Gas Definition and 1000 Threads

  1. N

    Installing Chemical Storage Tank: Pressure of Liquid or Gas?

    Hello Forum, I'm looking to install a new chemical storage tank at my site. The tank itself is not rated for vacuum. We will have proper ventilation and nitrogen pumping into the tank to compensate when we are pumping out of the bottom. However, I do want to include a pressure transmitter on...
  2. RJLiberator

    Thermodynamics of a Constant Volume Gas Thermometer

    Homework Statement A constant volume gas thermometer contains a gas whose equation of state is (p+\frac{a}{V^2_m})(V_m-b)=RT and another, of identical construction, contains a different gas which obeys the ideal gas law, pV_m = RT. The thermometers are calibrated at the ice and steam points...
  3. L

    Is average time between and after collision same for a gas?

    I am stuck on this concept in my physics book where the author claims that in a low density ionic gas the average of the time between collision and average of the time taken from last collision in ions is same. He further states that the average time to the next collision is same as the average...
  4. E

    Internal energy of an ideal gas as a function of temperature

    Homework Statement Two containers hold an ideal gas at the same temperature and pressure. Both containers hold the same type of gas but container B has twice the volume of container A. The internal energy of the gas in container B is (a) twice that for container A (b) the same as that for...
  5. S

    I Ammonia in icy moons of gas giants

    Its generally a established that ammonia is present under the ice of many moons of gas giants. I guess many in the astronomy/astrobiologists community don't spend much time at home, as they would have noticed that ammonia is a household disinfectant. I understand we don't have any idea of the...
  6. Vivek98phyboy

    Gas Through Porous Plug: Pressure & Temp Change Explained

    I can't understand why a gas passing through a porous plug experiences change in its pressure and why does the cooling or heating process depends upon the initial temperature
  7. T

    Compressing a gas above compressor's discharge pressure

    A 2 stage compressor has a final delivery/discharge pressure of 250 bar. hydrogen is been compressed and stored in vessels. The pressure in the storage vessel reaches the delivery pressure(i.e.250 bar) and the compressor is still running ( vessel has a safety pressure of 450 bar) and the...
  8. Const@ntine

    Ar (Gas) goes into spinner (Adiabatic Decompression): Power?

    Homework Statement Argo, in its gas form, is insterted into a spinner, with a rhythm of 80.0 kg/min = 1.33 kg/s, temperature 800 C (= 1073.15 K), and pressure 1.50 MPa. It's decompressed adiabatically, and "escapes" the spinner with pressure 300 kPa. a) Temperature when it "escapes" ? b)...
  9. D

    Why Does the Compressibility of Helium Gas Diverge in This System?

    Homework Statement A cylinder is fitted with a piston, and the cylinder contains helium gas. The sides of the cylinder are adiabatic, impermeable, and rigid, but the bottom of the cylinder is thermally conductive, permeable to helium, and rigid. Through this permeable wall the system is in...
  10. Const@ntine

    Molecular Specific Heat of an Ideal Gas: Computations

    Homework Statement A cylinder with a heavy ram/piston contains air at T = 300 K. Pi = 2.00 * 105 Pa, Vi = 0.350 m3, Mr = 28.9 g/mol & Cv = 5R/2 (a) What's the Molecular Specific Heat of an Ideal Gas, with a constant volume, computed at J/KgC ? (Cv) (b) What's the mass of the air inside the...
  11. M

    EGR ratio from exhaust gas composition

    Homework Statement given:-fuel and air mass flow, measured mole ratios of exhaust composition y_i. Let's assume stoichiometric combustion so we have only CO2, H20 and N2 as products. Homework Equations Can EGR ratio be calculated from available data? The Attempt at a Solution I get result...
  12. E

    Calculate Pressure Drop through Expansion/Reduction for Gas

    Something that routinely comes up as a problem at work is when we size flow projects for piping systems. We calculate pressure drop across a length of fixed diameter for compressible gasses, but we do not calculate pressure changes through an expansion or contraction with gas (for example...
  13. Misha Kuznetsov

    I Possible to Store Energy in Ionized Gas?

