# All Questions

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### Are words on my T-shirt removable? [closed]

I wonder if the words on my T-shirt are removable? If yes, what kind of (chemical or physical) ways are there? They look like paints on the cloth, as the letter "C" has become blurred in the way ...
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### Product/(s) of the following reaction

I was wondering what the product will be in the following reaction: $$\ce{H3COOCH3 ->[\ce{H+}]} \:?$$ I was thinking about $\ce{CH3COOH}$ being a product but I do not know the mechanism.
6k views

### Reaction between potassium permanganate, alum, and sodium hydrogen sulfite

When I was a teenager, I played with a chemistry set. I tried adding potassium permanganate, alum, and sodium hydrogen sulphite (not sodium hydrogen sulphate) to water. Upon adding the third ...
105 views

### Methods: Does failing at intermolecular properties mean the same for intramolecular properties?

Let us consider the following: 1.) Method X fails at describing intermolecular non-covalent interactions. 2.) Method X excels at describing molecules of type Y. 3.) Method X ___?___ at describing ...
174 views

### Why would the loss of H₂ to space mean that the Earth's geochemistry would be based on acid/base reactions?

I am reading a paper[1] that contains the line: Most of the $\ce{H2}$ in the Earth's mantle escaped to space early in the Earth's history; consequently, the overwhelming majority of the abiotic ...
38k views

### Oxidation number for nitrogen in ammonium sulfate [duplicate]

I'm trying to find the oxidation number of $\ce N$ in $\ce{(NH4)2SO4}$. The answer is supposed to be $-3$ but I can't figure out the logic behind this.
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### What is 'autogenous pressure'?

Compound 1 was hydrothermally synthesized under autogenous pressure[1] I've seen this term used a few times, but with no real explanation of what it means forthcoming. I suspect it refers to the ...
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### What is the chemical structure / hybridization of sulfuric acid?

I was looking at the chemical structure of $\ce{H2SO4}$. Intuitively, I would have expected this molecule to be square planar in accordance with $p^2d^2$ or $sp^2d$ hybridization, but instead it is ...
2k views

### Why does cesium have a positive electron affinity?

When an electron is added to cesium, why is energy released?
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### Modeling perturbations of a quantum mechanical system

I'm wondering how to properly perturb a quantum mechanical system. I'm looking for a way to express the return to equilibrium of such a perturbed state, where the perturbation is in the Hamiltonian. ...
1k views

### Very slow chemical clock reaction

I'd like to preface this with a declaration of my understanding that this is not necessarily possible. I was wondering if anyone knew of a chemical clock reaction where the period before the first ...
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### Modern alternatives to Gaussian [closed]

Specifically, I'm curious if there are any programs which come close to Gaussian in breadth but also take advantage of things such as GPU processing. There's a page on wikipedia that goes through ...
298 views

### Spectral analysis of periodic table of elements in time domain

I'm trying to get the spectral analysis data of the periodic table of elements in the time domain format or find a site that has the data in the time domain format. All the sites I know have the data ...
2k views

### Is there a simple way to get the circular dichroism of a molecule from its structure?

Are there any heuristics to get the relative absorbtion of left and right circularly polarized light by a molecule from its molecular structure? Is it even possible to predict which polarization is ...
106 views

### What legal guidelines exist for completeness of a Materials Safety Data Sheet?

I know that the answer to this question will vary by country, but some aspects must be similar amongst those countries that have authorities overseeing chemical and industrial hygiene. The Wikipedia ...
11k views

### Can acidic conditions break disulfide bonds

I am denaturing a protein using organic solvent and acid (49:49:2% water:methanol:acetic acid), but I want to maintain the disulfide bonds. My chemistry knowledge isn't good but disulfides are broken ...
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### Why don't atoms with expanded valence shells have a formal charge?

I'm working through Chemistry - Principles and Practice, 3rd Edition and I have few complaints so I don't think it's the text. At one point, I was asked to draw the Lewis structure, with formal charge,...
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### How to properly dispose of sodium…or store it properly

While performing an inventory of my school's chemical storage closet today, my fellow teacher and I found some sodium tucked away in the back corner of our flammables cabinet. One container appears ...
3k views

### Which of the following possesses the highest energy electron?

Which of the following possesses the highest energy electron? $\ce{Br-}$ $\ce{Ca^2+}$ $\ce{Cr+}$ $\ce{As}$ Don't bromine and arsenic have equally high energy electrons (i.e. in ...
571 views

### What does the reaction of chromium with ozone form?

I know almost nothing beyond 10th grade chemistry. I'm trying to name a web application, and was wondering what the products are of a reaction between the element Chromium and the gas Ozone (...
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### How can I identify and neutralize the chemical leaching out of new nitrile gloves?

