Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or compound molecules made from a variety of atoms (e.g. carbon dioxide). A gas mixture, such as air, contains a variety of pure gases. What distinguishes a gas from liquids and solids is the vast separation of the individual gas particles. This separation usually makes a colorless gas invisible to the human observer. The interaction of gas particles in the presence of electric and gravitational fields are considered negligible, as indicated by the constant velocity vectors in the image.
The gaseous state of matter occurs between the liquid and plasma states, the latter of which provides the upper temperature boundary for gases. Bounding the lower end of the temperature scale lie degenerative quantum gases which are gaining increasing attention.
High-density atomic gases super-cooled to very low temperatures are classified by their statistical behavior as either Bose gases or Fermi gases. For a comprehensive listing of these exotic states of matter see list of states of matter.
For a freely expanding ideal gas(irreversible transformation), the change in entropy is the same as in a reversible transformation with the same initial and final states. I don't quite understand why this is true, since Clausius' theorm only has this corrolary when the two transformations are...
I was thinking the other day about green houses and how they would act in space or on another planet without an atmosphere. I know that green houses work on Earth by stopping convection but could they theoretically trap heat in a non atmospheric environment? I am imagining a material that allows...
Hello, I just learned about the binding capacity of Hemoglobin (Hb) and that it is proportional to the partial pressure of O2 in the blood here is the curve :
it does have a sigmoidal shape, but here is the problem: in the lecture, it's said that Hb has an increasing affinity to O2 the more...
The general balance equation is as follow: d[m{u+gz+v2/2)sys=(u+gz+v2/2)dmin-(u+gz+v2/2)dmout +dq+dw.
I understand that I would take in consideration the cross sectional area as well as the mass flow rate. However I can't figure out what else to consider as if atm pressure should be considered...
For the first calculation of the velocity of the gas I use the first equation and this converted in meter would be look like this (first value as an example)
v=299792458 m/s * (6.76813x10^-7-6.768x10^-7)/6.768x10^-7 =5836.03m/s or 0.0019c
this was the velocity of the gas for the first spectral...
Hi,
I've been thinking about the solution for cleaning a water-cooled gas cooler and would love to hear some advice from the smarter people with more experience.
Description - I will try to roughly explain the concept.
Gas Cooler is used to decrease exhaust gas temperature. The exhaust gas...
With a real inert gas (i.e. nitrogen N2) being compressed in a piston-like configuration, I'd like to estimate the peak pressure and peak temperature at the instant the gas is brought to full compression.
Initial pressure and initial temperature (in the uncompressed state) are known: typically...
Hey all. I'm trying to understand the evolution of the velocity distribution function of a gas undergoing free expansion. I know that at t=0, the velocity distribution function is given by ##u(t=0, x)=Ax^{1/2}##, where ##A## is a known constant.
From the momentum equation, I have:
##du/dt+u...
Hi,
I recently read the following article on BBC online: "Revealed: Huge gas flaring emissions never reported (https://www.bbc.co.uk/news/science-environment-62917498)". Can they not use the ‘waste’ gas from flaring to generate electricity? Is it not feasible or economically viable? Do they...
Is it possible to weight a gas in a container surrounded by a vacum? I am arguing with flat-earthers on how gas weight is determined.
I just assumed that you can weigh a gas by placing it in a container on a scale inside a vacum. I think this was wrong. Can you do this or must you weight gas...
I apologize. I didn't see any general chemistry categories, so I am posting my question here.
Microbes and methane are inextricable from one another. My question is this. Are microbes "encased" in gases like methane when they rise into the atmosphere? Surely microbes can become particulate...
I can’t quite work my head around this question, I am having a difficult time analyzing the question, I can’t seem to make out what the initial and final conditions are
would appreciate all the help I could get cheers
(The equation of ideal gas is PV=NRT.if P=1atm,N=1mole,T=0°K,R=gas constant then volume = zero. Hence, the volume of an individual molecule of ideal gas is zero)
An individual molecule of ideal gas is assumed to have zero volume. The molecules of ideal gas are assumed to be dimensionless points...