    How plausible would it be to store energy in the form of ionized gas? The idea is that a gas (I am assuming a noble gas would work best) would be ionized so that some outer electrons are removed from the atoms and then a positively charged Van de Graaff generator (or something that can fulfill...
  14. PainterGuy

    Pressure exerted by an ideal gas

    Hi Please have a look on the attachment. Suppose that a 0.1 kg rubber ball having velocity of 60 m/s is moving between two walls A and B, and the distance between the walls is 1 m. It is having elastic collisions with the walls. Let's focus on what is happening at wall B. The ball is moving...
  15. R

    Acceleration of a gas into a vacuum

    Set up: Gas on one side of a divider and an infinite vacuum on the other. Question: When you remove the divider, over time, does the gas increase in acceleration, does it peak and then decrease or does it remain the same as the gas enters the vacuum/ leaves the side opposite the vacuum?f Thanks
  16. R

    Estimate average speed of electrons in gas?

    Homework Statement Suppose that a heated gas comprised of electrons glows bright orange when it is in use. Estimate the average speed of the electrons in the gas. Model this gas as an ideal gas. Homework Equations None. I have no clue. This is a "review" question on a chapter titled "Current...
  17. A

    Statistical Physics: Quantum ideal gas

    Homework Statement I'm reading the book about Statistical Physics from W. Nolting, specifically the chapter about quantum gas. In the case of a classical ideal gas, we can get the state functions with the partition functions of the three ensembles (microcanonical, canonical and grand...
  18. A

    B Gas Behaviour in Space: Exploring the Mysteries of Gaseous Matter Beyond Earth

    What happens to gases in space? Do they just dissapear? (Yes yes, yawn) Or can they make up a region of space, and stick together via gravity? And what about Jupiter and other gas giants? How do they work, if in space, all gases tend to just shoot out and spread into an even film?
  19. U

    Pressure dependence of the equilibrium constant for an ideal gas

    I read in some scripts that equilibrium constant for an ideal gas is not a function of pressure: But that is not generally true! Since: $$\left (\frac{\partial \Delta_{R} G}{\partial p} \right )_{T,\vec{n}}=\Delta_{R} V$$ and $$\Delta_{R} G^{0}=-RT\cdot \ln K$$ it should be: $$\left...
  20. B

    B Internal energy of compressed gas

    Hi, I've been reading about compressed air energy storage and keep coming across that in 300 bar containers the achievable energy is 0.1MJ/L. Is this 0.1MJ/L of the volume of the air it is compressed to or of the total L of air that was initially used? (E.g If 1500L is compressed to 300 bar...
  21. eigenmax

    Need a small valve for gas injection? Any ideas?

    Hello everyone, For injecting gas into a little setup I've got, I have the following mechanism set out. The gas comes from a chemical reaction, goes through a copper capillary, then to a glass tube which was melted in the centre and pulled at both ends to create a thin passage. Then from that to...
  22. K

    What is the Relationship Between Gas Pressure and Fluid Column Height?

    Homework Statement I need to find the amount of H2 being lost to water by being stored underneath a column of water. About 16 mL of H2 is made and it displaces the column by 16 cm. However the total amount of water is 30 ml/30 cm. I'm not sure which relationship to use to find the pressure of...
  23. M

    How Does Box Size Affect Kinetic Energy Calculations in Gas Molecules?

    In definition and proof of kinetic energy, it uses the second law of Newton. The length of the box is L and it uses this length to define the time of applying the force on the wall. Actually this time should be only time that molecule reaches to the wall and changes its velocity. My question...
  24. chopnhack

    Gas at a constant pressure: using Cv.dT correctly

    Hello, my questions is not so much homework, but a request for a definition. When we use Cv*dT to solve for dU (internal energy) in a constant pressure example, what is the order of the temperatures entered into dT? Is one to assume its final temp minus initial temp? I ask because it leads to...
  25. chopnhack

    PV Diagram of Ideal Monatomic Gas Processes

    Homework Statement 1.0 mol sample of an ideal monatomic gas originally at a pressure of 1 atm undergoes a 3-step process as follows: It expands adiabatically from T1 = 588 K to T2 = 389 K It is compressed at constant pressure until its...
  26. F

    Does Rotating a Gas Container Increase Its Temperature?

