Gas Definition and 1000 Threads

  1. C

    Gas chromatography question -- instrument not turning back on....

    My gas chromatography instrument ran out of air while cooling down and now it won't turn on, nor the computer it is hooked up to? Can this be fixed?
  2. B

    Confused - Pressure in a canister?

    A manufacturer quotes a standard CO2 canister contains 16g of CO2 at a volume of 20cm^3. So I need to calculate the pressure in the canister... Using ideal gas law P = nRT/V n = 0.364mol (16 of co2) R = 8.314 J/Kmol (universal gas constant) T = 294k (gas is at room temp 21 deg C) V = 20cm3...
  3. R

    Does 1 mole of all gas exert equal pressure

    1 mole of all gas has equal number of molecules irrespective of their size. So I just wanted to know when 1 mole of molecules exerts pressure on the wall of a container, will it be same for all gases, irrespective of their molecules sizes.
  4. P

    Does Entropy Change When a Gas Cylinder is Raised to Vertical?

    Homework Statement A thin, closed, insulated cylinder of length L, filled with ideal gas (temperature T, mass M, total amount 1 mole) lies on a table. It is very gently raised to the vertical, after which equilibrium is reestablished. Does the entropy change? What is the temperature change (to...
  5. R

    What Happens When You Dissolve a Gas in Water?

    I have a few simple questions about the process of dissolving a gas in water, if anyone could give me any help it would be appreciated. 1. How do I know the gas has dissolved? i.e. if I "bubble" gas into the liquid how do I know it hasn't just "bubbled" out? Or would this only occur once the...
  6. G

    Work needed to expand a very heavy gas under high pressure

    Hi there, not sure if this is the right sub-forum. I hope so. 1. Homework Statement This is the known data: A isothermal process in the ascending conduit (like a chimney) of a closed-loop circuit, which is thermally insulated from the atmosphere, and in no contact with the air. This is the...
  7. A

    Temperature in Constant volume gas thermometer.

    In the constant volume gas thermometer, T (°c)=[P(T)-P(f)]×100/[P(b)-P(f)] (P(T) means gas pressure at T°c P(b) and P(f) for the water's boiling point and freezing point) Is it right?
  8. 0

    Ideal Gas Law Equilibrium Requirements

    It is well known that the ideal gas law applies only to an ideal gas, one consisting of particles infinitesimal in size and exhibits no interactions between the particles. Considering an ideal gas, is the ideal gas law valid under non-equilibrium conditions? For example, does the ideal gas law...
  9. HelloCthulhu

    Temperature of gas during water electrolysis

    I know I can use the specific heat capacity formula to find the temperature of the water during electrolysis as long as I know the mass, specific heat constant of water and joules added beforehand: But I'm not sure how I could find the temperature of the gas produced. If the pressure was...
  10. Tam Le

    Is Water Vapor the Gaseous State of Liquid Water?

    Is it simply the gaseous state of a liquid substance? For instance, water vapor, in this context, would be the gas state of water after having transitioned from a liquid state.
  11. Z

    Can a Steel Vessel Contain Liquid Hydrogen at 15,000 PSI and 25C?

    I've read a fews post about liquid hydrogen boil off, but could use a bit more clarification; insight on the following thought experiment would be really helpful: What happens if I take a 1 L steel vessel, put 1 L of liquid H2 into it, seal it off, and let it sit in a room at 25C? The density...
  12. @PinkGeology

    Ideal gas law: can you use it to find P during exsolution?

    If you shake up a bottle of soda and it gets slightly larger because the disturbed gas in solution is trying to expand but cannot, could you use the difference in (THE SMALL AMOUNT THE BOTTLE ACTUALLY SWELLED) and the (POTENTIAL AMOUNT THE GAS WOULD SWELL IF NOT CONTAINED) to determine the...
  13. K

    How Much Nitrogen Gas and Pressure Are Needed for a 250°C Temperature Gauge?

    Hi, I Have one Temperature gauge with 2Meter Cpillary. Range is 0-250Deg Centigarde. it was field with Nitrogen gas immersion length (sensing element) was 100mm in the process. How much gas should field to get the 250Deg Centigarde temperature. and how much pressure is required to field the...
  14. B

    Can a Leaking Argon Gas Line Draw in Air and Create a Mixture?

