Gas Definition and 1000 Threads

  1. Baluncore

    Can Lead Acid Batteries and Sea Water Create Chlorine Gas in Submarines?

    Submarines that had lead acid batteries and were depth charged during WW1 or WW2 sometimes produced chlorine gas inside the submarine. Was that because; 1. Broken batteries leaked sulphuric acid into the bilges where sea water with NaCl had accumulated, or; 2. Leaking seawater flooded the...
  2. E

    Small pipe break for an ideal gas

    Homework Statement A large tube filled with an ideal gas at pressure p1 and temperature T1 has a small break in it towards an envirronement at p2, with p1 much larger than p2. What is the flow rate through the hole to the outside of the tube. Homework Equations pv=rT Δh+Δc2/2=δq-δl h1 + c12 =...
  3. S

    Pressure -- non-compressed gas through an orifice

    I have 1/4" diameter tubing (tightest point prior to valve) leading to a solenoid valve with a 2.5 mm orifice. I am trying to compute how much pressure it would take to move 1 and 2 CFM of 190C air through the valve (to atmosphere). I am using blowers and I don't know if they will be able to...
  4. B

    Ideal gas through Isobaric process

    Homework Statement This is probably a real easy task for most, but I simply CANNOT manage to calculate it, even given the correct answer. I will translate it as best I can and hope I don't phrase it in a way that causes misunderstandings: 12 Moles of an ideal gas go through an Isobaric...
  5. O

    B Hello all, lay-man's question about gas laws

    Hello all, I have perused this forum for a while now. I've never signed up because I have nothing to offer you folks. I'm not evan an amateur, I'm just interested in physics. I'm a critical care / flight medic, so my understanding of physics is really, really, really limited. Although, I'm...
  6. Tardis Traveller

    Ideal Gas Expansion: Finding Depth of Tank

    Homework Statement A bubble comes from the bottom of the tank of water to the surface and triples in its volume. If the temperature of the tank of water doesn't deppend on the depth what is the depth of the tank that the bubble was at? Homework Equations ##PV=nRT## The Attempt at a Solution...
  7. A

    Is concentrated HCl (12M) a liquid and a gas?

    I just remembered that in my lab from a few months ago, the 12M HCl we used was "evaporating" or producing gas, similar to dry ice in water but no where near as much vapor. I'm just curious, is concentrated HCl usually like that or was the acid contaminated?
  8. Seth Allen

    Other Gas Turbine Tuning and Control Job - How & Where

    Hello all! I am going out on a limb here looking for information as I am unable to find the answers scouring the internet. Essentially I want to know how a person would go about getting a job working with Gas Turbine Tuning and Controls? I've got an engineering background, lots of gas turbine...
  9. M

    Temperature & kinetic energy of particles in solid vs gas

    Consider the internal energy of a gas and solid (different materials) both at the same temperature, which material has the larger potential energy and why? Do they also both have the same kinetic energy? Finally is the definition of temperature as the average kinetic energy of the particles only...
  10. R

    Total energy of free electron gas

    Hello everyone! I encountered a problem about the specific heat of electronic gas and I do not understand a formula... so the problem says that experimentally it has been shown that the specific heat of the conduction electrons at constant volume in metals depends on...
  11. P

    How to Calculate Gas Usage in Pressure Drop Situation?

    Homework Statement Pressure drops in welders tank of oxygen gas from p1=150atm to p2=120atm . How much of the gas will be used ? Homework Equations The Attempt at a Solution In my mind the simplest way of looking at this problem is to consider the process isothermal. But then the volume of...
  12. S

    I Difference between solid-state, semiconductor and gas lasers

    What is the difference between solid-state (SS), semiconductor and gas lasers? I know SS lasers are optically pumped (generally), while semiconductor and gas lasers are electrically pumped (laser diode). The active mediums are also unique. Beyond this though, I'm not entirely sure about any...
  13. P

    Ball of gas experiences rapid increase in pressure....

