Gas Definition and 1000 Threads

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...

Homework Statement Two moles of an ideal gas undergo a reversible isothermal expansion from 3.37×10−2m3 to 4.29×10−2m3 at a temperature of 29.6 ∘C. What is the change in entropy ΔS of the gas? Homework Equations pV=nRT The Attempt at a Solution W=∫V2V1pdV, I don't know how to use this...

Homework Statement If number of molecules in a closed container increases and it is kept at a constant tempurature, what happens to the pressure? I was confused because I thought if you add molecules the temputature would go up so keeping temputature a constant would have no affect on the...

In my book it is mentioned that piston effort along the line of stroke=(Force due to gas pressure)+(Inertia force) why we have to consider inertia force when it is a imaginary force which is considered only during non inertial frame? why we don't equate piston effort with gas force simple...

Homework Statement [/B] You are asked to calculate changes in internal energy, entropy, heat transferred and work done for each of the following process. Also you are asked to calculate "the latent heat for the isotherm in the figure". We know the a and b parameters which characterize the VdW...

Dear PF Forum, A: 1 mole O2 is roughly 32 grams? 1 mole ozone is roughly 48 grams? 1 mole CO2 is roughly 46 grams? Considering there are isotopes --------------------------------------------------------------- B: Do, at the same temperature and pressure, 1 mole CO2 and 1 mole O2 have the...

We feel a gas cylinder of cooking gas to be heavier if we lift it. But when a kid of 14 kg is lifted it feels a lot easier to lift him than lifting a cylinder of cooking gas weighing 14 kg. Is it because the pressure is low because of larger surface area of the kid?

Homework Statement A gas consisting of diatomic molecules that can rotate but not oscillate at a given range of temperatures expands adiabatically from pressure of 365Pa and volume of 70m3, doing 101J of work, while expanding to a final volume. What is its final PV (pressure volume) product...

Homework Statement I'm having a little trouble knowing when to use the ideal gas equations for entropy vs just the ones like this: (T2/T1)=(p2/p1)^((k-1)/k). I've noticed a pattern in the solutions for my homework( where you're finding isentropic efficiency of turbines and compressors) they...

Can anyone help on this problem encountered in gas chromatography: Two helium incoming gas lines A and B are connected together via a cross-shaped connector to two outlets C and D. All in and out lines are capillaries with diametre in the 0.1-1 mm range and lengths in the 10s of cm to 10s of...

Homework Statement One litre cylinder contains 1 mole of the ideal gas molecules having the average kinetic energy of 0.1eV. What is the total energy of this gas? Homework Equations W = K + U The Attempt at a Solution I figured because the cylinder is closed, no stated temperature change, or...

An ideal gas is compressed from a volume of Vi = 4.50 L to a volume of Vf = 3.00 L while in thermal contact with a heat reservoir at T = 295 K as in the figure below. During the compression process, the piston moves down a distance of d = 0.120 m under the action of an average external force of...

Dear PF Forum, Perhaps just yes/no answer would suffice. It's just out of curiosity and I can't find it on web. Or there are no answers :smile: Are there no noble gas compound? There are CH4, CO2, H2, O2 even O3 What about Helium, Argon, Neon? Are there really no compound with noble gas? If...

Homework Statement Questions are attached to this thread. Homework Equations P =mv (P is momentum) P = F/A (P is pressure) F = deltaP/delta t (P is momentum) The Attempt at a Solution I have managed to do questions a-e which I was very happy with but then moving onto the extension has made me...

https://www.physicsforums.com/attachment.php?attachmentid=20388&stc=1&d=1252066499When the partition removed, gas flows into the vacuum until all system has a uniform pressure. Now, is it possible to calculate the work? Let's say gas is not an ideal gas.(Freon 12) We know the volumes of both...

Qn : https://www.dropbox.com/s/dpcws9q4bjpzvtp/20151123_112037.jpg?dl=0 Why is option A and C wrong or correct? My attempted answer : A :A is plausible as if the piston is suddenly moved inwards, the gas molecules bounce off the piston at higher speeds Since Temp proportional to rms speed...

Homework Statement A gas has the following equations of state: P=\frac{U}{V} \,\,\,and \,\,\,T=3B\frac{U^{\frac{2}{3}}}{N^\frac{1}{3}V^\frac{1}{3}} where B is a positive constant. The system obeys the Nernst Postulate (S tends to zero as T tends to zero). The gas, at a initial temperature T_i...

Homework Statement I have the following task: Homework EquationsThe Attempt at a Solution But I don't understand how to solve it. Can somebody help me?[/B]

Hi, PF! I recently solved a problem from BSL which asked to analyze the following system used for determining the diffusivity of a binary mixture of gases. The left portion of the system, from the left bulb up to the stopcock at the middle of the tube, is filled with gas A. The right portion...

If you try to mix water and sand, the sand will mix around and eventually fall to the bottom. Sand and water can't make a solution, so they separate. However salt and water can make a solution, and they don't separate. If air is a mixture, why don't the gases separate? 1) So, pretty much what...