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.
A question in regards to rolling resistance. Am I wrong in thinking that not everything you hit on the road with your tire effects your gas mileage? Don't tires have a tolerance in terms of how much energy they can absorb before it effects your traction, therefore effecting your gas mileage...
In nuclear physics we have talked about the liquid drop model and the fermi gas model. My question is can a Fermi liquid and a Fermi gas be directly described using these models? Are they the same thing?
i.e. If I wanted to decribe the difference between a fermi gas and a fermi liquid could I...
Hello.
Is there a way to calculate properties of a gas, given only it's composition?
I.e. let's say i want to know what would a planet look like with an atmosphere of a mix of 50% gaseous sulphur and 50% gaseous mercury, at 500*C and surface pressure of half that of Earth.
How would i go about...
Hey I've been thinking of this idea for a while,
If I had a small boat with a home made gas turbine engine on it to power it solely with thrust. If I put an afterburner on it and nozzle; and had a small intake for water that filtered out all of the crud. Would it be possible to generate more...
Suppose I have a cylinder of gas and at time t=0 I can turn on a strong vertical gravitational force. Let the force change quickly (but a time long compared the mean free path divided by the average gas particle velocity) to reach some constant maximum value F(z,t) = F_max. (This force can be...
I understand that gas flow through a circular tube or pipe will have some understandable effects... for example the pressure drops, and the maximum flow diminishes. I also know that turbulence and the tubing surface has an effect...
Without getting too specific, I just want to understand...
So I'm trying to figure out the average energy of diatomic gas molecules via the equipartition theorem at high temperature (such that it's translational , rotational and vibrational modes are activated)
and to do that I need to know the degree of freedom.
some websites claim it would be 6 , 3d...
Homework Statement
In an empty rubber raft the pressure is approximately constant. You push on a large air pump that pushes 1.0L (1.0×10^−3 m^3) of air into the raft. You exert a 16N force while pushing the pump handle 2.0×10^−2 m .
Part A: Determine the work done on the gas.
Part B: If all...
Homework Statement
In an ideal gas at temperature T, the average force that a molecule applies on the walls of a closed container depends on T as Tq. A good estimate for q is:
A. 2
B. 1
C. 1/2
D. 1/4
Homework Equations
PV= nRT
I think, Volume of container and moles are constant.
So P ∝ T
The...
Homework Statement
Consider ##n## moles of gas, initially confined within a volume ##V## and held at temperature ##T##. The gas is expanded to a total volume ##\alpha V##, where ##\alpha## is a constant, by a reversible isothermal expansion. Assume that the gas obeys the van der Waals equation...
Homework Statement
Given: Ideal gas equations:
Find S(T,V) for an ideal gas
Homework Equations
Ideal gas equations:
\begin{array}{l}
{\rm{}}\\
U = \frac{3}{2}N{k_B}{\left( {\frac{N}{V}} \right)^{2/3}}\exp \left[ {\frac{S}{{\left( {3/2} \right)N{k_B}}} - {s_0}} \right]{\rm{ }}\\
T = {\left(...
Homework Statement
Can someone confirm if I answered correctly? Thanks for support and help!
a) In the Brownian motion experiment, small particles of matter are seen moving randomly. Give an explanation for this motion.
b) Boyle's Law is fundamental when discussing the gas laws.
i) State...
Hello, I know this has been fairly discussed to death, but I've had relative trouble finding a response that specifically addresses the n, in PV= nRT, the ideal gas law.
Out of relatively common sense, by adding additional moles of gas, the pressure in the gas should increase as there are more...
Hello everyone! I am new here. I have used this forum on and off through google searches in the past and learned a fair bit from the posts. This is the first time asking anything.
The question is probably extremely simple but has been overrun in my head for a week! It is in regards to...
Hey guys
Don't know if this is posted in the right category.
doing an technical report on industrial gas turbines. but i am kind of lost. Does anyone have any input to what we can write about? I'm thinking of any problems with the turbines that we can write about.
What heat loss and how much...
Homework Statement
\rho_0, c_0 is the mean density, the mean speed of sound in the ideal gas.