    Homework Statement A self-gravitating ball of gas suddenly experiences a rapid increase in its pressure to a new value P'. Taking average density of the star to be ρ and radius R, and ignoring gravity altogether, estimate the time scale of expansion of the star. Homework Equations Force=...
  14. I

    How does the change in area affect the velocity of helium gas in a vacuum?

    Hello here is a schematic of the problem: http://imgur.com/CgcybVT A stream of helium gas will be used to carry aerosolized particles. I am assuming conservation of mass (and mass flow) The mission is to find the exit stream velocity of the gas. For the time being, i am assuming the weight...
  15. James Ray

    Work done on ideal monatomic gas in adiabatic process

    1. The problem statement, all variables and given/known data Homework Equations [/B] The Attempt at a Solution [/B]
  16. James Ray

    Solve Ideal Gas Problem: Gamma = 1.4, VA=4.33m^3, PA

    Homework Statement A gas undergoes a cyclic process as shown in the figure above. The gas has gamma = 1.4. In the diagram A has volume V_A = 4.33 m^3, pressure P_A Homework Equations The Attempt at a Solution [/B]
  17. C

    B Why is the noble gas configuration inert?

    Walther Kossel and Gilbert Lewis: "During the formation of a chemical bond, atoms combine together by gaining, losing or sharing electrons in such a way that they acquire nearest noble gas configuration." By what understanding I have so far, and do correct me if I'm wrong, atoms tend to attain...
  18. M

    I Ideal Gas Law - Real Life Question?

    Hi Guys and Gals, As I was pumping up a flat bike tyre, a weird thought occurred to me about the application of the ideal gas law. Once the tyre essentially finds its physical dimension limitations (i.e. is shaped like a bike tyre and no longer changing shapes) and starts putting in reasonable...
  19. adriplay

    How to Determine Heat Capacity in a Hard-Sphere Gas Simulation?

    I have a simulation with a bunch of particles with volume bouncing around in a box with no interaction between them, a hard-sphere gas. Initially, they all have the same momentum |p|=√(2⋅m⋅2/3⋅k⋅T) to have the average kinetic energy 3/2⋅k⋅T. I'm asked to add a constant energy flux to the system...
  20. Ecthe

    I Calculating gas flow trough a pipe and a nozzle

    Hello there. I am struggling with some gas flow calculations that, I think, should be quite basic. However, I think that I miss the knowledge background for it. I have a setup that I am showing in the attached file but here are more details: -I have a vacuum chamber pumped with a turbo pump to...
  21. A

    What are the properties of lithium gas?

    I know this may be a dumb question but I don't know it. What I want to know is when lithium is heat and becomes a gas/vapor, does it still have the properties of lithium. Also I know that when water is changed between a liquid, gas, and solid, it always stays as H2O on the molecular level, can...
  22. I

    B Finding a Gas for Physics Experiment

    Hello I am currently performing an interesting physics experiment and am in need of a gas that is easily accessible and can easily be ionized by someone with basic equipment. Any help would be greatly appreciated.
  23. S

    How Does Intermolecular Potential Energy Behave in Ideal and Real Gases?

    Homework Statement In the kinetic model of an ideal gas, it is assumed that: A. The forces between the gas and the container are zero B. The intermolecular potential energy of the molecules of the gas is constant. C. The kinetic energy of a given gas molecule is constant D. The momentum of a...
  24. T

    Lowest Kinematic Viscosity Fluid - High Pressure Gas

    I am trying to determine which fluid to use in an experiment. An important aspect of the experiment is the ratio of inertial forces (due to mass) vs the viscous forces that the fluid will experience Amongst common liquids the lowest I can see is Acetone with a kinematic viscosity of 0.41 cSt...
  25. N

    Entropy of mixing - Ideal gas. What is x?

    Homework Statement A bottle with volume v containing 1 mole of argon is next to a bottle of volume v with 1 mole of xenon. both are connected with a pipe and tap and are same temp and pressure. the tap is opened and they are allowed to mix. What is the total entropy change of the system? Once...
  26. C

    What is the Final Temperature of Methane Gas After Adiabatic Expansion?

