Questions tagged [gas]

This tag is for questions relating to "gas", one of the four fundamental states of matter (the others being solid, liquid, and plasma). Gases follow certain laws known as the gas laws. These laws tell us about the behavior of gases i.e., the values and relations of temperature, pressure and volume etc.

Filter by
Sorted by
Tagged with
1
vote
1answer
30 views

Would gas inside of non-compressible material be affected by pressure in the deep ocean? [duplicate]

I was thinking about the pressure of the deep ocean and was curious if gasses inside of a non-compressible container would experience the extreme pressures associated with great depth. I'm sort of ...
8
votes
7answers
1k views

What is the counter-force to suction force?

I've been thinking about air pressure and vacuums recently and a (for me at least) interesting question came to mind: If there is an area with lower pressure than the surrounding air, the air ...
1
vote
0answers
18 views

Is it possible to create gases with high rotational temperature and low translation temperature?

Has anyone been able to take a monoatomic gas (ex: Helium) and put it in a state where the individual atoms are moving at extremely low velocity (low "translational" temperature) but the ...
0
votes
0answers
17 views

Will a contained fluid and a fixed, perfectly consistent source of disturbance eventually settle into a pattern, or will it be chaotic?

Imagine you have a large room, which is completely sealed, and a cordless fan in the corner that constantly blows at a low speed. Disregarding effects like heat transfer from outside, minute physical ...
0
votes
1answer
26 views

Can pre-compressed refrigerant or other gas be effectively used for air-conditioning? [closed]

Is it feasible to store a very large quantity of precompressed gas that can later be used for cooling the coils in an air-conditioner? For example, an aerosol can such as a deodorant has a cooling ...
3
votes
1answer
186 views

Is there any substance whose vapor-liquid coexistence area appears leaned?

The usual substance whose vapor-liquid coexistence area appears like that shown in following Fig.1 My question is: is there any substance whose vapor-liquid coexistence area looks leaned, i.e., $V_{...
0
votes
2answers
34 views

Would the relationship of pressure and volume of gas change if the gas type is changed?

Question. There is an experiment investigating how a gas's occupying volume changes when its exerting pressure alters. As a result, a graph of pressure versus volume has been plotted, which is half of ...
1
vote
1answer
60 views

Integral for the configurational part of the canonical partition function (classical monatomic gas)

S. Salinas, Introduction to Statistical Physics (p. 111) computes the following integral for the configurational part of the canonical partition function of a classical monatomic gas (volume $V$, ...
2
votes
2answers
258 views

Equation of motion of a gas's center of mass due to heating

So here's a pretty basic question that I don't know how to solve within standard thermodynamics. Let's say I have a container with a gas in it. I transfer heat, $Q$, to the gas from the bottom of the ...
0
votes
2answers
41 views

Latent heat and change of state

If 1kg of water at 100℃ is supplied with less amount of heat energy than the latent heat of vaporisation,what will happen to it?Does part of it undergo phase change while the rest remain same?Or the ...
1
vote
0answers
66 views

Is the van der Waals fluid viscous?

The van der Waals equation of states is well known: $$\tag{1} p(\rho) = \frac{a \rho}{1 - b \rho} - c\rho^2. $$ What is the energy-momentum tensor of this gas, considered as a fluid? Is it the simple ...
3
votes
2answers
254 views

Is a detailed absorption spectrum available for carbon dioxide from 300-1100nm?

I believe that carbon dioxide does not absorb light in the visible region, but is a spectrum available somewhere online that shows this as a fact? As in a straight horizontal line at 100% transmission?...
0
votes
0answers
9 views

How to distinguish a Continuous running Xenon lamp from a low power flash tube? How to experimentallyfind out the power rating of it?

Photos: https://www.ebay.com/itm/124318383096 https://www.ebay.com/itm/154066136022 I checked online but did not find useful information. What are some ways to know what capacitor bank voltage and ...
0
votes
0answers
40 views

Why doesn't earth have a hydrogen atmosphere if hydrogen's thermal velocity is 1.75 km/s - less than 1/6th of earth's escape velocity? [duplicate]

I have read that in order to retain a gas, a planet's escape velocity must be at least six times the thermal velocity of that gas (I understand that this is just an approximation of the Maxwell ...
1
vote
3answers
60 views

Modelling gas concentration in a room with exhaust fan [closed]

Asumme a ceramic kiln is placed inside a room of volume $V \ m^3$. There is an exhaust fan installed in the room to extract all the kiln fumes to the outside of the room (and building) with a constant ...
1
vote
0answers
41 views

The model of a free particle in a box as an approximation for the translational motion of a particle in a gas

According to the book Introduction to Physical Gas Dynamics (starting from page 120), the translational motion of a particle in a gas in thermal equilibrium may be approximated by a free particle in a ...
3
votes
1answer
87 views

Does the gravitational force of a gas change with its temperature? And why?

