# All Questions

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9k views

### Synthesis of Diazepam with (2-amino-5-chlorophenyl)(phenyl)methanone

I tried to draw the mechanism of the diazepam synthesis. Question: Do I really get the tertiary amine or does dimethyl sulfate methylate the amine twice?
2k views

### Distillation for separating very close boiling components

When components of a mixture have very similar Boiling Points, say 2 C is distillation ever a viable separation procedure at industrial scale? Assuming one were willing to install a very tall column,...
624 views

### How do I create a transparent liquid for ferrofluid display?

Hello~ I am a media art artists working in Korea. Recently, create a kinetic artwork using ferrofluid. I need to create an artificial pond with a diameter of 3 meters. So I need a lot of suspension ...
251 views

### correct psilocybin molecular structure

I'm writing a research paper on psilocybin. I need to know the correct chemical structure. When I look online it it shows different ones. There is one with two OH molecules attached to the ...
1k views

### Is the deprotonation of phenol exothermic?

I just wanted to confirm that deprotonation reaction of weak acids are exothermic? I know that strong acids deprotonate exothermically (e.g. adding liquid $\ce{H2SO4}$ to water releases a lot of heat),...
209 views

### Color of methoxy substituted phenyl rings when heated in the presence of acid

Anyone who's familiar with organic synthesis will probably have came across the DMB and PMB protecting groups. When TLC-ing compounds containing these protecting groups using common stains like ...
62 views

### Will molecules containing heavy isotopes tend to rise up in a liquid?

When you have a bag of chips or nuts or something else with big and small pieces and you shake it, the bigger pieces will rise up and the smaller pieces will rise down. This is known as the brazil nut ...
475 views

### (Computationally) finding similarity between two organic compounds

I have been struggling to find an acceptable answer for this question for my purposes. There are many ways to find similarity between two organic compounds - some of which are particularly popular ...
226 views

### Forming a dioxolan with levodopa

I've got 2 problems with reaction: 1) Does the nitrogen or the carboxyl group react with the methanal? Do I have to use a protecting group? 2) Is there a chance it reacts similar to a marquis ...
451 views

### How to make γ-MnO2 in a lab?

I am working on Li-ion batteries, and I need to use γ-$\ce{MnO2}$ (electrolytic manganese dioxide). I have googled and read quite a few papers, but I am not very sure of those methods. I'd love ...
1k views

### Why does the local density approximation (LDA) overestimate atomization energy?

I have read numerous times that the local density approximation (LDA) overestimates atomization energy. For example, here is a quote from Dr. Burke's book: LDA typically overbinds molecules by ...
46 views

### Are phospholipids capable of forming automatically circles or vesicles?

Sometimes scientist think that life began with membrames made of a kind of phospholipids. There wasn't any DNA needed for because those molecules would automatically form vesicles like cells. But is ...
504 views

### Can a Boc protecting group be removed with trifluoroacetic acid?

I am trying to cleave a tert-butyloxycarbonyl (Boc) protecting group from an aminooxy group ($\ce{-O-NH-Boc}$) with trifluoroacetic acid (TFA) in $\ce{CH2Cl2}$ but i get minimum product and too much ...
4k views

### Why is hydrochloric acid often sold as 33% concentration?

What is the historical perspective for the choice of 33% concentration that is often found in commercial sales of Hydrochloric acid? Is this the same reason we find sulfuric acid sold at 37% and ...
873 views

### How is combustion speed regulated in solid propellants?

My question on Space.SE didn't yield anything I didn't know already: the secondary regulation mechanism – grain (cross-section shape) of the propellant, changing the area of open surface of the ...
22k views

### Dissociation of HCl in aqueous solution

My question is regarding $\ce{HCl}$. In my book it states that: $$\ce{HCl (aq) -> H+ (aq) + Cl- (aq)}$$ I understand that when added to water the $\ce{H}$ leaves its electron to the $\ce{Cl}$ ...
90 views

### Coconut oil vs Olive oil: Spray dynamics

Ps: If this would better fit Physics then please move it there or let me know. I put it here based on fact that viscosity and colloids were part of chemistry curriculum 10/15 yrs back in school. Let'...
251 views

### Base Peak Intensity different than higher value in Mass Intensity Map

I've been working with mass spectrum data analysis (but my field is computer science). I'm using a library that allows me to get the entire Mass Intensity of the MS1 scan (such as [time, intensity])....
166 views

### Can I split water without constant refill of solution?

I've looked all over the place to find a way for me to separate water without needing to put in salt. What I've found is you can separate water into hydrogen and oxygen through electrolysis (which ...
9k views

### Molecular Structure of Caffeine

I'm currently looking at a problem that asks about the structural relationship between the 4 nitrogens the caffeine molecule. I am asked to identify whether they are in perpendicular planar, coplanar, ...
31 views

### On what basis are certain elements selected for doping silicon?

I read online that transistors are made by doping silicon with other elements such as arsenic, phosphorus, or aluminium in order to increase its conductivity. How are these doping materials selected?
350 views

### Orbital definition [duplicate]

In some sources, including my textbook it is cited that an atomic orbital is the 3 dimensional region where the probability of finding an electron is 90-95% . But, Other sources such as Wikipedia ...
983 views

### What is the meaning of 'anion water' in coordination chemistry?

In Mechanisms of Inorganic Reactions by Fred Basolo and Ralph G. Pearson, a passage discusses the history of coordination chemistry. Ammoniates had been assumed to be analogous to hydrates. They ...
61k views

### How to determine whether a given compound is paramagnetic or diamagnetic? [closed]

Well i am very confused whether we can determine the magnetic property of compounds.. If it us asked for elements we can say by looking at electronic configuration... For ex- how is N2O diamagnetic?...
1k views

### What makes alcohol a good conservation product?

A common way of preserving food and organisms is immersion in alcohol. But what causes alcohol to preserve these items well?
42 views

### Products which adhere to human nail while still being removable/reusable?

I am at loss as to what I can use for my project. I require a product which can adhere to the human nail (not any damaging glues) while still being easily removable. There will be a degree of 'overlay'...
101 views

### detection of psilocybin with ehrlichs-reagenz

I tried to form the product of the detection reaction, however i dont know which product is correct or both products are wrong!
1k views

### Can Henderson-Hasselbalch equation be used to determine the pH of a solution when a strong base and a strong salt of that base stay together?

