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
Questions are attached to this thread.
Homework Equations
P =mv (P is momentum)
P = F/A (P is pressure)
F = deltaP/delta t (P is momentum)
The Attempt at a Solution
I have managed to do questions a-e which I was very happy with but then moving onto the extension has made me...
https://www.physicsforums.com/attachment.php?attachmentid=20388&stc=1&d=1252066499When the partition removed, gas flows into the vacuum until all system has a uniform pressure. Now, is it possible to calculate the work?
Let's say gas is not an ideal gas.(Freon 12)
We know the volumes of both...
Qn : https://www.dropbox.com/s/dpcws9q4bjpzvtp/20151123_112037.jpg?dl=0
Why is option A and C wrong or correct?
My attempted answer :
A :A is plausible as if the piston is suddenly moved inwards, the gas molecules bounce off the piston at higher speeds
Since Temp proportional to rms speed...
Homework Statement
A gas has the following equations of state: P=\frac{U}{V} \,\,\,and \,\,\,T=3B\frac{U^{\frac{2}{3}}}{N^\frac{1}{3}V^\frac{1}{3}}
where B is a positive constant. The system obeys the Nernst Postulate (S tends to zero as T tends to zero). The gas, at a initial temperature T_i...
Homework Statement
I have the following task:
Homework EquationsThe Attempt at a Solution
But I don't understand how to solve it. Can somebody help me?[/B]
Hi, PF! I recently solved a problem from BSL which asked to analyze the following system used for determining the diffusivity of a binary mixture of gases.
The left portion of the system, from the left bulb up to the stopcock at the middle of the tube, is filled with gas A. The right portion...
If you try to mix water and sand, the sand will mix around and eventually fall to the bottom. Sand and water can't make a solution, so they separate. However salt and water can make a solution, and they don't separate. If air is a mixture, why don't the gases separate?
1) So, pretty much what...
We have 2 (insulated) partitions, one with the gas, another vacuum, separated by a stop cock. We remove the cock, letting the gas expand into vacuum .
I understand that since there is no opposing force on the expanding gas ,the work done by the gas is zero .
But work done by gas is given by...
Suppose we have an insulated cylindrical container with a piston inserted from one end. Suppose the volume confined by the piston is full of a hot gas. Now let the gas drive the piston so that the volume is increased.
Did the entropy of the system decrease because some of the energy of the...
Homework Statement
1 mm3 of gas at normal pressure and temperature contains about 1015 particles. Considering the particles as point-like and classical, provide a rough, conservative estimate for how many hard drives would be necessary to store the initial conditions of all gas particles. (As...
Homework Statement
The task is the following:
Homework EquationsThe Attempt at a Solution
I calculated the derivatives for Vm (crit) and set them = 0, but somehow I can't solve the equation to obtain Vm (crit) on one side alone.
This is how far i managed to do it:
Can someone help me?
According to standard cosmology theory the physical momentum p of both massive and massless particles decay like:
$$p \propto \frac{1}{a(t)}$$
where a(t) is the scale factor as function of cosmological time t (for a derivation see page 12 in the following lecture notes...
I am really stuck at this question.
I tried to get the equation of volume with independent variables P and T, but the equation itself does not give a nice form, and thus I cannot get the derivative of V with respect to P. What should I do?
Hi Everyone,
So I seem to have many problems understanding the Psychrometric chart and its physical meaning. First of all, I would be so thankful if you could introduce me a source which can be useful to physically and fundamentally understand the dew point, effect of pressure, humidity... and...
My daughter has the following homework problem we need assistance in confirming if we've understood and completed correctly.
Homework Statement
The Volume goes from 2.00 Liters to 7.00 Liters, the temperature changes from 800 kelvin to 150 kelvin, and the number moles of gas is quadrupled on...
Does anybody know of a way that I can protect a Google Sheet in such a way that it can only be edited via scripts?
Ultimately I'm putting something together that acts as a very poor man's ticketing system. I have information displayed in a sheet and a set of buttons with scripts attached to...
I'm trying to compress a gas at max 300 psi. I'm making an air tank that will move a small turbine to make electricity. The problem, as I found out, is that 1L at 300 psi is not that much air and I need it to run for about a minute. When I fill my tank with air from a compressor, i run out of...
hi,
so i want to ask why is the inert gas pressure in an incandescent bulb should be low?
i thought that when the gas pressure is high, more 'free' tungsten atoms can collide with the gas particles (since the gas particles move at higher speed) and bounce right back towards the filament. hence...
