Gases Definition and 476 Threads

Homework Statement In a proper laboratory setup for collecting a gas by water displacement, which of these gases could NOT be collected over H2O because of its solubility? A. CO2 B. NO C. O2 D. NH3 E. CH4 Homework Equations - The Attempt at a Solution I know E is definitely wrong because its...

Homework Statement One mole of oxygen at 27°C and at one atmospheric pressure is enclosed in a vessel. Assuming the molecules to be moving with Vrms, find the number of collisions per second which the molecules make with 1 m2 area of the vessel wall. Homework Equations vrms = √(3RT/M) PV = nRT...

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...

Homework Statement I have been tasked with designing a feasible experiment to determine the ration between 2 vessels. I think i have a way that works on paper. Homework Equations pV = nRT and the conservation of mass. The Attempt at a Solution 1.Start with 2 vessels of unknown volume x and y...

Homework Statement [/B] 5,00 moles of graphite and 5,00 moles of oxygen gas are stored in a metal bottle. The temperature is raised until the graphite starts burning. The burning produces a mixture of CO and CO2 gases in the vessel. After the temperature had returned to it's original value...

Homework Statement I have the following task: Homework EquationsThe Attempt at a Solution I already managed to calculate Delta Um, but how do I calculate Q und W. Can I use the equations for the isothermic expansion for ideal gases, even if this are Van-der-Waals Gases?

Homework Statement Homework EquationsThe Attempt at a Solution I chose 1&2, but all three are correct. I thought for a constant pressure, if temperature is doubled, then the volume would doubled too? As P=V/T ?

Ar STP Every gas occupies same volume of 22.4 L but how it can be because every gas molecule has different size right? So they should occupy different volumes right? If I'm wrong at any point then please correct me

You have a capillary with a stream of water vapor flowing through. Inside the capillary argon gas is also flowing (in the same direction) with a flow rate of 3 L/min. How high of a flow rate can the water vapor have before it starts condensing on the walls? Flow is laminar and the system is at...

Homework Statement 96 grams of oxygen and 50 grams of hydrogen gas occupy separate, equal sections of 200 liter tank. The divide is removed and the gases are allowed to mix and react with each other. Temperature is kept constant at 120 degrees celsius 2. Homework Equations [/B] b) find the...

Intuitively I always thought He was more expensive than Ar as a shielding gas. But I was reading this book about Heat Exchanger Design & it has this quote that claims "Argon is costlier than Helium" (Link below; see Bullet Point...

Hello chaps, I'm trying to calculate absorption coefficients of gases at moderate temperatures ie ranges in which diatomic gases (such as N2 orO2) are partially disassociated or ionised, therefore including molecular bands as well as continuum. Can anyone recommend some suitable reading...

I've read that gas molecules do not have any attractions or regulations between them... So why do different gases have different densities?

Are there any research or paper regarding electromagnetic effect on gases. For example does H2 gas physically move under electromagnetic field?

There are claims or at least assumptions that: "upon approaching "critical point" pure gases become super compressible. You could compress them many times without pressure increase and store like this if you maintain exact temperature and pressure needed. It opens possibility to superdense gas...

What would happen if all of the empty space of the universe from the small to the vast, were replaced with the gases that make the Earth's atmosphere while neglecting gravity from any massive object?

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...

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...

Homework Statement Figure shows two rigid vessels A and B, each of volume 200 cm3 containing an ideal gas (Cv = 12.5 J/mol-K). The vessels are connected to a manometer tube containing mercury. The pressure in both the vessels is 75 cm of mercury and the temperature is 300 . (b) 5.0 J of heat...

Homework Statement A closed organ pipe resonates in its fundamental mode at a frequency of ##200Hz## in ##O_2## at a certain temperature. If the pipe contains 2 moles of ##O_2## and 3 moles of ##O_3## are now added to it, then what will be the fundamental frequency of same pipe at same...

Homework Statement A tube which is open at both ends is immersed in a beaker containing mercury. The top end which comes out of the mercury level is now sealed and then the tube is raised by some height such that some part still remains inside the beaker. The mercury inside the tube rises...

Homework Statement A system is made up of two halves. In one there's 10kg neon gas with the temperature ##20 \circ##C, in the other 10kg nitrogen gas with the temperature ##100 \circ## C. Suppose the septum is removed so that thermodynamic equilibrium may appear and the gases mix. Calculate...

What type of gas would change the colour of an electron beam as the speed of the electrons increases?

Hi I was wondering if someone could tell me what kind of gases I could expect to see using an IR receiver between the wavelengths of 110 and 330 nm. As well as this id love to know what kind of glass could be used in order to not interfere with the actual results. Thanks a million

hello I have hot gases with steam (water) inside how do I separate it ? without cooling it magnetic field can help? ultrasound? something else? thanks!

I don't understand how Delta(U) = Cvdelta(T) is always true for Ideal Gases...Shouldn't this only be true for constant volume processes? Yet it seems to be used even when a gas is expanding or being compressed... Any ideas...Thanks in advance.

Hi, I am struggling with a particular point on the derivation of the kinetic theory of gases. Between 5mins and 6mins 30seconds of the video below they discuss how to get a value for the average of the squared velocities of the molecules in the gas. The bit I don't get is why they divide by 'N'...

I'm curious about that do gases emit infrared radiation the same way as solid bodies do? If yes, how can it be detected like an infrared camera does?

Homework Statement "Show that particles hitting a plane boundary have traveled a distance 2λ/3 perpendicular to the plane since their last collision, on average."Homework Equations (Root mean path squared) <x> = 2^(.5)λ λ = ( 2^(.5) * n * sigma )^(-1) ANSWER: The Attempt at a Solution...