    If I place an insulated container of gas on the edge of a turntable and then rotate the container as a constant angular velocity, what happens to the gas? Does the temperature of the gas increase? If so, how was work done on the gas?
  27. C

    Quick question about perfect gas

    Two different gasses (Helium and Cripton) are mixed up. We can assume the compound behaves as a perfect gas only if the atoms of He and Kr have the same average value of: Mass Momentum Velocity Kinetic energy Which one is correct? I can't figure it out.
  28. Z

    A Gas diffusion through a semi permeable membrane

    Say I have a small solid polymer container filled with gas A. The walls of the container are semi-permeable, so gas A on inside can't get through/out. On the outside, gas B at atmospheric pressure, which can migrate through the membranes of container. Pressure inside the container is 0,6 bar...
  29. SciencyBoi

    Internal Energy of an Ideal gas related to Molar specific heat

    Homework Statement Please look at the below images which is the derivation of the relation between the internal energy of an ideal gas and the molar specific heat at constant volume. (Snaps taken from Fundamentals of Physics Textbook by David Halliday, Jearl Walker, and Robert Resnick) As...
  30. Pat Bannan

    Gas under pressure- disturbing noise recurring

    recently my neighbors and I have been awakened by a loud noise that sounds like something is being released under high pressure. An intense vibrating sound that lasts 30-45 seconds. We live across the steet from a soda manufacturer and down the road from a natural Gas transfer station. Both are...
  31. H

    How to find added thermal heat in monoatomic gas?

    Homework Statement for number 3,4,5 I'm still tryingHomework Equations PV/T = PV/T q = ΔU + W W = P ΔV The Attempt at a Solution (3) I used PV/T = PV/T to find the ΔT for each process for A→B I find PV/TA = P3V/TB ----- TB = 3TA (T increase) for B→C I find P3V/TB = 4P3V/TC ----- TC =...
  32. P

    Ideal Gas Law -- Isobaric Epansion followed by....

    Homework Statement An ideal gas with Cv = 5/2R, and γ = 1.4 starts at a volume of 1.5m3 , a pressure of 2.0×105Pa, and a temperature of 300K. It undergoes an isobaric expansion until the volume is V , then undergoes an adiabatic expansion until the volume is 6.0m3 , and finally undergoes an...
  33. szopaw

    Final velocity of an air rifle pellet from compressed gas

    As in the title, I'm trying to establish the approximate velocity (sans friction and other losses) of a pellet propelled by compressed gas from a tank. Below is what I have came up with myself, I would appreciate if someone could review this as say whether the end values are reasonable. I have...
  34. F

    What caused the change in a pilot light at my workplace?

    This has been bugging me for a few months now, and I'm hoping that someone can provide me with an answer. A while ago, my colleague was soldering with an oxy-acetylene torch and paused for a few moments in between jobs, leaving only the pilot light on top of the unit burning. Sitting about 4-5...
  35. B

    Equation of states for a gas that forms dimers

    Homework Statement Show that to a first approximation the equation of state of a gas that dimerizes to a small extent is given by, ##\dfrac{PV}{RT} = 1 - \dfrac{K_c}{V}## Where ##K_c## is equilibrium constant for ##A + A \iff A_2## Homework EquationsThe Attempt at a Solution Using virial...
  36. A

    How mass flow and pressure ratio is related in case of a Gas Turbine

    Hi, As per my observation and experience, when we use evaporative cooler to cool the inlet air to the gas turbine, the compressor discharge pressure (i.e PCD or P3) rises. As, the temp. of the inlet air drops and the mass flow increases due to the increase in density, I believe the discharge...
  37. PHstud

    Liquid to gas expansion temperature change in a tank

    Hello ! I have troube doing a calculation. Let's say we have a volume Vi in a tank at a pressure Pi. If I let my tank open, the tank's liquid will start to boil to keep the pressure Pi inside the tank. Now, at the end, I will have a volume Vf in the tank, and still a pressure Pi. But the...
  38. G

    What is the power of a car engine?