Homework Statement
I'm given a initial and final pressure and temperature of an ideal gas to solve for the work done after it expans in a polytropic process (n=1.2)
Homework Equations
W = integral of P*dV
PV = nRT
PV = RT*
PV = mRT
PV^n = Constant
The Attempt at a Solution
I get W = integral...
1. For a van der Waals gas πT=a/Vm2. Calculate ΔUm for the isothermal expansion of nitrogen gas from an initial volume of 1.00 dm3 to 24.8 dm3at 298K. What are values for q and w?Homework Equations
I looked up a for N2 gas to be 1.352 atm*dm6/mol2
dU(V,T)=(∂U/∂V)TdV+(∂U/∂T)VdT
(∂U/∂V)T=πT...
When we discuss about Gas Law : [Charles Law, Boyle Law and Gay Lussac Law ] are they still applicable at super low volume and temperature. At such conditions, the gases would undergo phase transition and convert to solid. So will the Gas Laws still be applicable at that stage??
Homework Statement
A gas in a piston-cylinder assembly undergoes a process for which the relationship between pressure and volume is pV2=Constant. The initial pressure is 1 bar, the initial volume is 0.1 m3, and the final pressure is 9 bar. Determine the final volume and the work for the...
I found this: http://adsabs.harvard.edu/abs/1992A&A...259L..31B document that describes how the X-Ray emissions from galaxy clusters are used to calculate the mass of the cluster. I'm unable to follow the steps to calculating the gas mass.
Specifically, in section (2) there is a formula for...
Homework Statement
Assume that in an alternate universe, the laws of physics are very different from ours and that "ideal" gases behave as follows:
(i) At constant temperature, pressure is inversely proportional to the square of the volume.
(ii) At constant pressure, the volume varies directly...
Hopefully this question makes sense; when talking about solubility of a gas does this have any relation to its ability to mix with another gas?
i.e. gas solubility in gas, versus, gas solubility in liquid
In ultrasonic cavitation some say that a more soluble gas can more easily enter the...
Moderator's Note: THIS HOMEWORK WAS POSTED IN ANOTHER FORUM, SO THERE IS NO TEMPLATE.
calculate the change in entropy suffered by 2 moles of an ideal gas on being heated from a volume of 100L at 50C to a volume of 150L at 150C. for the gas Cv=7.88 cal/moleC.
I'm really confused in entropy and...
... becomes a plasma?
I am trying to find information on the species that will be present when a gas is broken down into a plasma for different types of gas and temperatures, is there a list somewhere, please could someone give me an idea of where I should look for this information?
Also am I...
Homework Statement
One m3 of an ideal gas expands in an isothermal process from 760 to 350 kPa. Determine the specific work done by the gas.
Homework Equations
ω=W/m
1W2=mRTln(P1/P2) = P1V1ln(P1/P2)
P1V1=P2V2
The Attempt at a Solution
P1V1ln(P1/P2) = (760)(1)ln(760/350) = 589.29kJ...
Homework Statement
96 grams of oxygen and 50 grams of hydrogen gas occupy separate, equal sections of 200 liter tank. The divide is removed and the gases are allowed to mix and react with each other. Temperature is kept constant at 120 degrees celsius
2. Homework Equations [/B]
b) find the...
In my lecture, we were told that a nitrogen with a negative 3 charge has the largest radius compared to most of the other atoms in the same period. How is that possible? It has more protons attracting the valence electrons closer to the center, but the prof said that because three electrons are...
Does laser light from a powerful violet laser with wavelength 405 nm create significant ionization in a gas (Hydrogen or Helium) if shone through it? Will there be a streak of ionized molecules/atoms in the beam, so to speak? Can that ionization be detected easily with a voltmeter? How effective...
Hello, thanks in advance for your help,
I am not a physicist, however have a fairly good grasp on mathematics, also this isn't homework or an assignment but a real world problem.
Currently trying to create a system with a nebulising gas at a linear velocity of 350 m/s. The calculations...
Hi guys,
I want to design a gas burner and combustion chamber.
I use natural gas as fuel. I want to control air to fuel ration, so air flow has to control.
I have an air compressor as air flow source.