    Methane gas at 550K, 5 bar is expanded adiabatically and reversibly to 1 bar. Find the final temperature of the gas. I have made little progress with this... I've calculated the initial volume, and that is all so far. Obviously to find the work usually I'd integrate pressure with respect to...
  27. M

    How to do failure analysis of gas turbine blade ?

    I want do thermal and structural analysis (Failure) on gas turbine blade. So what how to begin. Kindly help me.
  28. B

    Gas and liquid flow rates in Gas-liquid flow loop

    Homework Statement I'm working on my research project at uni, running a gas-liquid flow loop for horizontal stratified flow exhibiting wave propagation. The equipment I have however is setup to investigate vertical flow primarily and the flow meters are located on the vertical sections. I need...
  29. Paul Colby

    A Why are low pressure gas discharge lamps thermal sources?

    When an atom makes a single photon transition it adds a single photon to the radiation field. One might then expect that a low pressure gas discharge would emit photons in Fock states? How is it that photon of an atomic spectral line produced in a low pressure gas discharge become thermalized?
  30. T

    Rotational Inertia Gas vs Liquid

    I am conducting an experiment that rotates a sealed donut cylinder to investigate amongst other things the inertia of the contained fluid. Process I rotate the cylinder to a set speed (assuming that the viscosity of the internal fluid will end up rotating the fluid to solid body rotation) then...
  31. R

    I Differential number of particles in Fermi gas model

    I'm practicing for the Physics GRE, and came across a question that has me stumped. "In elementary nuclear physics, we learn about the Fermi gas model of the nucleus. The Fermi energy for normal nuclear density (ρ0) is 38.4 MeV. Suppose that the nucleus is compressed, for example in a heavy ion...
  32. toforfiltum

    Effect of density on rms speed in ideal gas eqn

    Homework Statement Homework Equations 1) PV = nRT 2 )## P = ⅓ ρ<c^2> ## 3) KE ∝ T The Attempt at a Solution According to the second equation above, density is inversely proportional to root mean square speed at constant pressure, but the answer states that the root mean square speed depends...
  33. Allen_Wolf

    B Gas Giants & Stars: Do They Have a Solid Part?

    Are the gas giants and stars only composed of gas particles? Don't they have a solid crust or something? If they don't have a solid part then how can they exist alone?
  34. gonadas91

    I Does the Equal A Priori Probabilities Assumption Hold for Interacting Gases?

    Hi! My question has to be with the equal a priori probabilities assumption in the microcanonical ensemble when we consider an interacting system, that is, particles interacting between them but no external work or heat is done over the system. Does this assumption still hold for such a system...
  35. R

    Resistance between 2 points in infinite 3-D gas volume

    Hi Back in 2011 here https://www.physicsforums.com/threads/resistance-between-two-points-in-an-infinite-volume-of-resistive-gas.513388/ the question of the resistance between two points in an infinite volume of resistive gas was raised but petered out without a solution. The solution could be...
  36. toforfiltum

    Why is there no work done on gas from Q to R?

    Homework Statement [/B] Homework Equations U = Q + W The Attempt at a Solution I don't understand why there is no work done on gas from Q to R. I thought that work done on gas = pv? If so, then why there is no work done on gas because there is increase in pressure? So, I tried to find a...
  37. I

    Gas Turbine TS Cycle: Understanding the Significance of Points 5-5b and 5b-6

    Homework Statement Homework Equations N/A The Attempt at a Solution I am confused what 5-5b and 5b-6 represent in the above TS diagram. I know that 1-2 is compression, 2-3 is cooling, 3-4 is compression and 4-5 is regeneration (since these are indicated in the block diagram) but as for 5-5b...
  38. marsten

    Calculating Flue Gas Enthalphy kJ/kg - Marcus

    Hi 1. Homework Statement I'm trying to calculate the enthalphy of flue gas leaving a gas turbine, in kJ/kg. I just want to confirm that I'm using a correct method. Homework Equations hfg = (VCO2⋅ hCO2 + VH2O⋅ hH2O + VN2⋅ hN2 + VO2⋅ hO2) / (VCO2 + VH2O + VN2 + VO2) ρfg = (p⋅ M) / (R⋅ Tfg)...
  39. E

    Gases that absorb IR radiation

    Hello, I'm looking for a gas (hopefully one that is readily available) that will absorb Nd:YAG laser radiation at 1064 nm. The purpose is to heat the gas to transmit heat into a glass fiber composite which normally does not absorb IR light.
  40. Dr. Manoj

    Why Can't Scuba Kits Be Filled with Only Oxygen?

