Study of macroscopic and microscopic phenomena in chemical systems in terms of physical laws and concepts [thermodynamics, statistical mechanics, kinetic theory, quantum mechanics...].

learn more… | top users | synonyms (2)

1
vote
2answers
34 views

Notation in a neutron star superfluidity

In this article "Neutron Star and Superfluidity", by Ka Wai Lou: http://guava.physics.uiuc.edu/~nigel/courses/569/Essays_Fall2010/Files/lo.pdf symbols as $^1S_0$ and $^3 P_2$ are shown, but I not sure ...
0
votes
1answer
29 views

Why higher FAT level implies more signal in XPS analysis?

In XPS analysis, the FAT (Fixed Analyzer Transmission) parameter controls the electrostatic field of an emispheric analyzer, called Pass Energy $E_P$. The FWHM of a peak of signal is given by ...
2
votes
1answer
111 views

Spacetime curvature effect on chemistry

Do current chemistry / astrophysics / stellar chemistry calculations include the effects of the curvature of spacetime on chemical reactions? For example, the heat transfer from a point closer to the ...
1
vote
2answers
192 views

The NERVA had to use liquid H2… But why?

The NERVA engine, developed at the late 60ies, was a nuclear thermal rocket developed for vacuum use in space craft. It was supposed to use Liquid Hydrogen, a cryogenic fuel with quite a few issues ...
1
vote
1answer
34 views

Spin-$\frac{1}{2}$ particles in chemistry

Electrons and protons are spin-$\frac{1}{2}$ particles, so under a rotation by 360$^\circ$, their wavefunction changes by a sign. They are also commonly found alone in chemical reactions, especially ...
0
votes
0answers
28 views

Bonding Two Cationic Hydrogen Isotopes (protium) yields H2 or He?

If you have two hydrogen atoms. And they are the isotope form "Protium" (1 neutron removed) and they are also cationized +1 (1 electron removed) then you have (in a sense) a single proton (two of them ...
1
vote
1answer
36 views

What is the relation between Nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR)? [duplicate]

It seems to me that the basic principles are exactly the same, right? Then I am puzzled that the former was awarded a nobel prize while the later not. I noticed a similar question here What's the ...
-2
votes
1answer
139 views

Parkhomov's E-cat reproduction [closed]

In the beginning of the year, Professor Alexander Parkhomov of Lomonosov Moscow State University claimed to have replicated (as read in e.g. Wired) of the E-cat functioning, albeit with lower effect. ...
2
votes
1answer
945 views

How does wax fuel a flame? [duplicate]

I get how an oil lamp runs until the fuel runs out, but a normal wax candle doesn't seem like it works the same way.
0
votes
3answers
119 views

Is there an way water can burn or cause fire?

Water known as the fire extinguisher.What is the possibility watere being the fuel to fire. "Pure water"
0
votes
1answer
24 views

Ionization Through Atomic Collisions - Any Reason(s) for Its being Unimportant?

The dominant processes which contribute to the ionisation of a gas (which is possibly hot and dense) are often deemed to be electron-impact ionization ($A + e^- \rightarrow A^+ + e^- + e^-$) and ...
1
vote
1answer
60 views

Why is blue darker than yellow in an analog black and white photograph?

Blue is perceived darker than yellow by the human eye, because of biological principles within the eye. I can understand that therefore, when making a picture black&white in software like Adobe ...
0
votes
1answer
47 views

electron shell jumping in Iron?

I understand a "little" about electron shell jumping, I was wondering about "Iron", If iron was heated to a gas, perhaps held in a vacuum maybe even under pressure, would the added energy make the ...
5
votes
3answers
332 views

Are chemical bonds matter?

So it recently blew my mind that chemical bonds have mass. And that a spring that's wound up similarly weights a little more. But there is a distinction between mass and matter. I believe that a ...
-2
votes
1answer
88 views

Exothermic vs. endothermic reactions

An exothermic reaction is a chemical reaction that releases energy by light or heat. Does this mean that if I mix two chemicals in a test tube when the reaction between them is endothermic then the ...
0
votes
0answers
24 views

Charge Transport Mechanicsm of Organic Semiconductors

I understand the general concept behind inorganic semiconductors. Start with Silicon, dope the material to add an electron or a hole, and now these are free to move about in the material, creating ...
2
votes
2answers
191 views

Calculating the radius and potential energy of an atom?