The following problem I have stated was not given to me as a homework. I have found this one in my textbook. I have solved it in my own way, but I'm not sure about the correctness of my procedure. I ...
2k views

### What does "dye content 80%" mean on Sigma Aldrich's product page for "Allura Red AC" (aka Red 40)

Here's a link to the page: http://www.sigmaaldrich.com/catalog/product/sial/458848?lang=en&region=US Why does it say "dye content 80%"? Shouldn't it be pure if it's a packaged powder? Is it 20%...
4k views

### Is glass an amorphous solid or supercooled liquid?

I have been informed that glass is a super-cooled liquid and is also considered to be an amorphous solid. Can it be both and, if not, what category does it fall into?
100 views

### Can sunlight and its heat create a caustic or toxic substance from coconut oil on human skin? [closed]

I heard that story quite often, if it's true, how does it work? Notice that I’m not talking about using coconut oil as a sunscreen (it’s another topic) but about the action of the sun on the oil and ...
384 views

### Work and entropy

I am not able to conceive why work wouldn't increase the entropy of a system. If i am compressing a ideal gas adiabatically and reversibly, the gas pressure inside would increase,meaning more no of ...
859 views

### Why do Bence-Jones proteins behave differently in urine heat test?

The preliminary test for proteinuria (proteins in urine) is precipitation/turbidity on heat due to denaturation. This turbidity should not disappear when 10% acetic acid is added - to differentiate ...
6k views

### What is the hybridisation of hydrogen in methane? [duplicate]

I am trying to understand hybridisation. In methane carbon has $\mathrm{sp^3}$ hybridisation, but what is the hybridisation of hydrogen? Is it $\mathrm{sp^3}$? If yes then why?
44 views

### Physical reason for the ideal lattice approximation

Why can we approximate a lattice as being infinite when we describe it as an ideal crystal? Is there any physical reason or is it just because the number of ions (/atoms) is so huge that we can treat ...
2k views

### How to prevent dripping when using a Pasteur pipette with solvents like diethyl ether?

I'm trying to use a Pasteur pipette for pipetting diethyl ether and regardless of the angle I hold the pipette at, the diethyl ether will automatically start dispensing itself (I am unsure of what ...
1k views

### Why the intensity vs. frequency graph initially increases for black-body radiation?

Max Planck had said that $E = n h \nu$ in his quantum theory. Then according to it, as the frequency of the light emitted increases, so the light's intensity should decrease. But it is not in the ...
2k views

### How to breakdown wax, preferably beeswax [closed]

I have a project that I'm working on at the moment, but I'm stuck on this detail. I'd like to find out what can I supplement beeswax with that is organic, non toxic, and safe if accidentally consumed, ...
56 views

### Reaction control on molecular level

Imagine I have a bottle with a random quantity of molecular hydrogen, and can apply exactly enough energy to break only one molecule of hydrogen. Is the reaction going to occur or the energy would be ...
234 views

### What makes DNA/Protein in a gel run in straight lines?

In a gel electrophoresis, let's assume an SDS-PAGE, I understand that the sample is loaded on a cuboidal well and the electric field is straight downward. It is easy to assume that the sample is going ...
2k views

### Gel electrophoresis separates proteins on the basis of what property?

In SDS-PAGE for separation of proteins, SDS is an ionic detergent that coats the unfolded protein to mask its native charge and give at a uniform charge to length ratio. Since the length of the ...
4k views

### Diffusion-controlled reactions, activation-controlled reactions and rate equation

I am confused as to where the rate equation can be applied and where not to be applied. https://en.wikipedia.org/wiki/Rate_equation In diffusion-controlled reactions from what I understand reaction ...
1k views

### Reactivity Towards Electrophilic Substitution [duplicate]

How do you decided which compound is the most or less reactive towards electrophilic substitution? For example, if the compounds are benzene, ethyl benzene, 2-phenylpropane and 2-methyl-2-...
4k views

### Sulfuric acid from elemental sulfur and hydrogen peroxide

Will this reaction proceed under standard conditions? I don't really care if it is quite slow, as long as it takes less than a month to finish: \ce{S8(s) + 24 H2O2(aq) -> 8 H2SO4(aq) + 16 H2O(l)}...
2k views

### Does dissociation happen in gases?

I understand that dissociation is when something dissolve. I heard this mostly only happen in liquids. But now I heard it can also happen in gases. Is this true? If so, when and why does this happen, ...
61 views

### Does 12 amu really equal the mass of one carbon-12 atom? [duplicate]

As I was studying chemistry, I encountered atomic mass units (amu) and based on some calculations, I realized that some numbers don't work out. Apparently, 12 amu is the mass of a single carbon-12 ...
21k views

### Acidic Strength of Nitrobenzoic Acid

The Correct acidic strength of the following : But according to me pK value of 2-nitro benzoic acid should be more than 4-nitro benzoic acid because NO2 might have H-bonding with COOH as NO2 have it ...
777 views

### Can a more electropositive metal replaced by a less electropositive one?

I read from this reference that rubidium is extracted by reduction of its chloride with calcium or sodium. How is it possible?. Their electronegativities are much higher than rubidium. I think ...