    I read in my textbook that Scuba kit has mixture of air such as nitrogen hydrogen and oxygen sometimes even helium is used instead of nitrogen. As pressure increases going deep in oceans, solubility of gas in liquid increases. So oxygen starts to dissolve quickly. But I don't understand why...
  41. F

    Gas pressures with (hypothetical) filter

    Imagine I have 2 constant-volume, constant-temperature containers. Container A has a volume of 10 L and one Container B has a volume of 5 L. My hypothetical gases Ideal Gas A and Ideal Gas B have the same properties as each other (temperature, mass, energy, heat capacity, blah blah blah). If I...
  42. C

    Determining How Long My Gas Cylinder Will Last

    I'm not sure whether this is the correct place to post but here goes :wink: I'm trying to determine how long my argon gas cylinder will last when I am using it for tig welding. The cylinder is supplied with 1.32m³ (1320L) of Argon at 137 bar (13.7 MPa). If I set my regulator pressure to 0.5...
  43. M

    Find Heat Energy Needed to Expand Gas to Triple Volume

    Homework Statement When 0.40 mol of oxygen(O2) gas is heated at constant pressure starting at 0 degrees C, how much energy must be added to the gas as heat to triple its volume? (The molecules rotate but do not oscillate) Homework Equations pV=nRT p1V1/T1=p2V2/T2 Q=mcdT Value of Cp for Oxygen...
  44. dgd87

    How Much Gas Can Be Injected in a Rotative Gas Lift System?

    Hi Everyone, I work with rotative gas lift systems, sizing the compressors (recip´s), I'm not that familiar with the oil well, though. I have a doubt regarding the gas flow going to the well. There is a new well which currently produces 0.4 MMscfd of gas and the client wants the system to be...
  45. M

    Atomic Conservation in Ionized Hydrogen Gas

    Dear all, So I have a question concerning atomic conservation in an ionized hydrogen gas. So imagine we have ## H_2 ## initially. Later the gas is taken to an appreciable temperature such that at equilibrium the following species are present, ## e^-, \ H, \ H^+, \ H_2, \ H^-, \ \text{and} \...
  46. M

    I Internal energy of an ideal gas -- confusion

    We know that internal energy of ideal gas depends only on temperature. Let's say we have 1 mole of ideal gas with pressure P1, volume V1 and temperature T. Let's call this the state 1. Equation of state for ideal gas applies: PV=RT. Now if we expand (or compress gas) isothermally, gas will then...
  47. henrco

    Ideal Gas compressed at constant pressure

    Hi, Could I please get some guidance on my approach and solution, for this particular problem. Any assistance welcome. 1. Homework Statement An ideal gas is compressed at a constant pressure of 1.3 atm from a volume of 20 L to 12 L. During this process it gives off 3.69 kJ of heat. What is...
  48. Ethan Godden

    An ideal gas going through a cycle

    Homework Statement The problem is attached Homework Equations ΔEint=Q+W W=-PΔV The Attempt at a Solution Attempted solution is in the attachment. The problem is I am not getting the same answer as the supposed correct answer. Thank You, Ethan
  49. y2j

    Automotive Temperature and mass flow rate of ICE exhaust gas

    Hi everyone I searched about the mass flow rates and temperatures of exhaust gases of light gasoline internal combustion engine at different condition but I don't fond anything yet . Anyone can guide me? .
  50. D

    Thermodynamics First law ideal gas question

    Homework Statement We have 0.0008 Kmol of an ideal gas are expanded from V1 to V2 v2=3V1 process is reversible and T/V=Constant if the work obtained by this expansion is 9.4 KJ find the initial temperature R=8.314 KJ Kmol-1 Homework Equations PV=nRT possibly T/V = T/V The Attempt at a...
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