I'm a first year electrical engineering student and in my General Chemistry class, every other week, we're required to write a paragraph about how each weeks material relates to your future career. As I am in electrical engineering, I don't see much relation to any topic. This week is...
I have a question regarding an occurrence with Nitrogen gas and two separate containers. I'm trying to explain why when I fill my steel pressure vessels to ~180psi on an avalauncher from a larger 2000psi steel tank, the pressure slowly drops to ~175psi after the fill. I believe this to be...
I know that this topic has already been covered (kind of) in a separate forum post, but it became rather confused and there were many differing and contradicting opinions/supposed facts, so I just want to clarify a few things.
Firstly, are gas turbines more or less efficient (useful mechanical...
Homework Statement
An ideal gas with adiabatic index γ is taken around a complete thermodynamic cycle consisting of three steps. Starting at point A, the pressure is increased at constant volume V1 from P1 to P2 at point B. From point B to point C, the gas is allowed to expand adiabatically...
Hello,
Given: A large pressurized container with a small hole in a side. The sides of the container are VERY thin such that the thickness of the sides can be ignored. The pressure difference between the container and the environment is not large enough to result in choked flow. The outflow...
I am building a Rapid Pulse Carbonation prototype Reactor unit, I am capturing the Steam form the process and passing it though a Plate and Tube condenser to produce water, also I will capture the CO2 gas from the heating system. How would I reduce the exhaust gas heat before I pass the exhaust...
East Coast faces gas shortages, price hikes after pipeline leak (CNN.com)
That pipeline passes about 20-30 miles from here.
This morning I stopped at my usual gas station, one of the cheapest around here. There were more people there than usual, and a couple of the pumps had gone empty. While...
Assume: Hydrostatic Situation, ideal gas
Use empirical formula T = T0 - Bz
I have rechecked my work several times and can't seem to find a mistake. The answer is supposed to be:
p2 = p1((T0 - Bz)/T0)(g/Bz)
dp/dz = -ρg Now substitute ideal gas equation for ρ
dp = -(p/RT)g dz
∫(1/p) dp...
Hi, are there any experimentalists here? I have gas in a cylinder. I have just been taking samples of gas from a tube connected to the outlet, but air is getting in the syringe.
So I went over to chemistry and got a round bottom flask with 3 inlets / outlets and a septum, so its like this:
I...
I understand that pure water that's being aerated will only take up just so much dissolved oxygen (DO) and that that depends on the temperature of the water. I see ranges of 14 ppm at close to freezing and around 6 ppm at 50 C as normal maximums.
I understand, too, that you can temporarily...
We discovered a leak in a SF6 gas HV circuit breaker. Since we don't know when the leak occurred due to temperature changes I assume there is only air left in the tank.
Here is my question. Suppose I have a tank with a fixed volume filled with air at the same pressure as the atmospheric...
Homework Statement
An ideal monatomic gas has initial pressure Po and occupies initial volume Vo. The gas undergoes an adiabatic expansion in which the volume is doubled. Calculate in terms of Po and Vo
a) the final pressure of the gas
b) the change in its enthalpy during the...
Homework Statement
The pressure in a bulb dropped from 2000 to 1500 mm of mercury in 50 minutes when the contained oxygen leaked through a small hole. The bulb was then evacuated. A mixture of oxygen and another gas of molecular weight 72 in the molar ratio of 1 : 1 at a total pressure of 6000...
Homework Statement
A current ## I=0.2 A ## flows in a resistor ##R = 50 Ω## immersed in a rigid adiabatic vessel that contains ##n=3## moles of Helium. The initial temperature of the system is ##T_0 = 27 °C##. The resistor has a mass ## m = 10 g## and specific heat ## c = 0.2 (cal/K)/g ##...
Homework Statement
An expandable cylinder has its top connected to a spring of constant 2000 N/m. The cylinder is filled with 5L of gas with the spring relaxed at a pressure of 1 atmosphere and a temperature of 20C. If the lid has a cross-sectional area of 0.01m2 and negligible mass, how high...
I've gone through many posts but haven't really come across something very clear. And on top of it my knowledge of fluid dynamics only extends to compressible fluids.
I have a Nitrogen Cylinder Tank, with an exit pressure of 214.7 psia which is blocked by a solenoid valve at a location very...
http://www.fluidmechanics.co.uk/
I have found this by searching net. The inventor claimed that by using a new kind of piston fitted with fins, he achieved almost isothermal compression and greatly reduced the power consumption process. I want to know how much theoretically sound it is.
