Gas Definition and 1000 Threads

Hello, I'm having a problem calculating the final pressure before condenser. I'm calculating the pressure that builds up in a system that at the beginning has atmospheric pressure @ T=20C and is introduced with 1 mole/second of CO2(44.01g/mol) @ T=60C and 0.318 mole/second of CH2Cl2(84,93 g/mol)...

Hi. I just read an article where following cooling method is described. Apparently it's very common, but I don't know what it's called: A gas under pressure is released into a vacuum through a small hole. The average particle speed in this beam of gas is the same as before, but the...

Homework Statement Why does a gas behave as ideal if the Isotherm and Isenthalp are parallel. Homework Equations h=u+pv T1=T2, P1V1=P2V2 The Attempt at a Solution [/B] h1=u1+p1v1, h2=u2+p2v2 h2=h1 so u1+p1v1=u2+p2v2 and p1v1=p2v2 Does that mean internal energy for an ideal gas is zero? I...

The international Journal of Greenhouse Gas Control. It has an Impact Factor of around 4, but what's the perception? Is it respected? Is it considered a good journal? There isn't a qualitative judgment online. My boss seems to look down on it, but it has a good impact factor.

Homework Statement A vertical cylinder of radius r contains an ideal gas and is fitted with a piston of mass m that is free to move. The piston and the walls of the cylinder are frictionless, and the entire cylinder is placed in a constant-temperature bath. The outside air pressure is p0. In...

Why is it that dark matter does not inhabit gas clouds, I would have thought that thees gas clouds will some day become a galaxy, so why no Dark Matter?

Hey Mech Eng Forum, I'm currently examining the performance on gas turbine and wondering: How is the performance of gas turbines (Primarily thermal efficiency and net-work output) influenced by the pressure ratio and temperature constraints? Additionally, what is the benefit of 2 stage...

i'm trying to understand the solution to this problem: http://physweb.bgu.ac.il/COURSES/StatMechCohen/ExercisesPool/EXERCISES/ex_2065_sol_Y13.pdf (link to the problem and the solution of it) All my questions come from the partition function: 1) From where the term (2*pi)^d comes from?, I...

Hi all, If I have a hot object in space (not a star but say an oven or just a hot gas as would be on Earth < 10,000 degrees Kelvin) glowing at a temperature T and I want to know long it takes to come to equilibrium with the vacuum of space around it, how can I calculate such a time? I could...

MENTOR NOTE: NO TEMPLATE BECAUSE SUMITTED TO WRONG FORUM. 3.1) A quantity of 0.10 mol of an ideal gas A initially at 22.2 degrees C is expanded from 0.200 dm3 to 2.42 dm3 . Calculate the values of work (w), heat (q), internal energy change (delta U), entropy change of the system (deltaSsys)...

Homework Statement Only Number 1, not number 2 Homework Equations Dew Point Temperature T = Saturated Temperated at Vapor Pressure Partial Pressure = (mole fraction) x (Mixture Pressure) The Attempt at a Solution The dew point temperature is only dependent on the pressure of the water...

Homework Statement Only Number 1, not number 2 Homework Equations Dew Point Temperature T = Saturated Temperated at Vapor Pressure Partial Pressure = (mole fraction) x (Mixture Pressure) The Attempt at a Solution The dew point temperature is only dependent on the pressure of the water...

How much helium would a gas cooled reactor require for startup and loss replacement? Would helium's scarcity pose a major obstacle to widespread or long term adoption of it as a coolant for nuclear reactors?

So, this is just a simple question that crossed my mind. When say, a blowtorch or propane tank is ignited, how does the entire canister not go up in flames? How does the flame only stay on the outside and not burn through to the inside where the gas supply is? Will whatever principle this works...

Homework Statement In the open cylindrical chamber is the piston of the total mass m. The initial air pressure inside the container is pa, the initial temperature T0. The initial height of the piston above the bottom h0. Now we start the gas supply heat to the moment when the piston reaches the...

out of the gasses hydrogen,nitrogen,chlorine, and helium which shows behviour closest to an ideal gas.? ive been told the answer is helium because there is no attractive forces between helium atoms. would there not be van der waal forces though.? also would hydrogen just have as little...