    I have an argon line used for atomization and backfilling a VIM melting chamber. If there is a leak on the argon line (at a fitting, valve, etc), will this leak actually draw in air when gas is turned on and flowing through pipe creating a mixture of argon and air?
  15. L

    Calculating Mass in a Gas Stoichiometry Problem

    Hi all, While studying for my exam (and doing review questions) I came across a problem that I couldn't solve: 5. Zirconium metal and chlorine gas react to form zirconium (IV) chloride Zr + 2Cl2 = ZrCl4 a) What volume of chlorine gas must be used at 350 degrees Celsius and 50 kPa to produce...
  16. Chestermiller

    Reversible Vs Irreversible Gas Compression/Expansion Work - Comments

    Chestermiller submitted a new PF Insights post Reversible Vs Irreversible Gas Compression/Expansion Work Continue reading the Original PF Insights Post.
  17. K

    Energy source for long-term constant gas pressure?

    Gas pressure in a closed chamber at constant temperature will last forever, unless leaking or chemical reactions occur. Examples are methane in underground gas reservoirs that are hundreds of thousands of years old. Gases stored in bottles. Pressure comes from the gas atoms (with velocity)...
  18. P

    Temperature of a gas in a container

    A rectangular (simplified) container with rigid surfaces, has a certain mass of ideal gas within it, and it accelerates in free space, undergoing rectilinear motion. There are no dissipative forces. Now, since the container moves, its kinetic energy increases, and since the temperature of the...
  19. R

    Calculation for knowing duration of gas cylinder

    I know the total volume of a gas cylinder, the pressure in it, and the outlet pressure that needs to be maintained. The flow rate is also known. How should I calculate the total duration the cylinder will last? Also, what should vary if the cylinder is a liquidified gas cylinder?
  20. M

    Gas consumption vs oven temperature setting point

    Haw can I calculate/estimate the potential gas consumption in an industrial oven after the reduction of the temperature setting point?
  21. J

    Solving Ideal Gas Problem: Find # of Balloons Filled

    Homework Statement A gas cylinder contains 4x10^4 cm cubed of hydrogen at a pressure of 2.5x10^7 Pa and a temperature of 290 K. The cylinder is used to foll balloons. Each balloon contains 7.24x10^3 cm cubed of hydrogen at a pressure of 1.85x10^5 and a temp of 290K when full. Find the number...
  22. M

    Find the molar specific heat for each gas.

    Homework Statement A mixture of two ideal gases, the first one atomic and the second two atomic are put in normal conditions in a calorimeter with volume 1 liter hermetically closed. After it is given 10J thermal energy the mixture temperature is grown 14.2 K. Find the molar specific heat for...
  23. M

    Find the growth of temperature of the gas

    Homework Statement A mass of 3 mole gas is heated in a constant pressure of 1.5 atm, expanding from 40 litre to 60 litre. Find the temperature growth. Homework Equations V1/V2=T1/T2. The Attempt at a Solution I thought to write V1/V2=T1/T2. But I don't know T1. The answer is 121 K in my book.
  24. EinsteinKreuz

    Sagittarius A*: the riddle of gas cloud G2

    So perhaps I'm not the only one here on PF who's heard about this .That said, besides the gas cloud G2 concealing a low-mass star, I cannot help but wonder what azimuthal angle G2 made its closest approach to the supermassive black hole Sagittarius A*. The reason this is relevant is because...
  25. P

    I need some kind of propellant gas for an experiment

    For the past year or so, I've been experimenting with Isobutane. I used to get it in relatively cheap canisters of r600a from amazon.com and AliExpress, and that worked fine. Now, however, AliExpress has NO purchase options for r600a, and amazon.com will not ship it to the US, even though they...
  26. S

    Average kinetic energy of particles of an ideal gas

    Homework Statement So first the task: Determine the average value of the kinetic energy of the particles of an ideal gas at 0.0 C and at 100 C (b) What is the kinetic energy per mole of an Ideal gas at these temperatures. I took the above right out of the pdf we got from our professor. I know...
  27. Robsta

    Interferometer to measure refractive index of a gas

    Homework Statement I've uploaded a diagram showing a two beam interferometer that can be used to monitor changes of refractive index in a gas cell. it is illuminated with monochromatic light of wavelength λ. The light is linearly horizontally polarised. The two polarizing beam splitters (PBS)...
  28. C

    Substitute a gas motor with electric motor

    I'm sure that this has been posted before but... I want to substitute a gas motor in my 12kw Generac home backup generator with an electric motor 48-volt 4hp@4000 rpm series.. I would run this electric motor from the grid and power my home from this newly design generator.
  29. B

    Calculating Gas Pressure: Solving for Pressure in a Variable Volume

    Homework Statement Gas occupies 2m^3 at a pressure of 100kPa. What is the pressure when the volume is 1.5m^3 and the temprature is unchanged? Homework Equations p=nRT/V The Attempt at a Solution As a logic conclusion i took 1.5/2x100 and got 75 but 175 is not the answer.. The answer is...
  30. M