Is there a general equation that gives the potential energy of any element at each energy level? I know that there is an equation for the potential energy of a hydrogen atom at each energy level but ...
0
votes
2answers
69 views

Does chemical energy contribute to mass? [duplicate]

Does chemical energy contribute to the mass of an object? I don't mean the bond energy, but the possible energy that could be released (i.e. Does an atom of oxygen and a molecule of hydrogen (H2) have ...
1
vote
1answer
41 views

How much carbon dioxide do we actually ingest from a can of coke?

On this most trustworthy page it states that a 355 mL can of coke contains on average about 2.2 grams of carbon dioxide. As far as I know, this carbon dioxide can exist in solution as carbonic acid, ...
1
vote
2answers
160 views

Is it possible to mix a luminescent drink? [closed]

Is it possible to create a drink that glows? In other words, is it possible to create a non-poisonous drink that fluoresces? Are there known compounds suitable for that? If not, then what about a ...
4
votes
1answer
66 views

What is the specific source(s) of sliding kinetic friction

In simplistic (K-8) physics classes, it seems to be generally instructed that the friction between two moving surfaces is due to the unevenness of each surface and the microscopic roughness. However, ...
0
votes
0answers
31 views

Difference between “chemical master equation” and “master equation”

Is there any mathematical difference between "master equations" and "chemical master equations"? Is the chemical master equation in any way more specific than the master equation? I see the former ...
0
votes
2answers
159 views

Gibbs free energy + maximum work

The Gibbs free energy is the maximum amount of non-expansion work that can be extracted from a closed system; this maximum can be attained only in a completely reversible process. This maximum work is ...
1
vote
2answers
73 views

Formation of bonds and heat release

We know when there's formation of bonds during chemical reaction there's heat release to the surrounding due to conservation of energy. But what I am confused about, is the kinetic energy of the ...
2
votes
2answers
59 views

Quenching of binary alloy: Concentration equilibrium

I'm currently reading "Models for phase separation and their mathematics" by Paul C. Fife and there is a paragraph which I don't understand because I lack the necessary background in ...
2
votes
1answer
69 views

Do antiparticles exhibit different chemical properties?

In my physics class today. My teacher mentioned anti-helium and since I had never heard of anti-atoms (if you get what I mean by that) just antiparticles, this made me think: If we could produce ...
3
votes
3answers
518 views

Jet turbine blades from single crystals, how are they formed?

I know about nothing about crystals, although I do know a bit more about jet turbine engines, and I definitely know that you don't want the fan blade hitting the fan housing. The reason given in the ...
0
votes
0answers
55 views

Difficulty in understanding Maxwell Boltzmann distribution in case on ions in a field

I learned that the velocity of molecules obey Maxwell Boltzmann (MB) distribution at a Temperature T. If I have ions of mass 'M' accelerated to 2eV in a specific region. As the ions are not ...
2
votes
0answers
47 views

The underlying chemical interactions behind torque

I did some searching around, and didn't find any previous topics that address torque in this specific way -- here goes: Say I just have a plain ol' piece of wood -- relatively long in one axis, so it ...
2
votes
0answers
85 views

Why is the activation energy of combustion so large compared with regular bonding?

I wanted to know why combustion requires an activation energy and I found this article (see this too). It says that molecular oxygen ground state is a triplet state (according to Hund's rules), and ...
3
votes
1answer
146 views

How to compute this change of Gibbs energy for a Van der Waals gas?

The change of Gibbs energy at constant temperature and species numbers, $\Delta G$, is given by an integral $\int_{p_1}^{p_2}V\,{\mathrm d}p$. For the ideal gas law $$p\,V=n\,RT,$$ this comes down to ...
1
vote
3answers
527 views

How does the dissolution of salt affect the solution density?

Suppose you have a container of water as a solvent and you a certain amount of salt as a solute sitting at the bottom of the container that has yet to start dissolving. Supposing temperature and ...
0
votes
0answers
20 views

Why does carbon help with electron transfer in a dye sensitized solar cell?

what property of carbon(soot) makes it easier for electron transfer within a dye sensitized solar cell?
0
votes
0answers
46 views

Visible wavelengths of air fluorescence data - needed for school demo laser telephone design

I'm seeking information about fluorescence in visible wavelengths (390-700nm) of any of the main constituents of air ( $ N_2, O_2, CO_2, H_2O, CO, etc. $) that can be excited with a (hopefully ...
0
votes
1answer
188 views

Is water steam in air a case of liquid in gas solution?