I have a few cases of brand-new, nitrile gloves of a type and vendor that used to be good. But apparently, the vendor has moved manufacturing to a different country and outsourced customer service to ...
5k views

### Interpreting a formula tattoo

I saw on the Internet and I'm curious as to what compound is represented by it.
2k views

### Does the chemical in an alkaline battery make battery leaks unavoidable?

Battery leaks was an issue in the 80s and 90s, and since quality and innovation is constantly improving, I thought battery leak might be slowly going away. But I found that even nowadays, name brand ...
331 views

### Is there a liquid crystal or similar material that gets cloudy when an electric field is applied, but is otherwise clear?

Is there a way to make a liquid, such as a liquid crystal material, transition from cloudy or clear and vice-versa using only electric current? By cloudy, I mean, similar to the effect that ...
489 views

### standard reference for thermodynamic properties?

I'm a non-chemist attempting to put together a chemistry paper. Up to now I've got my thermodynamic data from various random pdf files found on the web, together with Wikipedia. Now that the paper is ...
409 views

### Products of HMTD decomposition

Hexamethylene triperoxide diamine, "Hex" for short, is an explosive organic compound. I want to know the products of this reaction: $$\ce{C_6H_{12}N_2O_6 -> ? + Energy}$$
13k views

### Pipetting strong acid with plastic material

Can I pipette concentrated sulfuric acid using a plastic pipette tip? Will either the plastic or the acid be affected?
5k views

### Why is methane's molecular formula conventionally “CH₄”, while water is “H₂O” (among others)?

While revisiting some of my old notes about the Miller-Urey experiment, I stumbled across the "equation"... Electricity + $\ce{CH4~/~ NH3~/~H2O~/~CO}$ = Amino Acids This got me thinking. ...
1k views

### Comparison of acids to dissolve phosphates

I am currently reading this German paper on the dissolution of phosphates by acids and chelants. The authors do a "fast-test" of the dissolving power of different acids which goes as follows:...
6k views

### Polymer Slurry used in boring foundation holes?

I watched a video on the construction of Burj Khalifa, Dubai. The construction engineers answered that they're using a special type of protection known as Cathodic protection to protect from the ...
783 views

### How to compute the residence time for given flow rate in standard cubic meters?

I'm given a flow rate of a gas mixture of $3\ \mathrm{Nm^3/h}$ in standard cubic meters through a cylinder of length $50\ \mathrm{cm}$ and cross section $70\ \mathrm{cm^2}$, can I compute how long a ...
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### What chemicals could absorb/adsorb ambient atmospheric methane?

From an article in the New Scientist in 2010, Since pre-industrial times, methane levels in the atmosphere have risen from around 715 parts per billion to nearly 1800 ppb, claims Folberth. "If ...
2k views

### Good acid for cleaning marine toilets

Problem: On my boat I have a marine toilet. It is operated with salt water. The problem is, on the interior of the outflow tubing it accumulates some sort of hard grime. I am looking for a good way to ...
5k views

### Bisulfate vs Hydrogen sulfate

What's the difference between bisulfate and "something" hydrogen sulfate? Has there historically been a preference for one over the other?
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### Iron nomenclature differences between Iron(III) and Ferric [closed]

As I was doing my Ap Chem homework, sometimes the question would use Iron(III) and sometimes it would use Ferric. What's the difference in usage? Also, what's the difference between Iron(II) and ...
2k views

### How to determine stable electron states in ionic and covalent bonds?

I'm working on a program that needs to determine if a bond between two or more elements will result in a stable state. I understand at a high-level how to fill electron subshells using the Aufbau ...
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### Order of dipole moments

What is the order of dipole moments for $\ce{SO3, SiO2, P2O5,}$ and $\ce{Cl2O7}$? This question is from a book and the answer given is $\ce{Cl2O7 < SO3 < P2O5 < SiO2}$. Can someone explain ...
How can $\ce{CO2}$ be converted into carbon and oxygen? $$\ce{CO2 -> C + O2}$$ Alternatively: $$\ce{CO2 + ? -> C + O2}$$ I'm aware that plants are capable of transforming $\ce{CO2 + H2O}$ to ...