I'm confused on why the dry air gas constant varies: Dry Air Gas Constant of 286.9 from The Engineering Toolbox Dry Air Gas Constant of 287.22 from https://www.physicsforums.com/ttp://www.peacesoftware.de/einigewerte/luft_e.html Dry Air Gas Constant of 287.05 from Brisbane Hot Air Ballooning...

I have a question about thermal expansion of liquid into a gas void. Imagine a closed upright cylinder filled mostly with water – say 99%, and the remaining 1% is gas. Now imagine that you heat the cylinder and its contents. The water will expand by ΔV owing to thermal expansion. The gas...

Homework Statement Assume 1.500 mol of a monatomic ideal gas is compressed from 3.00 L to 1.00 L. a. If the initial and final temperature is 10.0 °C, what are the initial and final pressures (in atm)? b. How much work input (in kJ) is required if a reversible isothermal path at 10.0 °C is...

Homework Statement Why is the formula ##p = \frac{1}{3}\rho<c^2>## used to calculate the mean square speed at 273K? Why 273K?

Hi, In an enclosed system - of say Methane & water - in which the water column is sufficiently large to have significant pressure and some modest temperature difference due to gravity and geothermal effects, how would one calculate / predict the changing methane concentration (or partial...

If I have a 1/2" source hose with 60PSI and a Flow sensor then split to four 3/8" hoses with a flow rate limited to 30SCFH. Should I expect to have a 120SCFH flow rate across my flow sensor? The gas will be 90% Argon/10%CO2, but we could assume an Ideal Gas for this... Right? I understand...

What I want to discuss here is what happens to the thermal velocity when an ionised gas molecule has been put into an electric field. Due to the charge (e) and potential difference (V), how much velocity has been gained by the ion can be calculated easily.eV = ½mv2 Where e is the charge of the...

Homework Statement In temperature 273 kelvin and pressure 1.013*10^5 Pa, the density of nitrogen is 1,25 kg/m3. Find the density of this gas in temperature 330 kelvin and pressure 1.40*10^5 Pa. T1=273 K; p1=1.013*10^5Pa; d1=1.25 kg/m3 T2=330 K; p2 =1.4*10^5 Pa. d2=? Homework Equations...

Hello ! I am currently investigating a technique that would allow several spark gaps to breakdown synchronously in an enclosed but not hermetical cavity, flushed with N2 at 1atm and ~25°C My idea was to use "indirect" photoionization (basically a synthetic fused quartz UV flash discharge inside...

Homework Statement A vertical heat-insulated cylinder is divided into two parts by a movable piston of mass m. Initially, the piston is held at rest. The top part is evacuated and the bottom part is filled with 1 mol of monatomic gas at temperature 300 K. After the piston is released and the...

Homework Statement X and Y are two gas bottles that are connected by a tube that has negligible volume compared with the volume of each bottle. There is a valve in the tube that is initially closed. X has a volume of 2V and contains hydrogen at a pressure of p, Y has a volume V and contains...

I have been pondering. Why is it that we use the rms speed in the equation Ek = 1/2 m vrms2, as opposed to just the mean speed2

"How it can be explained mathematically by dP/dV = -gammaP/V

Hey I was hoping someone could be me a succinct method of knowing what form of the Ideal gas law I need to use and in particular the different R's associated with each form. Form my Thermodynamics class we use PV = nRT Pv = RT PV = mRT Little v being the specific volume (which changes the R...

Hi , a simple question arose in my head , why is that every time I have seen a hose attached to a gas tank being set on fire the fire always burns out of the end of he hose but the fire never travels backwards inside the hose back to the tank to explode it. the same I suppose happens to a...

Homework Statement A cylinder containing an ideal gas is in vertical position and has a piston of mass ##M## that is able to move up or down without friction (Fig. 13.2). If the temperature is increases, ...Fig (13.2) (a) both ##p## and ##V## of the gas will change. (b) only ##p## will...

Homework Statement Please consider a mixture of oxygen (1 mole), nitrogen (4 mole), and carbon dioxide (3 mole). The mixture was heated in a well - insulated vessel with 753 kJ. Determine the final temperature if the mixture is composed of real gases behaving ideally as described by Eq. 3.48...

