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.
The problem is from the book "The Principles of Thermodynamics" by ND Hari dass.
It looks trivial problem, but I am not able to form logical arguements for going into next step.
For example, It seems like first gas has equation of state ##PV =nRT## and second has ## \left( P_2 +\frac{a}{V_2^2}...
I suppose that the temperature is the same for the helium as well as for the air. So
##\frac 43 \pi r^3 \rho g >m_{He}g+4\pi r^2 \sigma g##.
I would determine the density of air from ##p_0 \mathrm d V=\frac{\rho \mathrm d V}{M_a}RT##.
So
##m_{He}<4\pi r^2\left(\frac{p_0M_a r}{3RT}-\sigma...
If a gas flowing through a tube would meet two orifices with different diameters in the same cross section, how much of the gas would flow through each orifice and what would the gas velocity be in dependence of orifice diameter?
Hi !
To me it seems linda cycle can not liquidize nitrogen.
Please explain me, can it liquidize N2? Here is how I come to this result:
Imagine compressor take nitrogen 1bar 300k and gives 200bar hot, but cooled to 200bar 315k.
Next n2 is cooled in counterflow heat exchanges (hex) by cool n2...
For this 19(a),
The answer is 0.137 atm.
My working is
##P_{gauge} = P_f - P_i##
##P_{gauge} = \frac{nRT_f}{V_f} - \frac{nRT_i}{V_i}##
##P_{gauge} = \frac{nRT_f}{V} - \frac{nRT_i}{V}## since volume does not change
##P_{gauge} = \frac{nR}{V}(T_f - T_i)##
However, I am not sure how to go from...
I ran across the following problem :
Statement:
Consider a gas of ## N ## fermions and suppose that each energy level ## \varepsilon_n## has a multiplicity of ## g_n = (n+1)^2 ##. What is the Fermi energy and the average energy of this gas when ## N \rightarrow \infty## ?
My attempt:
The...
Hey everyone, I have an attempt at fully solving this problem (my final pressure is ##p_f = 5373,64 hPa##, final temp. is ##T_f = 303,15K = 30C##), but this exercise confuses me very much.
First, I have not used the masses in my calculations and I'm pretty sure my prof. accidentally copypasted...
Well, it's been nearly 10 years since my last post, and it's been about that long since I've thought about ideal gases, so here we go :smile:.
Description of Setup
I have a system that uses compressed gas cylinders as a source to slowly purge an optical payload. The source is 12x compressed...
I want to work out how to calculate the pressure change in a gas cylinder if it is used to fill another cylinder to a lower pressure.
For example, if a 50 litre gas cylinder initially at 200 bara is used to fill a 600 litre cylinder from atmospheric pressure to 1.5 Bara. What would the change...
For this problem,
The solution is,
However, why must we use absolute temperature for the ideal gas law (i.e why can we not use Celsius for T)
Many thanks!
Obviously, we know intuitively what they mean, but it seems that physicists have developed an objective definition for all of these.
If I were to guess, I'd say that:
- a gas is vastly less compressible than a liquid or solid (i.e., which are considered in thermodynamics as basically...
Hi all, i'm the proud owner of a 1972 VW T2 Danbury Pop top campervan. Out of the factory these were fitted with 4 x long spring loaded struts which (when new) provided some lifting power to pop the roof up. Mine are now 50 years old and provide no assistance lifting / holding the roof in...
As in title:
Plugging in the definition is straight forward, I am too lazy to type, I will just quote the book Fetter 1971:
Up to here everything is very straight forward, in particular, since we are working on free electron gas, ##E=\hbar \omega##
However, I have no idea how to arrive...
im learning thermodynamics and currently in a lesson about thermal processes. one process has constant pressure and before diving into equations or any proof the book provides a figure of a gas cylinder. the cylinder has a movable piston/lid on one side. the book then says "...and the piston end...
Hey there,
Trying to confirm whether or not these substances emit formaldehyde gas when subject to heat of hair straightener and hairdryers. Both were ingredients in a keratin treatment i used at home and i had a crazy reaction (irritated skin, eyes, hair, nose and lungs) in the process of...
For part(b),
My solution is,
##\Delta E_{int} = Q - W = \frac{3}{2}(P_fV_f - P_iV_i)##
##Q = W + \frac{3}{2}(P_fV_f - P_iV_i)##
##Q = 4000 + \frac{3}{2}((1 \times 10^6)(6 \times 10^{-3}) - (3 \times 10^6)(2 \times 10^{-3})##
##Q = 4000 J##
However, according to the solution b. ##−4000 J##
Can...
For this problem,
dose anybody please give me guidance how they got 74 K as the answer? Note that chat GPT dose not give the correct answer (it gives the temperature of the gas is 1500 K).
Many Thanks!
For this derivation,
I am not sure why the bit highlighted in orange is not positive since the displacement of the piston is downwards in the same direction as the force applied.
Many thanks!
An insulated container (constant volume, adiabatic) contains an Ideal gas with pressure P1 and temperature T1.
We open the container's hatch for a few seconds and let some particles escape from the container, then we close the hatch again. We know container's pressure has reduced by exiting...
