Gas Definition and 1000 Threads

As Avagadro states: "One mole of an ideal gas at STP occupies 22.4 liters." This doesn't seems counterintuitive since we know that we need a volume to compress the gas. But how can we explain quantum ideal gases. Especially in my case, Bose gases. Since well-known example is Helium 4, we might...

I have really problem with equation of the root – mean – square (rms) speed of the gas molecules when we use the universal gas constant (R) mentioned in all references. Accordance to all reference books, we have below equation for the total translational kinetic energy: Vrms = (3RT/ M)^0.5...

From reading about the permeation of gasses through polymer seals, I am led to believe that given two identical sealed chambers, one containing a vacuum and the other pressurized perfectly dry nitrogen, water vapor would permeate through the seals and into the chambers at the same rate. This...

Hi! I'm new to the forums and currently reading about Chemical Thermodynamics. So here's what I know: ΔE = q - w So for constant volume reactions, no work is done hence: ΔE = q But for constant pressure reactions, heat be may released (for exothermic reactions) and work is done hence: ΔE =...

Hi .I'm a beginner at thermodynamics,very limited in my understanding of math.I have a handbook on CO2 properties.According to it the properties for CO2 at 47.3 bar are T=12C,H= -3792,S= -42.6,and for 34.85 bar, T= 0 C,H= -3339.8,S=-39.33.If the gas expands from 47.3 to 34.85 bar,the gas will...

Homework Statement A sample consisting of one mole of a diatomic perfect gas is heated from 25 °C to 200 °C at constant volume. Calculate q, w, ΔU and ΔH for the process, given that Cv = 23.02 J K-1 mol-1 . Homework Equations Im studying for mid terms and i have no lecture notes on diatomic...

Can anyone please answer this question? I have read that increased temperature increases entropy and increased pressure decreases entropy ,for a gas.And vice versa.decreased temperature decreases entropy and decreased pressure increases entropy.Can anyone please tell me for a gas under pressure...

These noble gases do not react with hydrogen or oxygen.but Mendeleev basically classified by observing their reactions with hydrogen or oxygen. Or were these gases fit according to their atomic mass? If so,how did he find it's atomic mass without knowing it's reactivity?

Homework Statement A gas in equilibrium has distribution function: f(p,r) = C0*(1+y*x)(2*pi*m*k*T)-3/2*exp(-p2/(2*m*k*T)) where x is the distance along an axis with fixed origin, and y is a constant. What's the nature of the force acting on this gas? Homework Equations Maxwell bolztmann...

Let's assume that weights are placed on a massless piston and below the piston is a gas. If we remove all the weights at once, the work done by the gas should be the difference between the forces exerted by the gas and the atmosphere multiplied by the change in volume. However, we know that the...

This is a thermodynamics question.I am a beginner and know only algebra.Here's a description.A cylinder full of CO2 gas at 670 psi is compressed by a piston.At the far end of the cylinder is a pipe,through which the CO2 gas flows to push a piston into another cylinder.At one third of the stroke...

Hello all, This is my first post, but I'm no stranger to skimming the boards. Always can find helpful stuff, but I'm stumped on this one. The situation is we have a Kohler 17 hp electric start gas engine horizontal shaft that max's out at 3600rpm. We are attaching a self-priming water transfer...

Homework Statement 1 liter of ideal diatomic gas (allow for rotation but not vibration) at a pressure of 1 atmosphere and a temperature of 300 K is compressed adiabatically to a pressure of 7 atm. What is the volume of the gas after compression? Homework Equations PV=NKT PV=nRT ##U_T##=f/2*NKT...

Homework Statement [/B] Two balloons with Helium gas are filled, first with 10 liters of He and second with 20 liters. Molecules of which balloon will be moving faster as compared to the other? Homework EquationsThe Attempt at a Solution Speed of molecules is directly proportional to...

Homework Statement I[/B] have some difficulties proving that the ideal gas temperature is directly proportional to absolute temperature defined by the second law of thermodynamics. Homework Equations The ideal gas temp. is defined by the ideal gas equation: pV=NkTi(T), where k is Boltzmann's...

Homework Statement in this notes , i was told that the PV=mRT , why ? shouldn't PV= NRT , N=number of moles ? it should be PV = m/M (RT) , right ? Homework EquationsThe Attempt at a Solution

Homework Statement As attached. Homework EquationsThe Attempt at a Solution I chose A but the correct answer is E.(Actually I thought both of them were correct) From the graph provided,it is clear that the turning point corresponds to the largest proportion of molecules,so is the corresponding...

