Questions tagged [physical-chemistry]

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

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201 views

What happens if Jupiter is ignited?

I was wondering, what would happen if there was a large amount of oxygen released into Jupiter's atmosphere, than igniting it? Because Jupiter is 90% gas, therefore being a big fire waiting to happen (...
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1answer
48 views

Why do the sun and planets differ in their chemical elements composition?

The chemical elements composition of the sun changes as its nuclear furnace changes elements into heavier ones. But it is supposed to be mostly Hydrogen at the start. The planets are too cold for ...
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2answers
593 views

Implications of parity violation for molecular biology

In biology, the concept of parity emerges in the context of chiral molecules, where two molecules exist with the same structure but opposite parity. Interestingly, one enantiomer often strongly ...
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1answer
48 views

Will a solution undissolve if left for a long time? [duplicate]

Simple questions: In a solution of NaCl (aq) that is unsaturated, will the Na and Cl ions eventually start collecting in the bottom of the container because of gravity pulling them down? OR Will ...
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2answers
73 views

Is it possible to break a carbon dioxide molecule using electromagnetic waves?

I'm no expert in physics, but I was just wondering if breaking apart $\rm CO_2$ into oxygen and carbon would be possible using certain electromagnetic wave?
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43 views

When we mix water with H$_2$SiF$_6$ and boil them, how much of the H$_2$SiF$_6$ evaporates?

If water evaporates also at temperatures much lower then its boiling point, and so do, I believe, other liquids, how much H$_2$SiF$_6$ (boiling temp. 108 C) is to be found in the steam over boiling ...
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1answer
30 views

Seperating Charges in a Cell

Sorry for not being detailed for my question here but how do charges seperate in a cell and when the electrons are pumped out of the battery does it return and become positive ? Yet again sorry if I ...
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1answer
73 views

Are there other properties besides lower boiling point that make isobutane a better refrigerant than butane?

Asked differently, if -1C is low enough for the application is there any reason not to use butane rather than isobutane as the working fluid in a refrigeration system?
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1answer
80 views

Would a very strong force of gravity make things break apart?

If I take an hammer and slam it on a table, I will not be surprised to see the table breaking and my anger slowly vanishing. I remember a difference being made between impact and non-impact forces ...
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1answer
23 views

Multi-stability potential is suitable for interdisciplinary branches of science?

The potential function $V(x) = c(x-a)^2(x-b)^2$ with constants $a,b,c$ and some variable $x$ has two minima: One at $x=a$ and another at $x=b$. When plugging this potential function in Newton's ...
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53 views

Why applying a force to something does not always result in an energy consumption? [duplicate]

I usually don't envy a simple table, but I'm a little bit concerned with why it isn't apprently wasting any energy while doing some "useful things". I'm not a physicist and I can't find an example ...
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2answers
162 views

Is the rate of evaporation in the below mentioned situation constant when liquid vapour equilibrium is not reached?

i am studying liquid vapour equilibrium and there is the set up (below) for the experiment.The conditions:temperature is constant throughout. in this case is the rate of evaporation of the liquid ...
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1answer
84 views

Spring potential energy transformation [duplicate]

Suppose I take a metal spring and compress it, and in its compressed state I dip it in a strong acid solution. When the acid reacts with the metal it reacts to form a salt of the metal. Where does the ...
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0answers
42 views

What is the narrowest possible functioning straw that could be made?

Let's assume that the straw/pipe/tube can be made of any material, but it should be at least 100 times as long as the inside is wide. How narrow could the inside of the straw be made before it is no ...
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0answers
51 views

How does my lab's Helium-filled cathode ray tube produce a blue-ish glow? [duplicate]

In my university's lab, we have typical "e/m apparatus"'s, i.e. a cathode ray tube nested between a Helmholtz coil. Here is the manual for the device we are using. When operating the device, we ...
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1answer
54 views

How do self-developing holographic plates work?

Litiholo started working on self-developing plates in mid-2004 and managed to achieve its goal and started selling these no-fuss self-developing hologram kits that produce pretty good results. ...
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27 views

Will a brief current generate if I connect with a conducting wire two pieces of elements with a large electronegativity difference?

I'm studying how voltaic cells behave and how batteries were invented. I read this article on the scientific american, and it explains that if you connect a piece of zinc with a piece of copper ...
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1answer
207 views

How to calculate rocket Burn Rate?