Clearly, it's needed a mixture tube before the combustion chamber.
Now I have some...
Homework Statement
Homework Equations
Pv=nRt
The Attempt at a Solution
I already calculated V for a single molecule = 3.99x10^-23 m^3 and the cubic root of this volume gives 3.42x10^-8 m. However, I don't understand what I should do next. What does it mean to compare the value I obtained to...
Can someone please help me with the following proof ...I'm stuck and not sure if I'm even on the right path.
Prove that What I've done so far;
if U = f(T,V)
dU = (∂U/∂T)v dT + (∂U/∂V)t dV
Cv (non ideal) = (∂U/∂T)v
Using dU = TdS - PdV and Maxwell relation (∂S/∂V)t =(∂P/∂T)v,
(∂U/∂V)t =...
Homework Statement
My problem is with the last line of the derivation. Usually, we take the rate of change of momentum (force) to be change of momentum divided by the impact time. But this slide of pp showed that the traveling time of the particle in the box is used but not the impact time. Why...
Neutral hydrogen gas in galaxy clusters
Most galaxies are members of a cluster, a grouping of several to thousands of galaxies. Our Milky Way, for example, is a member of the "Local Group," a set of about fifty galaxies whose other large member is the Andromeda galaxy about 2.3 million...
Young gas giants fly close to their suns
Hot Jupiters, giant Jupiter-like exoplanets that orbit 20 times closer to their host stars than the Earth does to the Sun, can form and migrate towards their infant stars in as little as a few million years, researchers at the University of St Andrews...
Hi
I am working on Bio Gas Project and I want to know calculations/Formulas to find out elements of Generator.
I am MBA students and i have to submit my project report with to start up new firm on renewable energy.
Please submit can share your knowledge to help me.
Homework Statement
Two glass vessels M and N are connected by a closed valve.
M contains helium at 20 °C at a pressure of 1 × 10^5 Pa. N has been evacuated, and has three times the volume of M. In an experiment, the valve is opened and the temperature of the whole apparatus is raised to 100...
Homework Statement
A U-shaped tube of uniform section "S" has one extreme closed and the other one open to the atmosphere. The tube contains mercury (M) in the central part, a gas (G) to the left that exerts a pressure "p" and a column of water (W) of height h_w to the right. Then, a mass "m"...
Hey guys, I just want to make sure I went about this the right way...your input would be greatly appreciated.
Thank you in advance.
1. Homework Statement
A tire is checked before a road trip and the gauge pressure reads 220 kPa (gauge) - State 1
The same tire is checked after the trip and the...
If inert gases are added at constant volume to an equilibrium mixture, the total pressure increases. But the mole fraction of the gaseous reactants or products decrease.
Partial pressure ##p=x\cdot P## where P is total pressure and ##x## is mole fraction.
How can you say that ##p## remains...
Obviously we don't have the technology to make this work now but I would like to know how plausible this is as a concept/thought experiment. Basically the idea is to discover a gas or liquid with a very high activation energy (for some reaction) so that it can absorb an explosion or control a...
1. The problem/question is as follows:
1 mole of O2 mixed with N2 gas (PN2= 5 atm at 10 degrees celcius in a 1 L flask. What is the total pressure after 2 moles of gas is allowed to escape? How about the partial pressure of O2?
R= 0.08206\frac{L atm}{mol K}
Homework Equations
Using the ideal...
Is it possible to create a protest gas that sedates and lasts for a very long period but has a limit on its severity, no matter how long exposed? If so, may you please elaborate? This is for fiction I'm working on.
Hello all,
I have an oxygen tank that is 10 L in volume, pressurized at 500 barr (pressure can be adjusted down to 1 barr out of the tube), and I want to 'bubble' the oxygen into a beaker of water. I will simply use a tube (diameter is around 0.5 cm) connected from the tank and with the other...
I read that biodegradable waste in landfills produces methane, a harmful GHG. But didn't biodegradable waste always exist? We throw paper away, but the trees we produce paper from would have died eventually. Our organic waste comes from plants and animals that would have died eventually too. So...
Homework Statement
A sample of an ideal gas goes through the process shown in Figure P20.32. From A to B, the process is adiabatic; from B to C, it is isobaric with 100 kJ of energy entering the system by heat. From C to D, the process is isothermal; from D to A, it is isobaric with 150 kJ of...