Dear PF Forum, As per wiki: https://en.wikipedia.org/wiki/Standard_enthalpy_change_of_formation_(data_table) Standard enthalpy of water: Gas: -241.818 kJ/mol Liquid: -285.8 kj/mol What does it means? That to produce H2O per mol at 1000C, it releases 241.818 kJ. That to produce H2O per mol in...

I just read Paul Davies book The Eerie Silence. In The Eerie Silence, Paul Davies asserts that the radio astronomers looking for radio signals from extraterrestrial civilizations search for radio signals at the frequency 1420 MHz because that is the emission frequency for cold hydrogen gas...

Homework Statement Hi, I have the following task: Translated into English, that means: " For Cpm and Cvm of gases the following relationship is true: (1) a) Show with the relationship (1), that for an ideal gas Cpm - Cvm = R is valid b) Deduce from equation (1) and the tripple product rule...

THE PROBLEM: A steam engine's boiler completely converts 2638 g of water at 83.7 °C to steam at 195.4 °C. The steam, at a constant pressure of 3.28 Pa, expands by pushing a piston of radius 9.4 cm a distance of 8.3 cm. What is the change in internal energy of the water-steam system? MY WORK...

Homework Statement Methane at ## P_1 ## and ## T_1 ## is compressed to a pressure of ## P_2 ## adiabatically at steady-state. Calculate the work done on the compressor and the temperature ## T_2 ## of the discharge gas. Use ideal gas model. Given: ## T_1, P_1, P_2, C_p, \gamma = 1.4 ## ##...

So I'm reading that ice (solid) always has a liquid surface if it's surrounded by a gas. Does this mean every solid (e.g., my dining room table) also has a liquid surface because it's surrounded by gas? It doesn't seem to have a liquid surface. :-/ If something sublimes it skips this phase so I...

Homework Statement A glass tube filled with air at room temperature is 1.54m long. The tube is closed on one end, and open on the other. When submerging the open end in water, the water in the tube rises by 0.14m. How much of the tube is above the water's surface? The correct answer is 0.40m...

For a gas generator like this, I have seen diagrams of the thistle tube in the water, below the other tube or above it, where is it meant to be? Also, where is the other tube meant to be because I have seen it in multiple positions. Thanks!

A quote from wikipedia: "At sufficiently low temperatures, free protons will bind to electrons. However, the character of such bound protons does not change, and they remain protons. A fast proton moving through matter will slow by interactions with electrons and nuclei, until it is captured by...

Homework Statement Two well-insulated rigid tanks of equal volume, tank A and tank B, are connected via a valve. Tank A is initially empty. Tank B has 2 kg of Argon at 350 K and 5000 kPa. The valve is opened and the Argon fills both tanks. State 2 is the final equilibrium state. The temperature...

My question is very basic concerning gas lasers. I wanted clarification that a gas laser gets its light from a cell containing only that gas with a few other constituents and a high voltage being applied to it. Basically I'd like to understand what is happening with a CO2 laser and why it...

If there are any experimentalists out there maybe you could help? I need to bubble gas through a liquid at ~80 mL/min is there a specific instrument designed to do this? I'm assuming it's some sort of pump, what would it be called in a chemistry lab? Thank you for any suggestions / help.

I used a tub for my hemorrhoid. I learned the archimedes principle which the buoyant force is equal to the mass of water displaced. The tub was filled with water 4/5. I accidently farted in a tub and suddenly the water flew into the hole which is located on the top of tub.does the fart gas...

Good evening, I'm an undergraduate astrophysics student currently doing research, and I wanted to get the opinion of some knowledgable chemists about a particular reaction my professor and I wish to emulate. Using a specific type of laser (Nd: YAG, for example), I'd like to mimic something...

Homework Statement Does the specific heat of an ideal gas depend on the temperature only or does it depend on molecular weight and structure ? or both ? Homework Equations PV=mRT , Cp -Cv=R The Attempt at a Solution One of my teachers said it depends only on temperature and the other said...

My brother is working on an LNG transporter and I would like to know how much energy there is in the LNG the ship is transporting, here is the info I got : Methane ISO6974 99.8518 mole% ethane 0.0137 mole% propane 0.0000 mole% i-butane 0.0000 mole% n-butane 0.0000 mole% i-Pentane 0.0000 mole%...