May I start by saying hello to all and that I have visited the site before, but have yet to create an account until now. With that said, I am having difficulty calculating proper numbers for a project I am designing. Mind you, it has been about seven years since I was in any physics or...
I have been reading about and contemplating the early stages of star formation lately. An interstellar cloud collapses under it's own gravity to form a star. There is much data about what could trigger it, and what happens when the gas heats up or starts fusing.
However, i couldn't find...
Hi Guys
I´m studying the absorption and emission phenomena of a gas and, according to Kirchhoff "extended" law, for a body at thermodynamic equilibrium, the following statement is true.
ελ(T,θ,φ) = Aλ(T, θ,φ).
So, if i understood correctly the meaning of this equation, The amount of absorbed...
In the gas industry engineers often have to purge gas pipes. For example, if repair work must be done on a gas line the fuel gas in the system must be removed before work can be done safely.
The Institute of Gas Engineers and Managers (IGEM) publication IGE/UP/1 stresses the need to achieve a...
Today, one of my professor was teaching about Circuit Breaker and he explained about SF6 circuit breaker. He told us that SF6 is electronegative gas. But i really didn't understand what is electronegative gas. Please can someone explain in detail. Thanks in advance.!
So I was reading about Tesla's plan for battery swapping. I didn't think that was such a great idea, since you would be leaving behind something that was a good fraction of the cost of the car. Might there be a better way?:
So, it's the future: You've been driving around town, and used up...
Homework Statement
Homework Equations
The Attempt at a Solution
I do not know exactly how to start this problem.
I would really appreciate it if you could give me some hints.
I know that e^ - t/tau=T(t)-Twall/Ti-Twall
where tau=m*cp/hA
where h=convective heat tr.coeff
and T(t) is desired temp...
Homework Statement
Here http://imgur.com/a/4LRM6
2. Homework Equations
The equation is given int he questionThe Attempt at a Solution
gas will stop flowing when the pressure inside the gas is equal to that of the surroundings. I calculated the final mass of gas inside the cube. Then i...
Homework Statement
Why doesn't the temperature of a moving jar of gas increase?
Homework Equations
Average KE is proportional to temperature
The Attempt at a Solution
This is just an extension of a problem my friend sent me, and I'm stuck on why even though average velocity is increasing...
Homework Statement
Using equipartition law, find specific heat of gas containing triatomic linear molecules. Will the result be different if the molecule was non- linear? In what way?
Homework Equations
According to equipartion theorem, each degree of freedom gets (1/2)kT kinetic energy and...
1. The problem statement, all variables and given/known
Mg metal reacts with HCl to produce hydrogen gas. What is the minimum volume of HCl solution (27% by weight) required to produce 12.1 g of H2? Density of HCl solution is 1.14 g/cm3Homework Equations
[/B]
This question...
Hello,
I am currently working on a storage project which allows me to decouple the compressor from the expander of a gas turbine. (see image link below)
The reason I use a gas turbine is to reheat the air which was cooled after being compressed. As you can imagine there is a efficiency loss...
Hello
i have done tests on Exhaust gas re circulation on my engine test bench and these are the results, i don't know what's wrong? but at 8% loading conditions i am getting some weird results
the trendlines in the graph shows an increase in NOx with EGR
is there any explanation for this ? thanks
Hi
I am not sure if this is the correct forum to post this on, but I guess it can be moved if it is not.
I just want to know what methods exists to detect gases in a room. Smoke alarms use ionization or electromagnetic light.
What other technologies exist on the market? What technologies are...
Hello. I am having some trouble with a work related problem. I have a GLP tank of 5000 litres capacity, and we actually have a pressure gauge on it measuring that the gas pressure on top of the liquid is above tolerance.
Based only on that data, we need to measure the volume that is being taken...
Homework Statement
Homework Equations
PV = nRT
The Attempt at a Solution
##PV^2 = constant##
Differentiating both the sides we get , ##V^2dP + 2PVdV = 0 ##
Now , using this along with ##PdV+VdP=nRdT## , we get ## PdV = - nRdT ## .
Since ##dV## is positive , ##dT## is negative which...
Edit: Eh, sort of changed the question part way though, so if a mod could change the title to "Question regarding gas flow from high to low pressure".