Is the following correct?
c(\rho)=c_0\left(\frac{\rho}{\rho_0}\right)^{\frac{\kappa-1}{2}}
Homework Equations
p = const * \rho^\kappa, c=\sqrt{\frac{\partial p}{\partial \rho}}
The Attempt at...
Its given in my textbook that equivalence of gas = (volume of gas) / (Volume of 1 eq. gas at NTP)
How do i calculate volume occupied by 1 equivalent of gas?
Example: What would be the volume occupied by 1 eq. of CO2 (Its given 11.2l in my book)
Is there a formula for this?
Homework Statement
The cannon is made from V=30ml test tube completely closed with a plug (diameter d=1,5cm; length l=3cm; mass m=5g). Before closing the test tube, V'=1ml of water is poured into it. Room temperature is 20oC , pressure p=105 Pa , relative humidity is σ=20%. When the temperature...
Homework Statement
The cannon is made from V=30ml test tube completely closed with a plug (diameter d=1,5cm; length l=3cm; mass m=5g). Before closing the test tube, V'=1ml of water is poured into it. Room temperature is 20oC , pressure p=105 Pa , relative humidity is σ=20%. When the temperature...
Hi there,
I'm trying to clear up some misconceptions I have about emission spectra from various substances. Most of the discussion about gases focusses on the line emission spectra from a hot, low density gas due to electron shell transitions. But I also know that any charges that are made to...
F = Δp/Δt
http://www.sumoware.com/images/temp/xzhhjttxobbodxgr.png
(Sorry for bad sketch.. hehe)
In the kinetic-molecular theory of gas, the Δp is -2mv (since it's supposed to be elastic collision)
But, why the Δt is 2L/V ??
I think it must be a very small time (since the impact is done in a...
Homework Statement
Just want to check that I've used the correct method for this thermodynamics question I've been set. Any clarification would be greatly appreciated.
So I have 0.5kg of gas held in a rigid container of volume 0.25m^3 at a temperature of 20°C. 20kJ of heat energy is required...
In physics book, if work is done by the system, it is positive
in my chemistry book, if work is done by the system, it is taken as negetive.
when I asked my chemistry teacher, he said the sign convention is different in physics and chemistry.
but why are they different?
Really simple question but it's been making me a little confused.
Lets imagine we have a container (cubic with length of 1 meter) with a pressure of 1 Pascal and then an area inside the container of 1 mm^2 is chosen to measure the force on that area, what would the pressure be? 1 Pascal or...
Homework Statement
Estimate partial pressure of nitrogen in atm in a room where you are at this moment. Use an ideal gas approximation and assume that air is composed of only nitrogen and oxygen. Show how you arrive the final answer in detail.
Homework Equations
pv=RT, while p stands for...
Hi I was wondering if anyone could tell me what gasses are absorbed between 800 and 1000nm wavelength and weather there is a book that lists all the gas wavelengths that can be absorbed in this region
Thanks bertopolis
Hi
I am new member ( mechanical engineer student ) , and the college just add a new course which is
Turbo machinery , any way the teacher is new to the course & the quality of our teacher is not that
good so , I was having a question and ask him but didnt get much from him so here I am ^^When...
Here is a screenshot from a page from a textbook that explains how to derive the ideal gas law:
In the third bold line, I don't understand how "time" in force = (change of momentum)/(time) is equal to 2x/u (the time it takes for the particle to travel to the opposite face and back again) -- I...
Homework Statement
Derive an expression for the change in internal energy of 1 mol of an ideal gas for expansion from volume V_i to V_f under constant pressure of 1atm where \gamma = \frac{C_p}{C_v}=\frac{5}{3}
Homework Equations
\Delta U=\frac{3}{2}nR\Delta T
PV=nRT
The Attempt at a...
Homework Statement
At 1 atm and 0° C, a 5.04 L mixture of methane (CH4) and propane(C3H8) was burned producing 20.9 g of CO2. Assume complete combustion.
1. How many moles total of methane and propane were present before combustion?
2. How many moles of carbon dioxide were present after the...
Homework Statement
A blackbody photon gas is contained within an evacuated cavity (V = 0.01 m^3).