My teacher constantly stresses that 10 moles of a gas going to 11 moles of a gas will ALWAYS cause an increase in entropy (ΔS>0). But why? For example (I know that O2 shouldn't technically be a liquid, but just as an example): 2H2O(g)⇔H2O(g)+(3/2)O2(l)+2H2 It seems iffy to me. We go from...

Hello I'm reading Feynman here: http://www.feynmanlectures.caltech.edu/I_39.html I'm having problems understanding how he turns equation 39.11 into 39.12. He does some U -> dU trick and he turns: U=PV/(\gamma-1) into dU=(PdV+VdP)/(\gamma-1) I don't understand this intuitively. Any help...

I am trying to calculate the speed of sound in a mixture of 2 gases like oxygen an ozone. First step: I calculated ##\gamma_{eff}## of the mixture by first calculate the ##C_V## of mixture by using a formula $$C_V=\frac{n_1C_1 + n_2C_2}{n_1+n_2}$$ Step 2: in the formula $$v=\sqrt{\frac{\gamma...

Systems A, B, and C are classical gases (not necessarily ideal), each with the same number of molecules N ( or same number of moles n if you prefer), where N is constant. We can measure pressures and volumes Pa,Va ; Pb,Vb ; and Pc,Vc for each system. When A and B are in thermal equilibrium, our...

Systems A, B, and C are classical gases (not necessarily ideal), each with the same number of molecules N ( or same number of moles n if you prefer), where N is constant. We can measure pressures and volumes Pa,Va ; Pb,Vb ; and Pc,Vc for each system. When A and B are in thermal equilibrium, our...

Is there a creditable chart out there - on the dielectric constant of gases? What is the dielectric constant of Sulfur hexafluoride (SF6) compared to other gases or other gases in a vacuum? Thank You

Homework Statement The exhaust gases from a natural gas-fired central heating boiler leave the boiler at a temperature of 70 deg C. The oxygen content of the exhaust gases is 9% by volume (dry). The rate of energy input (Gross calorific value) to the boiler from natural gas is 16kW. The gross...

Say there is a chair soaked in gasoline. If someone is to walk in the room the smell is immediate if the chair was lit on fire the liquid gasoline would ignite the chair. However, what about the particles that constitute the smell of it? Why don't they ignite as well? What is the nature of the...

Hi! I saw something on my lecture notes that I don't really understand. It reads "Rare gases have filled s and p-sub-shells, which leads to a spherically symmetric charge distribution. Since electrons are indistinguishable they take on a common wavefunction. The point is that this results in a...

Hey guys, Im currently looking for a way to calculate the energy loss of a particle in a gas. This will help me to understand deposition processes better. The particles I am looking at are heavy, uncharged ones (e.g. metal atoms). Stopping power is not a viable concept without charge, and Bethe...

I had an exam question where I had to find the volume taken up by a gas consisting of 32 grams of oxygen and 4 grams of helium at STP conditions. I ended up getting a supposedly incorrect answer of about 44.8 liters by finding the volume of both gases and adding them together. However, my...

Homework Statement An audience of 2750 fills a concert hall of volume 35000 m3. If there were no ventilation, by how much would the temperature of the air rise over a period of 2.0 h due to the metabolism of the people (70 W/person)? Homework Equations Q= nCvΔT Cv= (3/2) R The Attempt at a...

Homework Statement A stiff and isolated vessel is divided into 2 halves by an isolator divider. in each half there is a gas (i am not told if it's the same) with presures and temperatures T1, P1 and T2, P2. the divider is removed. Apply the first law of thermodynamics and draw conclusions...

Homework Statement If the flue gases exiting the boiler are used to preheat the water fed to the boiler from a temperature of 28 C to 90 C and assuming: • a mean specific heat capacity for water over this temperature range to be 4.2 kJ kg–1 K–1 a mean molar heat capacity for the flue...

One of the assumptions of Kinetic Theory states that: A gas is a substance composed of many particles flying about randomly, colliding with one another and with the walls of the container. My instructor mention that we might be required to Know, state, and apply this theory to one of newtoms...

In a recent class, my instructor covered the Kinetic Theory of gases. My question is in regard to the theory which states 1) The size of the individual molecues in a gas are so small that their volumes can be considered negligible. The instructor then mentioned that the paticles in the gas can...

Homework Statement 1.00mole of nitrogen (N2) gas and 1.00mole of argon (Ar) gas are in separate, equal-sized, insulated containers at the same temperature. The containers are then connected and the gases (assumed ideal) allowed to mix. A) What is the change in entropy of the system? B) What is...

I'm interested in predicting the index of refraction of atmospheric air and several nonpolar gases at room temperature for pressures of 1 atm - 0 atm. I'm not really sure where to get started. I have found the relation n=\sqrt{1+\frac{3AP}{RT}} but I don't really get where it comes from. Well...

Hi, this is my first post on here. My question relates to adiabatic cooling/heating of a gas. I am trying to grasp the idea conceptually rather than being able to explain it mathematically per se... When gas escapes rapidly from a pressurised cylinder the rapid expansion of the gas is...

Homework Statement A closed, insulated cylinder is divided into two equal parts by a piston. One compartment contains Nitrogen at T=300K, P1=5bar, the other Carbon Dioxide at T=300K, P2=20bar. The cylinder contents then reach mechanical and thermal equilibrium. 1. Assuming that the gases...

Is it possible to manipulate a noble gas to produce any line in its emission spectrum for a ? For example, argon produces blue but it also has several lines of red, can one force the argon to emit the red bands?