I’m trying to calculate the burn rate of a theoretical sugar rocket (for a computer game). The equation I have is $r = aP^n$ . Where $r$ is the burn rate, $a$ is the burn rate coefficient, $n$ is the ...
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1answer
93 views

magnetic and electric interactions in atomic level

From what I understand Van der Waals (VDW) forces are the primary source of inter-molecular interaction. There are three different possible origins for van der Waals forces: permanent dipole-permanent ...
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1answer
91 views

Why doesn't optical rotation dispersion spectrally overlap with circular dichroism?

From my understanding of Kramer's Kronig relations applied to chirality: optical rotation dispersion should be correlated to circular dichroism. Why is it then that many molecules have an optical ...
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1answer
185 views

Can a plasma ball light up minerals that fluoresce?

I want to know if I could use a plasma ball to light up a UV poster that are typically activated by blacklights. option 1: using light from the globe According to my research it seems that the light ...
12
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1answer
204 views

Why do cold chocolate bars crack randomly outside the crevasses when twisted?

Why is it that an ordinary chocolate bar (e.g. 4 x 12 pieces) breaks easily where it is supposed to when the chocolate bar is at room temperature or higher but breaks "randomly" when the chocolate is ...
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4answers
1k views

Is water really $H_2O$? On a comment concerning the quantum mechanical description of water made by Hilary Putnam [closed]

I wanted to pose a question here (also posted to r/physics a bit earlier) and was hoping the you all might be able to help. I was re-reading a book by the philosopher Hilary Putnam titled Naturalism, ...
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2answers
48 views

Why do we need to add proton and neutron as same number to figure out the weight of it?

For example, the Carbon is number 6. That means it has 6 protons. If we add the 6 neutron the total is 12 and we call it carbon 12. 1 neutron and 1 proton equal as the 1 atomic mass unit. That means ...
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1answer
50 views

Why don't enzymes care about the direction of a reaction?

In Richard Feynman's lecture, he says, "In enzyme you see, does not care in which direction the reaction goes, for if it did it would violate one of the laws of physics." I don't really understand ...
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3answers
234 views

Electron spin and chemical properties

I just learned about spin in class and I recall my professor vaguely mentioning how the spin of an electron is what determines certain chemical properties. I have trouble seeing why. Suppose an ...
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0answers
54 views

Binding energy $\rm^{212}Pb$-$\rm^{212}Bi$ and $\rm^{228}Ra$-$\rm^{228}Ac$

I'm considering the radioactive series of thorium-232. I do not understand the following fact: How is it possible that the binding energy decrease in the cases highlighted in red? In fact in both ...
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0answers
99 views

Are nucleons, atoms and molecules identical particles?

Why are nucleons, atoms and molecules considered identical particles (bosons or fermions) even if they can be distinguished by the state of their most elementary components? Also, what size does a ...
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1answer
42 views

Thermodynamic process with a decrease in entropy [duplicate]

I've done some searching on google and wikipedia, but I can't seem to find anything. What is the quasi static process on an ideal monatomic gas where there is a decrease in entropy? Thanks
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3answers
414 views

Meaning of the term “phase” in chemistry and thermodynamics

I have some doubts about the definition of the term “phase” in chemistry and thermodynamics (is the meaning the same?). The "textbook" definition is: "A phase is a form of matter that is uniform ...
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1answer
123 views

Physics for understanding Chemistry [duplicate]

I am a highschooler who eventually wants to deeply understand the properties of elements and compounds etc. I have been dabbling in some Chemistry books lately but I find them a bit superficial, and ...
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2answers
874 views

Conservation of energy when we drive a car

When we drive a car, we use gasoline as the source of energy. When we arrive at the destination, we lose some of the gasoline, used to move the car from one point to another. Then how energy is ...
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2answers
141 views

Is there any non-metallic oxide that remains in solid state at room temperature?