Question: Two samples of a monatomic ideal gas are in separate containers at the same conditions of pressure, volume, and temperature (V = 1.00 L and P = 1.00 atm). Both samples undergo changes in conditions and finish with V = 2.00 L and P = 2.00 atm. However, in the first sample, the volume is...
I'm reading through Hohenberg's seminal paper titled: "Inhomogeneous Electron Gas" that help lay the foundation for what we know of as Density Functional Theory (DFT) by proving the existence of a universal functional that exactly matches the ground-state energy of a system with a given...
I have considered two scenarios:
1) A particle that has just collided with the wall at ##z=L## is moving with a velocity ##v_z<0## moving away from the wall. Hence, the probability that this particle has of colliding again is ##0##, so its distribution is also ##0##.
2) A particle moving with...
I have been trying to make sense of the derivation of pressure under Kinetic Theory of Gases chapter, but it's not making sense to me when the impulse momentum equation is used for the collision between a gas molecule and the wall of the container.
The book says that for the elastic collision...
Ref: Van der Waals Equation @ Wikipedia
The above paragraph is explains how intermolecular attraction reduces the gas pressure, assuming that there is no attraction between walls and particles.
In practice, would there be a change in pressure from one kind of wall to another, if we ensure...
Hi all, in this question i was asked to find the percentage change in the density, my approach was as following, first i find the change in volume due to putting the gas into the other vessel as:
$$
P_{1}V_{1}=P_{2}V_{2}\;\; → \;\;V_{2}=\frac{P_{1}}{P_{2}}V_{1}
$$
now i use
$$...
To solve this problem I used two equations:
$$
PV=nRT,
$$
where ##P## is the pressure, ##V##the volume, ##R##the gas constant, ##T##for temperature and is##n##the number of moles, related to the
mass ##m## and molar mass ##M## by
$$
n=\frac{m}{M}.
$$
It will be also necessary consider the...
Can someone please tell me where I am wrong, here goes the question:
to a container filled with gas, U shaped pipe is attached, as shown in the picture(picture below). What is a gas pressure in the container if the height of the pillar of mercury in barometer is 740 mm?
The way I solved it is...
Hi all,
The idea is to generate as much as possible water steam from heat of internal combustion engine exhaust gas. The so called steam generation device is a simple sloped engine exhaust pipe where water from engine cooling and hot gas is fed at the top and all the mix is exiting at the...
(1) Incorrect, since the root mean square speed(c^2）is directly proportional to the temperature, but it will just affect the average kinetic energy, doubling the k.e., but not related to the potential energy.
(2) Correct, since the volume of gas is directly proportional to the temperature
(3)...
The answer given for part (c) in the back is that temperature doesn't change as the gas in cylinder A expands to fill cylinder B.
The thermodynamic system here is composed of the two cylinders A and B joined by some pipe.
But, I cannot find a satisfactory explanation for temperature...
There is no atmosphere pressure.
My work :
pA=k(x-x0) => pA=(k/A)(V-V0)
But this should be false beccause I want to use W=∫PdV to find work done by the gas but my final anwer is wrong ...
Please guide me where my mistake is if you have enough time. Thanks.
Homework Statement:: I am trying to understand a formula given in our book for determining molar heat capacity of an ideal gas under different thermodynamic processes using a single formula, but it is confusing. The exact formula for different processes is in the screenshots below. Can someone...
It is a 1D Tonk gas consisting of ##N## particles lined up on the interval ##L##. The particles themselves have the length ##a##. Between two particles there is a gap of length ##y_i##. ##L_f## is the free length, i.e. ##L_f=L-Na##.
I have now received the following tip:
Determine the...
I have a question about the temperature of HII gas. According to Table 1.3 in Draine's book (physics of the interstellar and intergalactic medium) this temperature is T~10^4 K.
I get a similar value by using the Saha equation for a hydrogen gas.
However, a naive estimate of the same temperature...
P1=1.9 and P2=4.8.
Question: what is the total change in internal energy
This is what I have so far but it is still incorrect I believe:
U= (3/2)(1/2)(2.9)(1.01x10^3)(8x10^-3)
Where am I going wrong?
Anyone outright experience or understand tips and tricks to apart/separate a rubber-ended hose with the gas regulator/connector (as the right pipe mouth below but sorry no rubber-end hose pic) ?
It indeed so hard
so any clear idea, with keep everything intact unbroken on mind, how to do and by...
Hi,
I am not quite sure if I have understood the second task correctly, but I proceeded as follows.
It's about what happens to the isothermal compressibility when the free energy becomes minimal. In the first task there was already the equation ##\kappa_T=\frac{1}{V}\Bigl( \frac{\partial^2...
Molecular speed of gas is generally $$v=\sqrt{\frac{3RT}{M}},$$where R is gas constant and M is molecular mass. Can we use this formula for the air as well, when the air is a mixture of different gasses?
For now it is only about the 1 task
If the task states that:
You can approximate that their dynamics in water resembles that of an ideal gas.
Does it then mean that I can take glucose as the ideal gas and then simply calculate the entropy for the ideal gas?
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...