I have read the paragraph below, somewhere- Consider a sphere filled with gas. It will generate a spherically symmetric gravitational field outside itself, of strength proportional to the total mass. ...
10
votes
6answers
2k views

Why can’t you feel the collision of each air molecule?

The molecules in a gas move very fast because of its thermal motion. But why can’t we feel the hit of each of the fast gas molecules?
0
votes
2answers
39 views

Principle of how refrigerator works: how is temperature dropping but pressure is not?

I'm taking "Physics of the everyday" on Brilliant. Here is the diagram of how refrigerators work: Regarding the cooling step: After exiting the compressor, this gas cools to room ...
0
votes
0answers
62 views

How does Gravity compare to the Van der Waals Forces?

Van der Waals forces' is a general term used to define the attraction of intermolecular forces between molecules. There are two kinds of Van der Waals forces: weak London Dispersion Forces and ...
-1
votes
1answer
39 views

Is steam just a combination of small waterdrops and air?

I have seen a question here about steam. It made me unsure about the nature of steam. Isn't steam a hot white cloud of water vapor? Is it just water in a gas state, so that its temperature can be ...
0
votes
1answer
34 views

Question about “suction” , and overall physics, in this Whoosh Bottle Experiment

https://www.chemedx.org/blog/there-more-whoosh-bottle So this is a pretty standard "Whoosh Bottle" experiment, but with a twist, in that he covers his hand (palm) on the bottle after the ...
0
votes
2answers
34 views

Non-popping bubbles

I used a compressed air can to clean my laptop's keyboard and speakers. After that procedure I noticed there're small bubbles in the holes of the speakers. I've tried to pop them with a thin brush and ...
2
votes
1answer
41 views

What is the meaning of grain opacity and why does it affect the formation time of gas giants?

While doing research for my presentation on the formation of gas giants, more specifically the "core-accretion model", I have been stumbling across the term "grain opacity" and don'...
2
votes
3answers
66 views

How many water molecules should I put together before I can tell If it's liquid, gas or Solid?

How many water molecules should I put together before I can tell If it's liquid, gas, or Solid? I know, there isn't any clear boundary that says that you have to put $50$ molecules or $100$ ...
0
votes
1answer
19 views

Doubt about the idea of pressure exerted by a gas’ visualisation

In an educational video on derivation of the formula (3/2)PV=Kinetic energy of the gas, it was assumed that 1/3 of the particles are linearly translating along the three axes of the coordinate plane ...
1
vote
2answers
98 views

How does gravitational potential energy pertain to a single gas particle escaping the atmosphere?

What's the effective difference between a helium molecule moving at 11.18 km/s and one moving at 11.2 km/s at the edge of the atmosphere? Is the idea that, with a particle moving just below the ...
0
votes
2answers
24 views

Is there a gas present in the Martian atmosphere similar to hydrogen?

is there a gas present in the Martian atmosphere which could be extracted to inflate a balloon with sufficient lift to support an instrument platform for low altitude reconnaissance.
1
vote
0answers
37 views

Is there any problem in this task? (molecular formula of a gas inside a cylinder) [closed]

I got this task: A cylinder of volume V₁ = 2 L filled with gas of mass m = 7.48 g at T = 10 °C and under pressure P₁ = 2 bar Calculate the amount of gas substance in the cylinder. Infer the molecular ...
1
vote
1answer
19 views

How do turbine engines improve compression ratio?

As I have learnt from the Venturi tube that Pressure is inversely proportional to velocity. When a general aircraft is flying at say Mach 0.8 and at the same time there is a pressure decrease with ...
1
vote
1answer
42 views

What is meant by “is driven by collisions between its atoms and molecules”?" in NASA's statement?

"The behavior of a dense atmosphere is driven by collisions between its atoms and molecules." says https://www.nasa.gov/content/goddard/ladee-lunar-neon. It seems to me that a gas's behavior ...
15
votes
3answers
4k views

What does “rarely” mean in NASA's statement: “technically referred to as an exosphere because it’s so thin, its atoms rarely collide.”?