It takes energy to compress an ideal gas, and that same amount of energy is output as heat. But we also gain the potential energy of the compressed gas. It seems to me that we are doubling up our energy.
Can anybody explain in simple, practical terms (to a humble mech engineer) how this works...
Hello,
I am currently working on a research project that involves filling a 10L tedlar bag with about* 8 liters of methane gas from a compressed gas cylinder. I'm trying to work out the best way to fill the bag with a reasonable degree of accuracy while also minimizing (or hopefully avoiding...
Every morning I boil two eggs for ten minutes. My gas canister emptied faster than I thought it would. Now I had noticed that most of the air heated by the gas never touches the pot. I had another burner with half the diameter of the one I had been using. That means 1/4 the circumference...
I have a vacuum chamber of volume V connected to a vacuum pump via a tube of radius R and length L, and I want to design this "tube" such that R can be controlled in order to provide a constant rate of pressure change inside of the chamber of 2.5 mbar/sec, from atmosphere down to ~0.5mbar...
The volume of the cylinder is ##V=\pi r^2 h=\frac{7\pi}{250}\ m^3## the number of moles is ##n=\frac{15}{16}\ mol## so from ##PV=nRT## we get ##P=\frac{nRT}{V}=25975.5\ Pa##.
Now, for the second question, it should be an isochoric process so ##V_2=V_1## and ##P_2=P_1+0.8P_1=\frac{9}{5}P_1## and...
Suppose there is a pressurized gas canister in space, at rest. With a mass "m" of gas inside of it at a pressure "P".
Next the valve of the canister is opened. The canister will accelerate in the opposite direction to the valve opening. When all the gas has left the canister, it will be moving...
I mean - when they form.
What are typical gas densities at lunar crater rim when the crater is made by a comet? An asteroid?
Both a comet and an asteroid, hitting Moon at several km/s, initially heat up to several thousand K, and even asteroid produces some vapour... at hypocentre.
However, by...
Hi Everyone.
Can anyone give me some hints which will point out how to solve this problem, particularly using 'the formalism of Ex 21.25'.
I've kicked this around for a couple of weeks now and I haven't been able to come up with anything.
Regards
TerryW
Hi, I tried looking for similar topics but nothing really solved my problem.
How can I calculate the average gas flow on a syringe that was compressed over time, if the starting and ending pressure and volume are known?
I am guessing there must be an equation which can relate these variables...
I am studying Ideal Bose Systems (Chapter 7) from the book "Statistical Mechanics" by Pathria and Beale (4th Ed. - 2021). ##\require{physics}## ##\require{cases}##
The authors have derived the following relations: $$\begin{align}
\dfrac{P}{k_B T} &= \dfrac{1}{\lambda^3} g_{5/2}(z)...
Hello,everyone!
Recently i am doing an experiments about electromagnetic induced transparency in 85rubidum gas.
I have two light source,which use the polarization spectrom frequncy stablizaiton technology to make them stable.One is used for probing light,and the other one is used for coupling...
Hello :
i was watching the news , and it was all about how Europe will start the coal factories again for energy generation
had a question related to reduction of coal consumption for energy generation
1 ) could we use coal fine particles instead of chunks of coal that will burn more...
Hello,
I am trying to solve a problem about an open Gas Turbine. The given information would be:
- An open gas turbine draws in air from the surroundings having the m, cp, T1 and constant kL with the next values:
,
- The air flow is heat over natural gas supplied:
- The pressure ratio is 𝜋...
Hello
What experiment or observation shows that for atoms, molecules or masses of gas, there is attraction in the sense of Newton's law (universal attraction)?
Bernadette
This is a thermodynamics question. A gas absorbs 10 000 J of heat , it releases 3000 J and does 2000 J of work. How much has the internal energy varied?