Thinking of this question, I thought that the phenomenon of water evaporation into the air is totally analogous to the solid (say, salt) that is dissolved into a liquid (water). Indeed, in this ...
1
vote
0answers
113 views

How does fluid velocity affect the dissolution of some solute in the fluid?

Suppose we have a perfect sphere of some solute such as sugar and we place it in a fluid such as water, at a certain temperature, that is not moving. It will dissolve and diffuse into the water due to ...
0
votes
1answer
45 views

Why don't fire hoops blow out while spinning, but blow out when blown out?

My friend spins fire hoops and we're wondering why they don't blow out while she's spinning them, but do, when she blows them out one by one. I don't imagine there's so much more CO2 (so much less ...
0
votes
0answers
44 views

Heat Retention of Wine

This may seem odd and lengthy but I am going to attempt to consolidate my thoughts as much as possible. I'm sorry in advance for the length of my post and if this is confusing. I am currently ...
5
votes
2answers
352 views

Extra vibrational mode in linear molecule

When calculating the number of vibrational modes for a molecule, the formulas differ for linear $(n = 3N - 5)$ and non-linear $(n = 3N - 6)$ molecules, where $n$ is number of modes and $N$ is number ...
1
vote
0answers
47 views

What factors are influencing a woosh rocket?

Not sure if this is too much chemistry, but I'll try: If I fill a plastic bottle with a small amount of rubbing alcohol, shake it around and hold a match to the bottle neck, I'll get a flame wooshing ...
0
votes
1answer
103 views

Energy of a system if the nuclear repulsion increases

I have calculated the optimised geometry for a molecule. I have noticed that the energy of the nuclear repulsion increases with each iteration of optimisation. What is the logic behind this?
0
votes
0answers
65 views

Virial equation - Taylor expansion

I don't get how Taylor expansion over $ \frac{1}{\overline{V}} $ of Virial equation of state is carried: $Z = \frac{P\overline{V}}{RT} $ which yields $$ Z = 1 + \frac{B_{2V}(T)}{\overline{V}} + ...
0
votes
0answers
26 views

Maxwell relations | U goes down pressure?

Differentiating Helmholtz function $ A = U - TS $ with respect to $V$ we get: $$ (\frac{\partial A}{\partial V})_{\scriptscriptstyle T} = (\frac{\partial U}{\partial V})_{\scriptscriptstyle T} ...
0
votes
2answers
97 views

Electrolysis boat engine

Would it be possible to create a submersible boat engine using the combined principles of electrolysis of water, ramjet propulsion, and hydrogen-oxygen combustion similar to that used in rocket ...
8
votes
1answer
2k views

How do candles and wicks work?

The wick of my tea candle was buried in wax. So I lit a piece of paper and stuck it in the wax. Now the wax is burning off the paper, as if that were the wick. The wax itself wouldn't light on ...
0
votes
0answers
50 views

Does a fixed amount of gas have slighty more mass when at a higher temperature?

According to relativity, energy and mass are equivalent. Does this mean that the energy added to a fixed amount of gas when it is heated adds slightly to the mass of the gas? The difference would be ...
0
votes
0answers
44 views

Filling an empty box with ambient air

A rigid box has a volume of $V_1$ and is thermally isolated so that it exchanges no heat with its environment. Initially the box is empty, and the air around it has a pressure of $P_0$ and a ...
0
votes
2answers
46 views

Molecules from atoms [closed]

Why does two oxygen atoms combine to form a molecule and not 3 or 4?Also why does one sodium and one chlorine atom combine to form NaCl while two chlorine atoms are required to combine with one ...
0
votes
2answers
701 views

Correlation energy - is it the difference between the Hartree-Fock energy and exact energy, or Hartree-Fock PE and exact PE?

For some reason I can't find anything stating it either way explicitly. What I'm talking about is this. Is this difference referring to potential energies or just energies in general? I assume it's ...
0
votes
1answer
70 views

Why water expands when freezes? [duplicate]

I'm sure this is for most of you a basic question, but it really puzzles me: How it is that, even though all materials expand as they get warmer, and contract (maybe these are not the correct terms) ...