Except for metallic and semimetallic oxides, is there any oxide (non-metallic oxide) which remains in the solid state at room temperature?
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2answers
956 views

Why do we need to sprinkle water on cotton clothes before ironing/pressing them? [closed]

Many a times, cotton garments need water to be sprinkled upon them before pressing or ironing. Without water, these clothes cannot be properly pressed by a hot iron. Steam iron can be used as an ...
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0answers
52 views

How long does it take to fill a $100\ \mathrm{m^2}$ room with new air? [closed]

How long does it take to fill a $100\ \mathrm{m^2}$ room with new air. For example. If the room is $100\ \mathrm{m^2}$ room. The window is $1\ \mathrm{m^2}$ and is left open. How long would it take ...
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0answers
18 views

What would happen if you were able to shoot a oxygen plasma bead?

I was curious about the effects a bead of superheated oxygen (to the point of a plasma state) would have not the air and nearby spectators. It is my understanding that the temperature required to ...
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1answer
1k views

Does adding salt to water decrease the latent heat of vaporization?

Suppose we have a material such as salt that when added to water it will increase its boiling temperature. Can we conclude that it also has to reduce the latent heat of vaporization? I'm asking this ...
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1answer
144 views

What are sigma and pi bonds in physics language?

Chemists often discuss sigma and pi bonds. To a physicist, it's not easy to figure out what these actually are, as discussions tend to be full of lots of chemistry jargon about "antibonding", "...
2
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1answer
50 views

Collisions of atoms in a gas and decoherence of wavefunctions [duplicate]

Do the collisions of atoms in a gas have the effect of reducing the number of electrons whose wavefunctions are in superposition states? The idea is that these collisions are effectively interactions ...
43
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1answer
6k views

Why doesn't soda go flat immediately after opening?

So, soda is under pressure and has gas dissolved in it. But, when you open it, the gas is still dissolved in it. But, if we wait a few hours, the gas has escaped into the atmosphere. What factors ...
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1answer
54 views

Meaning of extraction ratio $E=\frac{C_{Ai}-C_{Ao}}{C_{Ai}-C_{Bi}}$

My goal is to understand the meaning of the extraction ratio (artificial kidney, not other systems). I have the system in figure ($Q$ volumetric flow, $C$ concentration, the red line is a permeable ...
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1answer
121 views

Four fundamental forces to explain metabolism

Apologies if this question does not make sense. I have tried looking for an answer but couldn't find one and have zero knowledge I was watching this video last night which I found fascinating. In it,...
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1answer
64 views

Do discrete symmetries in molecules leave statistical “artifacts” like the Equipartition Theorem?

In statistical mechanics we have the equipartition theorem which can derive heat capacity simply from degrees of freedom. For example, diatomic gases have an increase heat capacity of $ \frac{7}{2} N ...
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90 views

Conditions on Quantum Numbers in Pseudo Harmonic Oscillator or Mie type potential

I have been trying to solve the problem of 3D Schrodinger equation with the following potential. $$ V(r)= a_{0}+\frac{a_{1}}{r^{2}}+a_{3}r^{2}. $$ I got the following energy eigenvalues with quantum ...
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1answer
46 views

What happens when you breathe on glasses and look at white light?

Something interesting happens when I breathe on glasses and look directly at a source of white light: I see a circle-like spectrum of some colors (which kind of look like infrared visuals, sorry if I ...
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2answers
100 views

How does the lowered surface tension of soapy water make it better for cleaning?

I've read a few other answers on similar questions that talk about the lower contact angle and lower surface tension with soapy water (compared to tap water), but nobody seems to mention how this ...
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1answer
371 views

What generates most heat in a rifle barrel, burning gunpowder or friction?

As anyone who's done some shooting quickly finds out, it does not take very many rounds to heat up a barrel to be too hot to touch. A lot of folks think the 'burning of the propellant, and its ...
2
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2answers
95 views

Extreme life - energy source for living tens of kilometers underground? [closed]

Living cells were found up to at least 12 miles underground (article), and in other extreme places (BBC survey article), for which beside the problem of just surviving in such extreme conditions, a ...
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1answer
87 views

Why are atoms so different from one an another? [duplicate]

An atom is composed of a positively charge nucleus, with a cloud of electron(s) around it. But I can seem to understand the huge differences between 2 components that seem so close in terms of what ...
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1answer
80 views

Complexity of Ab Initio quantum computation of bulk properties [closed]

Background I'm an undergrad studying Computer Engineering, however I switched from ChemE. I just completed Physics 2, however I've a cursory understanding of higher level Physics concepts (Hamilton ...