Gas Definition and 1000 Threads

Doesn't volume of ideal gas include volume of the molecules? What I was taught in school is that, when two molecules collide, no other molecule can come around it (inside the green part in the figure) and that volume is excluded volume? Is it correct? If yes, why?

Trying to determine diffusion rate of a gas emitted from a body of water. I believe Fick's first law may apply: J = -D * (dc/dx) where: J = diffusion rate [mg/s×cm2] D = diffusivity constant (can be looked up based on type of gas and local air temperature) dc = change in concentration from...

When a helicopter float motionless the work done on it is zero.But why does it still consume energy?A similar question is why when we hold still a weight, we must consume energy(we feel fatigue)?

I am creating a two-dimensional model of an ideal gas, and I was wondering how I should determine initial velocity. Ideally, I would like for the simulation to reach a point where the velocity distribution resembles that of the maxwell-boltzmann curve — will this be achieved if I, say, assign...

Hi, I wish to write a simple simulation of gas behavior. I have two tanks, connected by a valve. When the valve is opened, the gas will obviously flow and after some time it will reach an equilibrium. I could really do with some help in calculating the rates of change of the temperatures and...

Is there such a thing as a partial temperature of a gas in a mixture? Partial pressure is commonly accounted for and used. It seems that if there are molecules of different masses colliding in a mixture, their average respective velocities in a mixture should be different based on transfer of...

If Jupiter is made of gas, how can it maintain its spherical shape without being contained in a spherical shaped container?

How do you calculate the time it take a high pressured gas to fill a chamber? I have a gas in a chamber that is at 600psi and then another chamber at atmospheric pressure. When the valve between the two chambers is opened, how do you calculate the time it would take to fill the chamber? Are...

2.1 * 10^-4m/3 Temperature 310K Pressure: 5.3 * 105 Pa So the Ideal gas formula is PV = nRT 2.1*10^-4m^3 Times 5.3*105Pa = n * Gas Constant * Temperature 2.1*10^-4m^3 (*) 5.3*105Pa = # of moles * I'm not sure what I was doing, but the whole equation stuff got hard and I stopped. I left...

This was the equation that they showed me. I thought P was for pressure, V for Volume, T for Temperature, R for Gas Constant, and n for the number of moles. Was I correct for the initials?

I need to measure trichloroethylene (TCE) in water samples using headspace gas chromatography. Obviously, I will need a set of standard solutions to make a standard curve for concentration vs area. How exactly do you prepare the standard solutions? What I don't understand is that, say I prepare...

If one considers the kinetic theory of gases, can a first order estimate of thermal transfer be performed by considering momentum exchange at the container's surface? I understand the basics of explaining and calculating pressure with the kinetic theory of gases, but if we assume energy is...

Hi All, When dealing with the kinetic theory of gases in thermodynamics, we obtain the result that the mean kinetic energy per atom is (3/2) kT. In considering different samples like 200g of liquid water or a solid cube of lead with one cubic meter, does kT still play an important role in...

In an isothermal process, for an expanding gas ##\Delta U_{sys}=0## and ##Q=-W## but then, How can we evaluate ##Q_{surr} ##? It should be ##Q_{surr}=-Q_{sys}##, but I don't know how to show it in equations. If I try to get the result through the principles: ##\Delta U_{sys}=-\Delta U...

It is well-known that the electron gas of volume V has an equation of state p=p(V) and thus has a bulk modulus $$B=-V(dp/dV)$$. Suppose the electron gas had no underlying lattice but was confined. Do phonons emit and absorb in such an electron gas at finite temperature? The reason I ask is...

I've set up a simple experiment to look at the ideal gas laws. My experiment is relatively simple in that I have a metal tube which is capped on one side. I am then pressurising the tube with air to 100 psi and locking it off. My thought is that as the pressure increased, with volume held...

I thought I should use the ideal gas law to find out moles of air that would be transferred out through the window but the temperature and volume outside is not known. Can you help me further? thanks

After the foot is released from the gas pedal, the car will naturally start decelerating. From my understanding two things are causing this: air resistance and kinetic friction. From my understanding also, in a vacuum and in a place where gravity is relatively small, the car would not...

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Please refer to diagram. V1 is open initially then V2 is open for 5 minutes for pressure to equalize. V1 and V2 are then shut. V3 is opened. What is Vol 2 ? P(final)*V(final) = n(final)* R*T => (Vol1 + Vol2) = n(final)*R*25C/ 0.070 Torr where n(final) = n(Vol1) + n(Vol2) If I shut V3, I...

For the reversible expansion of an ideal gas the heat flowing out of the surroundings and into the system is equal to the work done by the system. Since both system and surroundings have the same constant temperature the entropy increase of the system is equal to the entropy decrease of the...

I have a problem that i cannot solve despite my best efforts. I do realize not all information here is relevant, but i still included it so you could get the full picture. Imagining we have a cylinder that is filled with dry air (normal air without water vapor) that has a fixed volume of 8,5...

Here, i have provided the description of the mean molecular weight from my course notes as well as my workings. I'm not sure about my values for X and Y. It states that X=1 if all of the hydrogen is ionised which i think the 1 represents 100% hydrogen but the core is also made up...

Attempt: P_1 (initial pressure on the left section) P_2(initial pressure on the right section) T_f, P_f (final pressure for both sections) P_1 (V/3) = N/2 k (3T/2) P_2 (2V/3) = N/2 k (T/2) P_f V/2 = N/2 k T_f Resulting in 4 unknowns and 3 equations... Not enough to find T_f...

My first most obvious attempt was to use the relation ##<\epsilon> = \frac{3}{5}\epsilon_F## and the formula for kinetic energy, but this doesn't give the right answer and I'm frankly not sure why that's the case. My other idea was to use the Fermi statistic ##f(\epsilon)## which in this case...

