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.
Homework Statement
What is w when a gas is compressed from 42.1 L to 25.1 L using a constant external pressure of 739 Torr? Remember to include a "+" or "−" sign as appropriate.
Homework Equations
W = -P(dV)
The Attempt at a Solution
Pressure = (739 Torr / 760 Torr)*(101.325 kPa)
W =...
If considering the free expansion of an ideal gas adibatically such that the final volume is double of the initial volume.
Since dU=0 for free expansion ,which implies Ti=Tf for ideal gas...(1)
From adiabatic relation ,
TiViγ-1=TfVfγ-1, to satisfy (1) ,γ-1=0
and for ideal gas Cp-Cv=nR
or...
Obviously expanding the gas cools it down. I'm interested if you could boil water and then expand the high pressure steam to cool it down to 0°C. Or are there subtler thermodynamics that would prevent this?
A friend of mine and I have been discussing how to apply the first law of thermodynamics to analyze the quasi static expansion of an ideal gas in a cylinder featuring a piston having both mass and friction (with the cylinder). We have identified two different systems that can be used in the...
Homework Statement
Homework Equations
pV=nRT
The Attempt at a Solution
I know the volume of the cylinder, which is Al. So I plugged this into the ideal gas law formula, and got answer B. However, the correct answer should be D. I see the Boltzmann's constant there in the equation, and I do...
Hi all,
I have a few questions concerning cars and HP, I will post the first question now and I think the answer will determine if I need further help. I will prefeace my question with the disclaimer that I have very limited automotive knowledge.
If 2 cars that are operating at the same...
Homework Statement
An ideal gas has a molar mass of 40 g and a density of 1.2 kg m-3 at 80°C. What is its pressure at that temperature?
Homework Equations
PV=nRT
R constant= 8.314
n= number of moles
T= tempreture in kelvin
density=Mass/ Volume
The Attempt at a Solution
i simply solved it like...
Hi everyone, I'd really appreciate any help with this problem:
A helium cylinder for the inflation of party balloons hold s 25.0L of gas and is filled to a pressure of 16500kPa at 15 degrees celsius. How many balloons can be inflated from a single cylinder at 30 degrees celsius if the volume of...
Homework Statement
From near to the center of the solar disc, Fe I line emission from point X shows a spectral line with components 666.823, 666.830 and 666.837 nm, around the rest wavelength of 666.800 nm. The central component is not as bright as those at the longer and shorter wavelengths...
I am writing a document on the Joule-Thomson effect. But in my research for it I have come across something that I am not completely clear on. In my document I explained the free expansion of an ideal gas and am trying to transition/segue into the Joule-Thomson effect. However now I am having...
Hello
What is the meaning of the average velocity of gas molecules calculated by Boltzmann distribution (in kinetic theory of gases)?
Does all molecules have the same average velocity?
I was getting gas today on my way home from work, and the apparatus on top of this box truck parked in the parking lot caught my eye. Just as with unusual antennas, when I see something like this I need to take a closer look to see if I can figure out what it is being used for. (Luckily no...
Homework Statement
What is the solubility of an unknown gas in water at 1.0 atm if its solubility at 3.0 atm is 1.02M?
Homework Equations
Henry's law Sg = k*Pg
The Attempt at a Solution
Sg = 1.02M/3.0atm * 1.0 atm = .34 atm
I'm not sure if Pg, the partial pressure of the gas, is 1.0 atm or...
The ideal gas law is given as ##PV=nRT## where ##R## is said to be the universal gas constant equal to ##0.082056\frac{L⋅atm}{mol⋅K}##. ##R## is said to be a constant, and thus cannot change even if we change the values of ##P,V,n,T##.
I don't see how this is possible, because the way we found...
The ans comes out (c) if I take specific heat at constt volume to be independent of temp.
Whether the specific heat is always temp. independent for an ideal gas??