Moderator edit: Done
I'm about 99% sure I already answered this question for myself but just wanted to make sure my logic was correct, so if...
Hi there,
I took the course of quantum mechanics long time ago. From there I learn how to describe an atom with wave function. For example, Hydrogen has the wave function in (spherical coordinates) space. In the book they consider a reduced mass for the nucleus and the only external electron...
Hello, PF!
I'm currently brushing up my fluid mechanics and came across some questions while studying the compressible flow of an ideal gas using Bernoulli's equation. First, consider incompressible flow in the following system
Neglecting any changes in elevation, the Bernoulli equation for...
Edited: To summarize the below attached jpg file is the formula for work done by a van der waals gas in a isothermal reversible expansion.
Is there a way to find the work done by a van der waal gas in a isothermal irreversible expansion? i.e the real gas expands against a constant pressure (in...
Consider an ideal gas following a thermodynamics cycle, represented on a ##P-V## plane. I read that if the cycle is "travelled" clockwise then ##W_{gas, cycle}>0## so the gas does positive work, while if the cycle is "travelled" counterclockwise then ##W_{gas, cycle}<0## but it seems to me that...
Here I want to know how to find the heat interactions of non-ideal gases in the following processes.
1. Isobaric process
2. Isochoric process
I know that internal energy U depends on temperature and volume. And the enthalpy depends on temperature and pressure.
How calculation of heat...
I was uncertain wether to put this in the general physics forum, but I decided against it.
How do length adjustable gas springs(like for example in office chairs)work ?
I know how gas springs work and i even have an idea how length adjustable ones could work.
Since you hear a "gas flowing...
Homework Statement
Calculate the kinetic energy of CO, CO2, and SO3 at 276 K .
Homework Equations
KE = (3/2) RT
KE= (1/2)(mass)(velocity)^2
The Attempt at a Solution
[/B]
For CO:
First attempt: KE=(3/2)(RT)=(3/2)(8.314 J/mol-K)(276K) = 3441.996 -- So that's wrong
Second attempt:
Relative...
Homework Statement
For a gas of N fermions of mass m confined in a volume V at a temperature ##T<E_F/kB##, consider the quantity ##<n_p>/V## as you would a classical distribution f(p,q) in the system phase space. Show that the impulse transfer of the elastic collisions of the particles with the...
Homework Statement
For some gas specific heats for constant pressure and constant volume are calculated. Universal gas constant is R. Find the formula the helps identify the gas. Include only constants and given information.
Homework Equations
3. The Attempt at a Solution [/B]
Molar specific...
Homework Statement
For a gas of N fermions with mass M in 2D in a region of area A in thermal equilibrium at temperature T, we are asked to find ##U/N## in fuction of ##T## and ##a=A/N##.
The attempt at a solution
I used ##U=\sum(<n_i>\epsilon_i) = \sum(\exp(\beta(\mu-\epsilon_i))\epsilon_i...
Apologize if you feel this question to be so simple and naive.
Suppose a chamber is divided by a insulator into two equal volume (V) chambers, . One chamber contains n moles of hot oxygen at temperature T1, the other chamber contains n moles of cold oxygen at temperature T2. If you move the...
Hi.
In some statistical approaches (e.g. canonical ensemble), the particles of an ideal gas are non-interacting. Still, it's possible to derive the ideal gas law and other thermodynamic relations.
Wikipedia gives an equation for the speed of sound in an ideal gas. How can there be waves in a...
Homework Statement
The figure at the bottom shows a cylindrical tank of diameter D with a moveable 3.00-kg circular disk sitting on top. The disk seals in the gas inside but is able to move without friction. The gas inside is at temperature T. The height of the disk is initially at h = 4.00 m...
what is the best quality to know if a gas for example became solid ...soldification
Speacking about small quantity of gas that we can't see with our eyes ...
what electrical quantity that i need to read to know that this very light gas become a solid metal and could that quantity give me...
Homework Statement
3: When the temperature is increased slightly above T = 0, it is self-consistent to assume to that the chemical potential stays \mu(T) = 0, as long as there is a macroscopic number N0 oscillators in the ground state (You should not prove this!). The N atoms in the system are...
My dad and I were going to fill up a tractor tire that was very flat. We had two air tanks, a small (~5 gallons) and a large air tank (~10 gallons) which were both filled to the same pressure (~100 PSI).
We wanted to pressurize the tractor tire as much as possible with the two tanks, and so my...