I'm having trouble wrapping my head around some thermodynamics and ideal gas law concepts. I don't have a specific textbook question but Just a concept I'm having trouble with. What I'm struggling with is understanding some of the relations between pressure, volume and temperature...

Hello Team, Had a shower thought, and thought I spend a few minutes online with people much smarter than I to throw an idea at... So, I have a light weight truck. Say a little dodge dakota pickup that weighs +/- 3000lbs. I want to take out the motor and replace it with a little baby 20hp...

This is the final question on my assignment and I'm clueless as to where I should even start as the lesson seems to give no guidance. Help would be massively appreciated!

I understand that ##\dot m=\rho Q## and ##{\dot m}_{in}= {\dot m}_{out}## . So one can say that ##\rho Q_1 = \rho Q_2##. But I'm not sure if that equation is correct. I don't know if the density remains constant, or the volume flow rate. And then how I'm also supposed to tie a state equation in...

hii, I'm try to calculate the pressure (in bar) needed for a certain flow rate 3 L/min of Argon gas given the following setup: - I have a tank of Argon gas and the line pressure can be between 0 bar to 5 bar. - The gas will flow out to the open air in the end. - My pipe has an internal radius...

I have the definition of change in internal energy. $$ \Delta U = Q - W $$ I can get the work by $$ W = \int_{V_1}^{V_2} p dV = p \Delta V $$ however the pressure isn't constant so this won't do. ## W ## is work done by the gas and ## Q ## is amount of heat energy brought into the system. I'm...

My work was as follows: The first law states ##dU = TdS - PdV##, and thus $$p =- (\partial U/\partial V)| _S$$ $$U = -RT \ln(V-b) + f(S)$$ To determine ##f(S)##, I reasoned that in the ideal gas limit of ##b = 0##, ##U## should take the form of the ideal gas' molar internal energy ##\frac{3}{2}...

Attempt:

Hello all, Thank you for reading my topic. My client asked me to make calculation sheet for gas pipeline like the image below. Can someone help me to make this? (i'm new in this system, need to learn and study. So please help me) How to calculate the required pressure at connection point if...

I first found the partial pressure of ethanol at 70 degrees using Antoine coefficients: Coefficients: A 7.68117 B 1332.04 C 199.2 Equation: And found a partial pressure of 0.7 bar...

This seems like a simple thermodynamics question but I would like clarification. So the absolute critical temperature is 132.5 K (-221.17 F) and the absolute critical pressure is 3.77Mpa (546.7 psi). I understand that for temperatures above the critical point, a pure substance undergoes an...

Hi PF! I have a tricky problem that I'm trying to model, and none of the typical textbook examples cover this--or they only cover it tangentially--so I was hoping to get some insight here. (Couldn't find a "Thermodynamics" section of the forums so if there's a better place to post this, please...

When salt (polar) is added to water (polar) it makes the water more polar and causes the oxygen (non-polar) to be "driven" from solution. So I'm assuming this is an electrostatic repulsion(?). Aside from salt what other solutes would cause this to happen? Would a solute have to have very polar...

Hi all, I have an issue trying to understand the following paragraph from Blundell's book. How, exactly, does the definition of ##\mu_0 = E_F## "make sense"? In the sentence after 30.21, it seems to say that the mean energy for a system with ##N## particles differs from that of a system with...

I know that in a Fermi gas, the two common responses to a lo field are Pauli par. and Landau dia. and the last becomes the H-VA effect My question is, it is the same treatment in degenerated Fermi Gas?

Homework Statement 1kmol of multatomy(I hope you understand - gas with many atoms) gas is heated for 100K (conditions of free expansion). I have to calculate the amount of heat supplied to gas. I have no idea how to do it. The right answer is 3320kJ Homework EquationsThe Attempt at a Solution

1. The problem statement, all variables and given/know Given: Nitrogen: 2g, it takes 820cm3 at 2 atm pressure. What is the temperature (T) of gas? Answer: 280K Homework Equations P*V = n*R*T P - pressure V - velocity n - moles? R - constant, 0.0820 ? when I use liters, atm T - temperature in...

Homework Statement In principle, does a hot gas have more mass than the same gas when it is cold? In practice, would this be a measurable effect? Homework Equations E = γmc2 The Attempt at a Solution Since there's more energy, there's more mass. But I don't think these effects would be...

If is yes, under which conditions?

I am currently working in astromagnetism. My question is, somebody knows if a fermi gas (degenerate electrons) can increase or decrease de total magnetic field due to an influence of an external magnetic field and if somebody have information about that. I know that an external magnetic field...

<< Mentor Note -- Two threads on the same question merged into one thread >> How does the maximum Power equation change if there's an angle to the way the wind falls into the wind turbine's blades? Example, when it falls vertically to the blades, it's Pmax= 8/27Sρu13 But if there's for...

How can I see, by looking at a band structure if the substance in question can be viewed as a free electron gas (FEG) or not? What characterizes a FEG in a bandstructure plot? Thanks in advance!

My concern is an electron tube. From what I understood so far, gas molecules will have an average velocity derived from the Maxwell distribution, and that velocity will influence in the electron collision frequency. I can't see clearly though how the electron velocity itself in the presence...

Hello all. I have a question about gasses and pressure: Is there a way to calculate how strong a material making up a balloon has to be to withstand a given pressure difference between the inside and outside? In other words, if I have a balloon I need to fill to a pressure of 10atm inside vs...

In the derivation of finding pressure exerted by a gas using kinetic theory of gases I am not understanding why the time between two collisions is taken as the time for rate of change of momentum when a particle bounces back from the wall. please help me