So I did 10 000 - 3000 -2000 = 5000 J so internal energy decreases by 5000 J. But the correct answer is A) it increased by 5000 J . How ?
Hi! I wanted to do some basic calculations for temperature T on a water-filled pot. I noticed something strange on my calculations, and couldn’t figure out what was wrong...
So here it is:
The ideal gas formula:
k=PV
The actual formula Relates equally the product PV with the a constant...
I don't know if this is really stupid, but why isn't Earth's core a gas considering that its hotter than the temperature at which each of the metals turn into a gas?
I will summarize briefly my reasoning for both letters, since the answer is immediately after that:
A) The work is quasi-static, and the pressure is approximatelly constant and equal to the atmospheric pressure, so the works is $$W = -p\int dV = -p_{0} (V_{0}-V)$$
B) The work is fast, fast...
I am a beginning graduate student and I've been assigned a paper which uses landau levels for 3d fermionic gas in uniform background magnetic field. I am having trouble finding a proper source which deals with solution of dirac equation in such a case. With the two papers that i have found which...
The image above is the solution posted by the book. I can follow the reasoning that has been used, but i have a trouble particularly at the first equation itself.
Why should $$n = 2 \rho / m_{H} $$ instead of $$n = \rho / (2m_{H})$$, since the mass os a molecule of hydrogen is two times the...
Hi,
I’m looking for formula to find the energy stored in a compressed gas for non ideal gases, for example, argon. The formula should also include the thermal energy caused by compression.
Thank you in advance.
As we know, dipole can be only arranged either parallel or anti-parallel with respect to applied magnetic field ## \vec{H} ## if we are to use quantum mechanical description, then parallel magnetic dipoles will have energy ## \mu H ## and anti-parallel magnetic dipoles have energy ## -\mu H##...
Hi,
Originally, the absolute temperature was thought to be around -273 Celsius around 1750 and it was the result extrapolation of of ideal gas law as shown below. I find it hard to phrase my question. But the question is how come they were so confident that the relationship between the volume...
I'm building a gas supply system that will dump half the contents of a compressed gas cylinder of nitrogen in 10 minutes. I need to ensure the output delivery pressure doesn't fall below a certain limit because of cooling during the gas expansion. If the cooling effect is excessive, I will...
Question:
Answer:
In the third last line of working, I do not understand why the pressure variable is changing? Shouldn't pressure remain constant and only the Volume change?
Hello my friends. I would like to know if you guys are aware of some site or paper that provides informations about gas. That is, i would like to know the energy band in which the ionization of a gas is high, and also the energy in which multiple scatter is high. The gas need to be Argon of Neon.
I assume the system starts from rest so the total initial momentum is zero.
Let:
M = mass of trolley + cylinder
m = initial mass of oxygen
Δm = mass of ejected oxygen
u = speed of ejected oxygen
Conservation of momentum:
0 = (M + m - Δm) . vmax - u . Δm
1) Is my equation correct?
2) I...
Hi,
I have to found the number of microstates for a gas of N spheres of radius r and volume v in box taking into account the reduced volume after each sphere. V sphere << V box.
I'm struggling to find the microstates in general.
I don't see how to find the number of microstates without knowing...
Hi, this is a question from my textbook that I can't quite make sense of. I don't really know where even to begin, to be honest. The only thing I can think of is that the bead is at equilibrium, thus the force of gravity is equal to the pressure exerted by the gas. I don't know where the heat...
Suppose we have a cylinder with one wall guard by a demon. Inside is one gas molecule moving left and right for simplicity.
Now we want to closer the wall (compress the gas) without doing work. The job of the demon is push the wall closer when the gas move left and lock the wall when the gas...
A gas with a volume of 8m^3 with a temperature of 400K gets warmed up to 550K with a constant pressure of 200Kpa. How much work has the gas done to the environment?
I think i might need to use the ideal gas law for this which is:
( P * V / T = N * K ) Where V is volume, T is temperature and N...