    Calculating temp change releasing a compressed gas

    Hello, I understand when you release a compressed gas generally it comes out cooler than atmosphere. But here are my questions: When you fill the container, the gas warms up as the pressure builds. Generally it takes a long time to compress and I believe the temperature of the gas when it's...
  31. S

    Electron-hole gas density in different materials

    If we connect a two metals with different Fermi levels electrons will start to flow from metal with higher Fermi level to a lower one. Untill metal with lower Fermi level will get negatively charged and the process will stop. But what if we connect a two materials with different Fermi levels...
  32. T

    Gas Dynamic to Acoustic wave equation

    Homework Statement Derive from the formulas ##\frac{D^\pm}{Dt}(u \pm F) = 0## where ##\frac{D^\pm}{Dt} = \frac{\partial}{dt} + ( u \pm c) \frac{\partial}{\partial x}## the one-dimensional wave equation in the acoustical limit. \begin{cases} u << c\\ c \approx c0 = const\\ F =...
  33. goonking

    Ideal gas law in terms of density

    Homework Statement Homework Equations PV=nRT The Attempt at a Solution not sure if this is the right approach plugging into -ρg gives us -PMg/RT = dP/dy now we have to integrate both sides to find P?
  34. JosephLa

    How is centrifugal force created in a cloud of gas in space?

    First, may I apologize in advance if this question is in the wrong section of the forums. Given a cloud of mixed gasses and rocky material, how is spin created when a star is born? I will also give the cloud of gas a random order of movement prior to star formation. Can the physics for the...
  35. R

    A heating element in a container with low pressure gas?

    This is just a qualitative question but feel free to show an equation if possible. Basically if you have a container with a heating element, let's say 500 W with a temperature of 2500 Kelvins and inside this box is a low pressure ideal gas, something like 1/100 of an atmosphere. Also imagine...
  36. R

    Pressure and force in a cylinder

    A cylinder containing oxygen gas O2 has a piston that can move unfazed by friction. The piston has a diameter of d = 16cm. The oxygen gas has a temp of 40,0 degrees Celsius and a pressure of 145kPa. The pressure outside the cylinder is 101kPa. The piston is held in a stationary position s =...
  37. S

    Why Is Time Represented as 2d/v in Kinetic Gas Theory Calculations?

    To obtain force from momentum we use the formula change in momentum/time. The time in the equation refers to the amount of time the force is exerted on the gas molecules. So when considering the kinetic theory of gases we are taught that F ∝ change in momentum/ time so F ∝ 2mv/(2d/v) and hence...
  38. R

    Role of TiO2 in Gas sensor Device

    Good day, TiO2 have many possible application in material science, one of this is in Memory device, base on some literature TiO2 had a good chemical stability at high temp, so this is one reason why TiO2 is best candidate for this application, but beside of that, what other properties of TiO2...
  39. D

    Compressing ideal gas, show no heat exchange

    Homework Statement An ideal monatomic gas is contained in a cubic container of size ##L^3##. When ##L## is halved by reversibly applying pressure, the root mean square ##x##-component of the velocity is doubled. Show that no heat enters of leaves the system.Homework Equations ##dU = dQ -pdV##...
  40. CheesyPeeps

    Solve Combined Gas Law: National 5 Physics Exam Help

    I am studying National 5 physics, and my exam is tomorrow. I need some last-minute help. I'm struggling a little bit with the combined gas law, P1V1/T1 = P2V2/T2, and I'm not sure why. It would help me a lot if you could show step-by-step how the formula is used. Thanks for your time, it's very...
  41. Mantikore

    Rolling resistance, tire tolerance, gas mileage

    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...
  42. R

    Trying to relate nuclear physics to solid state (fermi gas)

    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...
  43. Artlav

    Calculating optical properties of an arbitrary gas?

    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...
  44. voltech444

    Gas Turbine Afterburner Water Injection

    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...
  45. Spinnor

    Thermodynamics of gas in very strong gravitational field.

    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...
  46. evan manalu

    Generating Electricity from Gas: Is It Possible?

    Can us generate electricity just from gas? I meant not by steam generator but by ionize gas,for example from original air gas?
  47. R

    How does gas behave/flow in different sized tubing/piping?

    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...
  48. throneoo

    Degrees of freedom of diatomic gas

    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...
  49. T

    What is the temperature increase of the gas?

    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...
  50. R

    What is the Ideal Gas Force on a Container at Temperature T?

    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...
Back
Top