Better Way for Crushing Coconut into 500 mesh Coal for Carbonization
I am planning to use coconut as a raw material for carbonization, but I need to crush it into 500 mesh coal. Currently, I am using a mortar and pestle to grind the coconut shell into a fine powder, ...
- 19
2
votes
1
answer
370
views
Finding concentration of ascorbic acid
Question:
A person applied following procedure for the determination of ascorbic acid (Vitamin C) in a sample solution.
A volume of 20.00 cm3 of the ascorbic acid sample was reacted with 25.00 cm3 of ...
- 127
0
votes
2
answers
311
views
Find percentage of carbon monoxide reacted using ideal gas equation
Question
A palladium or platinum catalyst was used in an automobile to convert carbon monoxide gas to carbon dioxide according to the following reaction:
$$\ce{2CO(g) + O2(g) -> 2CO2(g)}$$
A ...
- 127
-1
votes
2
answers
99
views
Apparent circularity of the definition of mass [closed]
I am not a chemistry student, so forgive me for the naïvety of the question. The atomic mass of an atom is defined relatively to the mass of 1/12 of the mass of an unbound neutral atom of carbon 12 in ...
-2
votes
1
answer
255
views
Confusion regarding what reduction/oxidation means in reactions having covalent compounds [closed]
In the formation of NaCl, Na gets oxidised because it loses an electron, while Cl gets reduced because it gains an electron.
But how does this concept work in the case of covalent compounds, ...
- 342
2
votes
0
answers
69
views
How do salts affect pH? [closed]
Since pH measures the effective proton concentration, it is the concentration of a very specific type of cation. I know if salt reacts with water, it will affect pH. But my question is, how does the ...
- 29
-1
votes
2
answers
583
views
What will be the product of 1 eqv Benzene reacts with 1eqv H2? [closed]
how equivalent concept is applied in the above problem, Kindly help me out with the answer and proper explanation.
As, I am getting confused in mole concept and equivalent concept here.
1
vote
0
answers
62
views
What happens to polymers under high pressure?
What happens when you have polymers under high pressure? My very sketchy thoughts of polymers are that they can be thought of tangles of carbon chains surrounded by hydrogen, but that some polymers ...
- 119
2
votes
1
answer
463
views
Why doesn't tetrachloromethane react with aqueous sodium hydroxide under reflux?
$\ce{CCl4}$ does not react with hydroxide nucleophile whereas $\ce{CH3Cl}$ does.
I had initially thought that it was due to symmetrical geometry of $\ce{CCl4}$ and so the dipoles cancel out and the ...
1
vote
0
answers
56
views
Why we use various layers in OLED (ETL,EIL,HTL,HIL)? How they increase efficiency OLED device? [closed]
Currently, I am studying the working of OLED devices! The device can work with just three layers which are Anode, Cathode and Emission layers. I know the fact that the work function is an important ...
- 119
-2
votes
1
answer
203
views
Boiling and melting points of hydrocarbons [closed]
What happens while boiling and melting hydrocarbons? Which bonds are broken?
When we compare the boiling point (b.p.) and melting point (m.p.) of certain hydrocarbons the order is inverted. For ...
7
votes
1
answer
1k
views
Fluorine detection in organic compounds
Many of you will know why I am asking this question. There is a lot of attention recently to the dangers of the so called Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS). In essence organic ...
- 187
-3
votes
1
answer
82
views
Why do we need Equilibrium Constant as well as Acid Disocciation Constant? [closed]
I did the experiment to find out the dissociation constant of a weak acid using Henderson equation. However, after going through the theoretical part of the experiment, I am wondering why we need two ...
- 307
-1
votes
1
answer
485
views
Why in calculating 25 mM of Tris HCl the answer in gram is automatically refer to the gram in 1000 ml [closed]
In the lab class,my teacher told me that the answer i get in grams is automatically the grams in 1000 ml.
Why is it possible without we doing anything the grams i get automatically the grams in 1000 ...
0
votes
1
answer
190
views
How does addition of side chains affect solubility and processibility of polyphenylene vinylene?
I am studying electrical engineering and physics. In a recent lecture I was told the $\ce{OC1C10}\text{-PPV}$ molecule has the chains added to the oxygen atom down below because it allows for ...
- 501
3
votes
1
answer
237
views
Comparing rates of substitution reactions
The following question was asked in an exam I gave recently
Compare the overall rates of the following substitution reactions
$$\ce{CH3Cl ->[OH-][Weak P.A.S]
CH3OH}$$
$$\ce{CH3CH2Cl ->[OH-][ ...
- 1,421
2
votes
0
answers
280
views
Why is the enthalpy of formation of 2,2-dimethylpentane larger than that of 2,2,3-trimethylbutane?
Firstly, it is commonly known and taught that branched alkanes are more stable than linear ones, and so have larger enthalpies of formation. But why is that the case? Are there some steric ...
- 37
8
votes
1
answer
251
views
Out of tropolone and tropone, which is more soluble in water?
According to me tropolone has intramolecular H-bonding, so extent of H-bonding with water will decrease and thus, will be less soluble.
Tropone (Cyclohepta-2,4,6-trien-1-one):
Tropolone (2-...
- 89
1
vote
0
answers
40
views
How do electrostatic effects effect facial selectivity in addition to cyclic oxo-carbeniums?
I was reviewing Dave Evans' notes for stereochemistry of C=X electrophile additions, and found this slide detailing differences in additions to cyclic oxo-carbenium electrophiles, but I don't ...
- 31
0
votes
0
answers
357
views
Why does Red Phosphorus react so violently with an oxidizer like Potassium Chlorate?
In Armstrong's Mixture, mixing those two chemicals results in a friction sensitive explosive which produces a loud bang. According to wikipedia, it is made by adding a strong oxidizer to red ...
2
votes
0
answers
56
views
What kinetic model does the hydrogenation reaction of dibenzyltoluene follow?
So during the course of my research, I've read countless papers related to the hydrogenation of dibenzyltoluenen and the dehydrogenation of perhydro-dibenzyltoluene. Now what I've noticed, is the fact ...
- 113
4
votes
0
answers
41
views
Normalising Kinetic Isotope Effect Per Deuterium Atom
I've synthesised a protic and deuterated version of a specific molecule where there are two deuterium atoms in the latter. I then go about and measure the kinetic isotope effect (KIE) for a reaction ...
- 397
2
votes
1
answer
261
views
Small scale gas-to-liquids via Fischer–Tropsch — is it even possible?
I'm really interested in the Fischer–Tropsch gas-to-liquids (GTL) process. A lot of people are using wood or other biomass feedstock to make syngas on small scales (farms, shops, etc.).
Practically, ...
- 31
3
votes
1
answer
190
views
pKa of acetic acid in pure NH3?
Acetic acid completely dissociates in liquid ammonia and I would like to know the $\mathrm{p}K_\mathrm{a}$ value for the acid in that solvent. Can anybody point me to a reference?
2
votes
0
answers
898
views
Comparison of boiling points of para-derivatives of phenol
The boiling points of four para-derivatives of phenol are:
How can we compare the boiling points of p-nitrophenol and p-aminophenol?
Apart from the hydroxyl group, p-nitrophenol has two oxygen atoms ...
- 1,290