Homework Statement an Ideal gas at T = 70 C and 1 bar undergoes following reversible processes: a: Adiabatically compressed to 150 C b: then, cooled from 150 to 70 C at constant pressure c: finally, expanded isothermally to the original state (T=70 C and P = 1 bar) Homework Equations...

Hello! I have this GRE question: In process 1, a monoatomic ideal gas is heated from temperature T to temperature 2T reversibly and at constant temperature. In process 2, a monoatomic ideal gas freely expands from V to 2V. Which is the correct relationship between the change in entropy ##\Delta...

Homework Statement "One way to heat a gas is to compress it. A gas at 1.00 atm at 25.0°C is compressed to one tenth of its original volume, and it reaches 40.0 atm pressure. What is its new temperature?" So, I have: P1 = 1 V1 = 1 T1 = 25 P2 = 40 V2 = 0.1 And I'm looking for T2 The question was...

Homework Statement 1 mole of ideal gas with internal energy U= 3/2 RT , expands from initial volume Vi = 1/10 Vo following the equation p=(− po / Vo ) V +po . Find (a) the highest temperature reached by the gas during the expansion and (b) the maximum amount of heat taken in by the gas...

Question (see attached diagram): PV diagram with 7.5 moles of ideal diatomic gas through cycle a, b and c. What is the highest temperature reached by the gas during the cycle? (multiple choice answers 180, 325, 208 and 100 C, i know answer is 208 C but I'm not getting it!) It is a PV diagram...

Hi All, Is there anybody who can help me with this question? Example: What is the enthalpy of CO2 in 200psig and 80deg.F? I have a software, but I'd like to see the calculation steps. Thanks Ding

Hi, I'm working on my thesis and I need to calibrate some gas sensors that I'm building. I need controlled conditions(temp, RH and a known gas concentration) in order to calibrate the sensors. I'd love to know some idea to make a sealed box in which I trace and vary those parameter. I've...

The graphs of intensity versus wavelength of blackbody radiation and of number of molecules versus speed in a gas look very similar to me. Is this just a coincidence? They seem like quite different phenomena.

Is this answer is proper? Propane is a natural component of natural gas and is removed during the refining process. Most gas appliances can be converted from one fuel to the other by changing the burners on a stove or changing or adjusting a gas regulator located inside the appliance according...

Homework Statement A frictionless piston of mass m is a precise fit in the vertical cylindrical neck of a large container of volume V. The container is filled with an ideal gas and there is a vacuum above the piston. The cross-sectional area of the neck is A. Assuming that the pressure and...

Suppose there is an enclosed container having air inside at say 4 barA pressure. Now, a hole has been made at one of the walls of the container and by another hole, air is continuously injecting inside so that the pressure wouldn't fall. Now, with what speed the air from the container will come...

Hi. If an ideal gas of ##N## particles is allowed to expand isothermically to double its initial volume, the entropy increase is $$\Delta S=N\cdot k_B \cdot \log\left(\frac{V_f}{V_i}\right)=N\cdot k_B \cdot \log\left(\frac{2V}{V}\right)=N\cdot k_B \cdot \log\left(2\right)\enspace .$$ This can...

I am trying to model fluid flow and losses through a component (e.g., pipe) using REAL GAS properties since 1) I have access to RefProp from NIST, and 2) I am dealing with refrigerants, which are far from ideal. I have seen nowhere an analysis of fluid flow losses (e.g., drag, friction...

Homework Statement A valve is required to regulate the flow of natural gas. Details of the gas are given in table below. It can be assumed that the pipe size and the valve size are the same [i.e. piping geometry does not have to be allowed for]. The chosen valve type is the V250 rotary ball...

I found a thyratron tube at a yard sale recently and I want to build a circuit to heat the filament and illuminate the mercury vapor for purposes of building a novelty lamp. The filament is just 2.5VDC at 7 amps and I have a transformer for that. To light the vapor I will apply DC rectified...

Homework Statement If air has a density of ρ0 on the surface, calculate its density as a function of the height y for two scenarios: (a) the temperature is constant at T0; (b) the temperature decreases linearly T(y) = T0 − ay. Express your results using the given variables together the...

Several undergraduate and graduate students and I are building a small engine powered by Compressed Natural Gas (CNG). It is a small and straightforward affair, similar to what is found in small equipment such as chainsaws and lawn mowers. I wanted to experiment with Liquefied Natural Gas (LNG)...