Homework Statement A welder using a tank of volume 8.00×10−2 m^3 fills it with oxygen (with a molar mass of 32.0 g/mol ) at a gauge pressure of 3.10×105 Pa and temperature of 38.9 ∘C. The tank has a small leak, and in time some of the oxygen leaks out. On a day when the temperature is 23.0 ∘C...

Homework Statement Homework Equations no The Attempt at a Solution no Since the problem asks how much work was done by OR on the gas, I did not understand why the book's answer is 162 J instead ±81 J that I've found. (sorry my bad english) Sorry, the correct question on the problem is how...

Precisely how does a vacuum pump take the gas, let's just assume air, out of a container?

I got into a discussion with a friend about the risk of second hand smoke, so I did some research and found the statistical data that is some what puzzling. according to what I have read passive smoke kills 7,000 people each year. Radon gas is responsible for 21,000 deaths per year. There are...

We know that the average occupation number cannot be negative for all systems and chemical potential must be negative in Ideal Bose Gas. This fact leads us to arrive a conclusion for fugacity which is related by chemical potential, as I quoted below: The restriction of the fugacity to the...

Homework Statement Hello, I just need help figuring out how to calculate the work done by the gas molecules for my physics homework :) Formula given: W=Px∆V (W=work, P=pressure, and V=volume) What I know: So my calculated volume is 1.7x10^-22m^3. Pressure=0.25 A t m (atmospheric pressure) I...

So I have a question regarding the specific heat capacities in thermodynamics. In general the specific heat capacities for a gas (or gas mixture in thermo-chemical equilibrium) can be expressed as, ## c_p = \left(\frac{\partial h}{\partial T}\right)_p \qquad \text{and} \qquad c_v=...

Homework Statement Consider a rectangular isolated(non-conducting) chamber as shown below. The chamber is divided into three compartments. The wall separating A and B has negligible mass, no friction and is conducting, while the wall separating B and C has negligible mass and friction and is...

Homework Statement Why can’t transverse waves travel through a gas or liquid? Homework EquationsThe Attempt at a Solution I understand that transverse waves require rigid medium through which to transfer their energy so they can travel through solids. I'll just accept that transverse waves can...

Homework Statement A 1.00 mol sample of an ideal diatomic gas at a pressure of 1.00 atm and temperature of 420 K undergoes a process in which its pressure increases linearly with temperature. The final temperature and pressure are 720 K and 1.60 atm. Determine the work done by this gas during...

what is reason for preferring platinum in micro-heater fabrication in the case of a gas sensor ? my understanding is that it is because of its stability in different chemical environments. Please comment if there are any other reasons

I have what seems like a straight forward question, but am unable to find a formula. The question originates from my previous topic which was trolled: https://www.physicsforums.com/threads/blowing-up-a-balloon-using-centrifugal-force.848892/ Basically I have a 1.5m hollow length of 10mm tube...

Hi everybody; today I was reading some problems about a metal and the electrons of the conduction band; the man who solved them used the mass of the electron as effective mass (m*). I don't know why he did that; I have investigated but I don't have fount an explanation. Can somebody please...

Homework Statement A sample containing 3.65 mol of a monatomic ideal gas is heated from 289K to 458K, and the entropy remains constant. If the initial volume of the sample was 0.0980m^2, by what factor did the pressure increase or decrease during this process? Homework EquationsThe Attempt at...

Homework Statement Temperature, pressure and volume measurements performed on 1 kg of a simple compressible substance in three stable equilibrium states yield the following results. State 1 (T1=400 C , V1= 0,10 m3, P1=3 MPa) State 2 (T1=400 C , V1= 0,08 m3, P1=3,5 MPa) State 3 (T1=500 C , V1=...

I've read in my texts that the there are two kinds of Molar Specific Heat Capacities for gases: 1. Molar Specific Heat Capacity at constant Volume ----- ##C_v## 2. Molar Specific Heat Capacity at constant Pressure ---- ##C_p## And in case of Constant temperature there is no point in...

I was going through a worked example in book "Concepts in Thermal Physics" by S.J. Blundell and K.M.Blundell. The example talks about measuring viscosity of a gas between two coaxial cylinders. Homework Statement Two vertical coaxial cylinders. Outer cylinders is rotated by a motor at constant...