    Homework Statement The volume displacement in a car engine is 2000 cm3. During the power stroke, the mean pressure inside the cylinder is 15 bar. Compute the work performed by the engine in one revolution. Compute the engine's power assuming it runs at 3000 rpm. Homework Equations...
  39. BillTre

    New Concept for Zero Emission Natural Gas Power Generation

    Science mag news article on a new electrical power plant being set-up by a start-up. It burns natural gas with pure oxygen and runs turbines with CO2. It makes water rather than using it and is in theory close to competitive economically. . Sounds good to me, but I'm no engineer.
  40. B

    Compressing Gas: Work Done Calculation

    Homework Statement [/B] A closed cylinder with a piston is used to compress gas that is initially at 1bar and temperature 293K. The compression is performed adiabatically until the volume is 1m3 and the pressure is 10bar, calculate the work done. Homework Equations [/B] pV = nR0T - ideal gas...
  41. H Psi equal E Psi

    Ideal gas pressure from Maxwell-Boltzmann distribution

    Hi everyone I'm having trouble with solving an exercise in statistical physics. I need to argue why the average number of particles with a velocity between ##v## and ##v+dv## that hit a surface area ##A## on the container wall in a time interval ##\Delta t## is $$N_{collision}=v_{x}A\Delta t...
  42. M

    Mass Flow Rate of Flue Gas in Sugar Industry

    Hello, I want to find the mass flow rate of flue gas, i have only the diameter of pipe and ID fan speed which are 1.48Meter and 980 RPM respectively
  43. DevonZA

    Change of internal energy of an ideal gas

    Homework Statement Homework Equations Δu = ∫ [(a-Ru)+bT+cT^2+dT^3]dT The Attempt at a Solution The answer of 6447kJ/kmol is given but I am struggling to get to this answer after integrating the above formula and inserting the given values. Firstly would the integral of...
  44. J

    Trying to build a gas collecting chamber above a packed bed

    Hi guys, I'm a graduate student and currently doing some research on a packed bed - I want to collect gas data from the headspace of my samples so i thought of building a gas collecting chamber on top of the vessel, where i can take gas measurements using calorimetric gas tubes. I'm not sure...
  45. A

    About filled gas inside a Geiger Muller meter

    Hi, I have a dumb question about the filled gas inside a Geiger Muller meter. I know it is considered as a gas detector. It requires a filled and quench gas for the probe. My question is: where does the gas get injected into for like a pancake probe. (Let's use Ludlum Model: 44-9 as example)...
  46. R

    Partition function for ideal gas for "medium" temperature

    Looking for the heat capacity of ideal gas due to rotational degrees of freedom. If the temperature of the gas is much higher than the temperature corresponding to the energy differential between states,the partition function can be written as the integral over the density of states. If the...
  47. ervays

    What's inside a gas detection Station?

    Good Morning guys! I'm trying to understand more about gas sensors. I know a lot about electrochemical and metaloxide sensors. I've faced all the limits that those sensors presents when you are using them outdoors. Now I'm wondering how the gas sensors stations can measure different gases...
  48. knc

    What is the Work Done by a Gas in a Cycle?

    Homework Statement Homework Equations PV = nRT \\ W = - \int_{V_i}^{V_f} P dV \Delta E_{int} = Q + W The Attempt at a Solution a)[/B] Since this is a cyclic process, the change in internal energy of the system is 0. \Delta E_{int} = 0 The process causes some ice to melt, meaning heat...
  49. Jason Louison

    Automotive Exhaust Gas Pressure/Blowdown Calculations

    Hi! I am a bit confuzzled by these equations given by a highly referenced and cited paper I have been using to create a spreadsheet I have been working on. The equations are: PV=mRT Where P is the cylinder pressure, m is the mass of gasses in the cylinder, R universal gas constant of the gas...
  50. F

    Theory behind gas tubes in lab experiments

    For chemical experiments that involve gases as reactant and products, gas tube are used for their transport. Q1. Why are there differences in length of gas tube when in a round flask. In most case, entering tubes are longer than exiting tubes? Why is that? Q2. Why is sometimes the entering...
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