Calculate C_p for the photon gas at T = 1000K
Homework Equations
C_p - C_v = T(\frac{\partial S} {\partial V}) (\frac{\partial V}{\partial T})
C_v = T(\frac{\partial S} {\partial T})
S =...
Hi there,
I'm considering how the ideal gas law applies in practice in our planet's atmosphere. In particular, I'm considering this form of the law:
P = ρRT (1)
where P is pressure, ρ is density, R is the gas constant and T is the temperature.
I also know that, to a good approximation, the...
Greetings Everyone!
I read a very good thread regarding how Ideal Gas Law is used to calculate system work for the electrolysis of water:
W = PΔV = (101.3 x 103 Pa)(1.5 moles)(-22.4 x 10-3 m3/mol)(298K/273K) = -3715 J
https://www.physicsforums.com/threads/work-of-electrolysis-of-water.756240/...
Homework Statement
An air bubble of volume 3.0x10-5m3 escapes from a divers equipment at a depth of 45m where the water temperatures is 5 degrees C. What is its volume as it reaches the surface, where the temperature is 12 degrees C? Atmospheric pressure = 101kPa, density of sea water =...
Homework Statement
The volume of 30.0 moles of a monoatomic ideal gas is reduced at a uniform rate from 0.616m3 to 0.308m3 in 2h. Its temperature is increased at a uniform rate from 27.0◦C to 450◦C. The gas passes through thermodynamic equilibrium states throughout.
(a) Write down explicitly...
I believe I know the answer to this question; I need an expert to verify it for me.
I work for a company that makes latex balloons. The people that have been here for a long time insist that if one is putting a small (5" balloon) filled with helium inside a larger (30") balloon then one must...
Dear All,
I am a mechanical engineer who has recently started working in the oil& gas industry (compression). I would appreciate if someone can guide me to where can I learn about reciprocating compressors.
Much appreciated.
Homework Statement
A chemical reaction is described by the equation N2O4 <> 2NO2. The pressure equilibrium constant for the given reaction is equal to 8 Pa. Which picture describes the equilibrium? (Please, see the attached file!). [/B]Homework Equations
N2O4 <> 2NO2[/B]The Attempt at a...
Homework Statement
Let ##h## be the height above sea level. Show that the reduction in air pressure ##dp## as a function of ##dh## is given by ##\frac{dp}{p} = -\frac{Mg}{RT}dh##. Where ##M## is the molar mass of air and ##T## the temperature at height ##h##.
2. Solution
This problem got a...
Hi all, I have a question from a tutorial sheet that I'm stuck with. The question is
Estimate the pressure at which a gas of argon atoms, at a temperature of 300 K, will begin to show deviations from the ideal gas behaviour due to the finite size of the atoms. Answer: Of order 10^9 Pa.
So I...
This is health&safety related question that came out of a discussion I had with a friend.
I sometimes keep a large (L sized) helium cylinder in my lab. It is pressurized to 200 Bar and equipped with a standard regulator.
Now, the question is what would happen if it fell over and the...
So basically I was wondering whether it's possible to get the expression of ideal gas using molecular flux equation which is ##\phi = \frac{1}{4}\bar{v}n##. The derivation should be straightforward. I need to get the expression of pressure. Because the flux by definition already gives the rate...
Homework Statement
5 lbs of nitroglycerin detonates. What is the total volume of the gases produced? Homework Equations
PV=nRT
The Attempt at a Solution
I used the balance chemical equation of the decomposition of nitroglycerin and used stoichiometry to find the number of moles of nitrogen...
Homework Statement
(problem won't be word for word, because much of the info. is to throw people off); This large gummy bear, which contains 51 servings and each serving contains 29 grams of carbs. Assuming all the carbs are glucose, how many liters of CO2 would eating this gummy bear cause...
Homework Statement
Tums react in your stomach to produce a gas. The average adult stomach expand to one liter when full. Calculate the pressure in the average adult stomach after taking 2 Tums.
Homework Equations
Since its asking for pressure, and the volume is given perhaps PV=nRT should be...