I just read a couple articles discussing the surface gravity of Saturn and Jupiter. I would expect the "surface" gravity of these planets to be much higher than that of Earth. I understand how the low densities of these planets has influence on that, but I thought mass was related to gravity in...
If a gas is suddenly allowed to expand freely and adibatically inside a container then from the first law of thermodynamics dQ=0,
My question is whether the change of internal energy would be 0 and if it then how would the work done be 0 (since accessible volume of the gas changes inside the...
Hello,
I want to develop a pressure regulator model in simscape. The model will be the springloaded direct acting system and the aim is to target outlet pressure, temperature and flow rate by giving input parameters as pressure, temperature, spring stiffness, length and preload, lever(it is...
Homework Statement
In the figure below, the volume expands while the pressure is constant. What happens when this gas expands?
A) heat is added and temperature increased
B) heat is removed and temperature decreasesd
C) heat is added and temperature decreased
D) heat is removed and temperature...
Homework Statement
In a certain process, a gas absorbs Q amount of heat and performs kQ amount of work, the molar heat capacity of the gas in terms of R, k and γ(Cp/Cv) is?
Homework Equations
U=Q+W
U=nCvdT
Q=CdT
The Attempt at a Solution
replacing U and Q with the above formulas and W from...
Homework Statement
An adiabatic isolated system is formed of three identical balloons (of unknown volume). The balloons are joined by tubes of negligible volume. Each tube has a faucet/tap that is initially closed. The balloons have different quantities of the same ideal gas.
After opening...
Homework Statement
In all calculations, take R = 8.31 J/m-K. Use the Sackur-Tetrode equation with N replaced by n and K replaced by R to calculate the changes in entropy. Also, assume that these processes are quasi-static so that the ideal gas law and the first law apply at all times. Consider...
hey!
EDIT: I didn’t post this in homework help because there aren’t any computational questions, it’s just conceptual
My assignment scenario consists of a star (blackbody) surrounded by an expanding shell of hot gas. I’m given its spectrum and it is a continuous emission spectrum. Emission...
The MB energy distribution is: MB_PDF(E, T) = 2*sqrt(E/pi) * 1/(kB*T)^(3/2) * e^(-E/(kB*T))
How do I arrive at the density of states which hides inside the expression 2*sqrt(E/pi) * 1/(kB*T)^(3/2) ? I've only seen DOS that have "h" in them.. I want it to contain only E, pi, kB and T.. This is...
I attend a trade school, majoring in HVAC (Heating, Ventilation, and Air-Conditioning). My instructor has given me information that seemingly contradicts what my textbooks tell me about Charles' Law. My instructor is not a scientist. I asked my instructor to reconcile the two seemingly...
Homework Statement
The following is the equation of ideal gas law, where p is pressure (Force/Area), V is volume, n is number of moles and T is temperature in Kelvin. What is the fundamental unit of R?
pV = nRT
A. kg^−1 · m^−2 · s^ 2 · K · mol
B. kg^−1 · m^−4 · s ^2 · K · mol
C. kg · m^4 · s...
Hello,
I am trying to figure out where my reasoning falls apart in this thought experiment:
To determine if a process "A" is reversible (or at the very least internally reversible), I try to picture a reversible process "B" that involves only heat transfer and links the same two endpoints that...
I'm looking for advice on how much power is required to compress air in a gas turbine engine - parameterised by degree of compression and mass flow.
Normal gas turbine engines have exhaust turbine(s) on the same shaft as the air compressors. They bleed some of the exhaust energy to drive the...
Homework Statement
The question is:
One kilogram of a gas with a molecular weight of 35 is contained in a balloon. The initial conditions are 27 C and 0.025 m^3. The gas is slowly heated isothermally until the final volume is 0.05m^3. The atmospheric conditions are 100 kPa and 27 C. The p-v-T...
Hi,
Can some one point me to where I can workout the amount of force required to compress a niitrogen filled ram.