The following statement is from this article: The behavior of a dense atmosphere is driven by collisions between its atoms and molecules. However, the moon's atmosphere is technically referred to as ...
0
votes
0answers
9 views

What is the state of the art gas concentration measurement technics, especialy for $\rm CO_2$?

Reviewing different sensors, I could find: NDIR (Nondispersive infrared sensor) is a simple spectroscopic sensor often used as a gas detector. It is non-dispersive in the fact that no dispersive ...
1
vote
1answer
51 views

Graphs of thermodynamic transformations

I received a question from one of my students of a high school (17 years old) with reference to a graph of a Clayperon-plane. Suppose that it is the one shown in the figure. From state $A \to B$ is ...
2
votes
1answer
44 views

Deformation of a sphere

I am currently building a computational model for a simulation of a rover landing on the surface of mars. As part of the assignment I need to model airbags being used to cushion the fall. (Assuming ...
0
votes
1answer
54 views

I am having difficulty understanting this question from thermodynamics [closed]

According to above question the process is isothermal. Hence the product PV is always constant. Since Volume is decreasing, hence Pressure must increase. Hence Work done by gas is calculated by ...
0
votes
1answer
64 views

Relighting a candle from its smoke, and being burned?

Having been extinguished, a candle can be relit from the resulting trail of smoke, even from meters away. However despite this apparently high level of heat, paper, bystanders, etc… are never ...
0
votes
2answers
62 views

Why is volume of gas independent of its molecule size?

According to the ideal gas law: $pv = nRt $ My question is, why is the volume $v$ independent of the volume of individual components of the gas, i.e. molecules? As the sizes of individual molecules ...
0
votes
1answer
30 views

Pressure on the walls of a balloon

Is the atmospheric pressure the only pressure acting on the exterior walls of a balloon keep the air/gas inside the ballon at equilibrium? Or the walls of balloon being elastic, do exert pressure on ...
0
votes
3answers
62 views

Why change in entropy in reversible adiabatic process is zero?

In the adiabatic expansion step of carnot cycle, adiabatic change is carried out in an insulated system. In this process volume gets increased but entropy remains constant. Now if we look at the ...
2
votes
1answer
29 views

Barometric formula with variable gravity

Recently, I have wondered about what would be the atmospheric pressure as a function of altitude in a planet that only consists of gas. The equation that does just that is the barometric formula (see ...
0
votes
1answer
32 views

How Joule-Thomson coefficient is measured experimentally?

I am reading about Joule-Thomson effect but I can't understand how the respective coefficient $μ$ can be measured experimentally. The Joule-Thomson coefficient is defined as: $$μ=\left(\frac{\partial ...
1
vote
1answer
47 views

Is underproved bread dough an example of the Young–Laplace equation?

I was watching minuteEarth's video on Young-Laplace with regards to RDS in premature babies when I made the connection that bread dough, as a foam with many curved pockets of gas, would necessarily be ...
0
votes
2answers
32 views

How Do Accelerated Electrons Between Electrodes Cause Ionization of Gas Molecules?

Due to small number of free electrons in gases these electrons are accelerated in electric field which creates collisions with gas molecules causing an ionization of molecules. I am not sure how do ...
1
vote
1answer
29 views

Gas regulator pressure

When I open the gas regulator, it pushes the pin and depress the valve in the cylinder which releases the gas out (am I right on this?). If that is the case, is gas released even when there is no hose ...
0
votes
1answer
25 views

Is there any website or method to calculate the refractive index of gases like $\rm CO_2$ in the mid IR?

I want to know the complex refractive index of some gases like CO2, CH4, C2H6 .. etc in the mid infrared. Is there any website, software or a method to know them?
0
votes
1answer
26 views

Liquid nitrous oxide released from gas cylinder

Say you have liquid nitrous oxide in a standard gas cylinder (about 55 bar) at room temperature. Normally the cylinder sits upright and gas is released via valve. Now let's assume you released liquid ...
0
votes
1answer
16 views

What pressure does liquid nitrous oxide need at -45°C?

What pressure does liquid nitrous oxide need at -45°C to remain liquid? How can I calculate it's pressure required for other temperatures?
-2
votes
1answer
43 views

Is it possible to visualize water vapour with a low-cost instrument or setup in a lab? [closed]

Would infrared or laser be of any help? In a lab setting.
0
votes
0answers
18 views

Examples of Flows with Constant Velocity and Pressure

I am looking through a paper and there is a section where they derive field quantities (temperature and heat flux) for a gas flow which has vanishing (or at least constant) velocity and pressure ...

1
2 3 4 5
11