Ram has an 80 mm bore and 172 mm stroke. We have filled it with nitrogen to both 1 and 1.5 bar.
thanks
Brett
When do we use the equations of curvature drift ( ΔΒ⊥Β) V∇B= ±1/2u⊥rL (B x ∇B)/B2 and the general VF= c/q (F x B)/B2?
For particles like muons and protons, do they need different equations to calculate a gas' drift velocity, when the gas is made of protons or muons instead of electrons?
Am I...
When do we use the Boltzmann equation for density in a Fermi plasma?
n in [cm-3]
and when do we use the ρ=m/V, ρ in [Kg/m3 ]
(this is not an example, I just added the equations to make my question more understandable)
Is the ideal gas only when we have electron and ions? Is the Boltzmann...
When an ideal gas,in a piston kind of system and whose equilibrium state is mentioned, is allowed to expand (piston is allowed to move and not gas leaking )against a constant external pressure very quickly, then, is the work done by gas zero or not zero ?
The argument for work being zero is...
Homework Statement
Basically the units of the Canonical Partition Function within the logarithms should be zero
Homework Equations
The Attempt at a Solution
N here is a number so we ignore the left logarithms, applying a "Unit function " for the terms within the logarithm...
Homework Statement
Consider a cylindrical parcel of air of area A and infinitesimal height dz. If this air parcel is to remain stationary, the difference between the total pressure forces exerted on its top and bottom faces must be equal to its weight. Use this information and the ideal gas...
If I have a box evacuated of air with 5 of the sides mirors and one side a heat conductor. will the photon gas inside have photons that get absorbed by the heat conductor and re-emitted when the photons strike the heat conductor
Homework Statement
How can we calculate the velocity at stack tip if the distance of larger diameter is 2.5 m?
I think i cannot use the equation of V1A1 = V2A2 because they may have some effect from 2.5 m of distance.
Thank you very much.
Homework Equations
Q1=Q2
The Attempt at a Solution...
In a gas turbine engine(in aircrafts), why doesn't the gas after expansion move backwards towards the compressor?
.How is it that it expands away from the compressor(rotating the turbine blades)?
Will the pressure of air at the end of the compressor before the combustion chamber be higher than...
In the first volume of his lectures (cap 6-4) Feynman presents Maxwell's distribution of velocities of the molecules in a gas.
And, referring to the PDF graph he says:
"If we consider the molecules in a typical container (with a volume of, say, one
liter), then there are a very large number N...
Hello,
I'm a chemist and I'm currently working on my PhD on materials science.
I'm trying to determine the pressure difference necessary to achieve the desired gas flow inside a chamber. The scheme of the chamber is the following:
I have a big chamber which is evacuated to 0.2 bar, and another...
I need to pressurized argon gas from 1 bar pressure to 2 bar pressure. Flow rate outlet is 0.5 LPM. Can anybody suggest me a pump or compressor which is small in size? Minitiarised diaphragm seems good option but is it right one?
I've got a question that requires me to use the Van der Waals equation in the form:
p(V-b)=nRT
The process is isobaric, the volume changes from 1m3 to 2m3, and there is 1 mole of the unidentified gas.
Ultimately, I need to find initial and final values of T. So I rearranged the formula...
The main aim of my question is to find time taken by gas filled tank while emptying (from full to zero) it into atmosphere?
I require a set of equations which might be used in the calculation of such a situation.
Known parameters are:
1. Pressure inside the gas tank.
2. Dimension and shape of...
I would argue that if you are computing the work done by an expanding gas in a frictionless piston, in an irreversible expansion where the inner pressure is greater at all times than the (constant) outer pressure, that you should integrate the internal pressure over volume change, not multiply...
OK, so I need to bring this one to the forum.
I keep somewhat fanatical records on my vehicles. 69,450 miles ago there was a front end alignment done and the toe-in was set to +3/16" on the front end. My truck is a Toyota 4x4 which sees frequent off-road trips. Just over 1k miles ago I found...