Physical and chemical laws describing the properties and behavior of gases.

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Endothermic Conversion of Liquid to Gas

When a liquid (in my case I used butane) under high pressure is released into the air, it becomes gaseous, and the container seems to get colder. Why is it that turning a liquid to a gas requires ...
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Calculate the final pressure, the composition of the mixture, and the partial pressures of the components?

A tank contains methane at 1000 psia and 140 F. Another tank of equal volume contains ethane at 500 psia and 140 F. The two tanks are connected, the gases are allowed to mix, and the temperature is ...
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How do I calculate the new volume of an ideal gas upon temperature change [on hold]

The problem asks a gas temperature of 14 degrees C, and a volume of 4.5L. If the Temperature is raised to 29 degrees C and the pressure is not changed, what is the new volume of the gas? The ...
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How does composition of air affect vapor saturation limit?

Suppose we hold temperature, pressure, and gas composition (say, a standard atmosphere) constant. Then we know that if we allow the water content of the air to vary it can range between 0 and some ...
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How to calculate the amount of gas in a compressed cylinder

I am trying to calculate a cost per hour use of a gas we buy in a cylinder. The details I have been working with are: Gas used CP-grade N2 material number: 110628-L can Gas: ...
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Gas Stoichiometry - where is my mistake in dealing with this problem?

A $20.0$-L nickel container was charged with $0.500$ atm of xenon gas and $1.50$ atm of fluorine gas at $400$ $^{\circ}$C. The xenon and fluorine react to form xenon tetrafluoride. What mass of xenon ...
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What causes spray cans to get cooler when shaken?

I've been searching the web for this phenomenon and surprisingly I found only one post about it. And the reply to this question about canned air begins with words: I don't know about the shaking ...
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Can covalently bonded hydrocarbons be influenced by a magnetic field?

I am doing a University project on Magnetically Assisted Combustion and am curious to know more about how magnetic fields may or may not affect gases such as butane and propane. I think I am right ...
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Hydrogen and Helium ideal gas behavior in room temperature

Which one of hydrogen and helium behaves more like ideal gas in room temperature... I thought hydrogen gas would show more ideal behavior in room temperature because it has lighter mass (less no of ...
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49 views

How quickly does sulfur hexafluoride mix with the atmosphere?

A common science demonstration is to float a "boat" on sulfur hexafluoride. How long would the sulfur hexafluoride stay in the container (in the experiment linked above) if the container were to be ...
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Raoult's Law explained with thermodynamics/ free energy

I got some confusion going on with this explanation of Raoult's Law. This is what my book say: Because the ideal solution has a higher entropy than the pure solvent, the energy of a vapor ...
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Why does small value of van der Waals gas constant “b” ensure easier liquefication?

Larger value of b signifies that the size of the molecules is larger and hence the forces acting should become larger due to increased surface area.This should ensure easier liquefication. But my book ...
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How can you achieve negative pressure?

Pressure is the magnitude (absolute value) of the force over the area, so how can that result in a negative value for pressure as would happen in certain circumstances?
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Why does the graph of compressibility factor(z) vs pressure increase after reaching the minimum?

I understand why it decreases for most of the gases but i cannot understand why it increases after reaching a certain minimum.
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How to calculate to number of moles using the ideal gas law [closed]

Which quantity of N2 gas has a volume of 11.2 liters at STP? Select one: 1.00 moles 2.00 moles 14.0 grams 28.0 grams
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how to calculate the gas volume per purge when I change the cylinder?

I have some gas cylinders in a gas cabinet. Every time I change the cylinder, I use N2(100%v/v, 60L/min) to purge the residue gas in the pipe to a local scrubber. I want to know how many gases I ...
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Determining [CO2] of a sample in ppm

I have 20mL gas samples and I need to determine the [CO2] in ppm. I have a Li-Cor 6200 with a closed loop, so essentially I will inject a volume of gas into the loop and the change in the output is ...
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What happens if you make a gas of magnetic particles [closed]

I was reading todays SMBC which asked what happens if you make a gas of magnetic particles So what does happen if you make a gas of magnetic particles?
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How much gas is inside a pressurised gas cylinder?

Given a 19kg Liquid Petroleum Gas (LPG) cylinder, with this specification: LPG inside the cylinder weighs 19kg. The internal volume of the cylinder is ...
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Applying Avagadro's law: the relationship between moles and volume of a gas

If 2.4 moles of gas fill a volume of 175 mL, what volume, in mL, will 5.4 additional moles of gas fill? This was a quiz question which I got wrong the first attempt, and I think I got it right this ...
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How does adding Argon to this reaction affect the number of moles of each reactant? [duplicate]

We have this reaction: At equilibrium, we have 5.3 moles of $\ce{H2}$ and 5.4 moles of $\ce{HI}$. At some later time, 1.7 moles of Argon (the question states that this is an inertial gas and does ...
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Concentration of expanding gases

At $t = 0$ we have 10 moles of $\ce{NO2}$ and 10 moles of $\ce{N2O4}$ satisfying this reaction in a 0.75 liter tank (the barrier is closed at this time): $$\ce{N2O4 <=> 2NO2}$$ The system is ...
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Real gas expansion

Will a real gas occupy all the space available for it? An ideal gas will expand to fill its container but will a real gas? And what are the changes in a real gas when it expands freely against a ...
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Which gas makes Orange juice bottles swell?

I forgot a bottle of 1L Orange Juice (100% orange juice with pulp) in the fridge for about a week, the bottle was previously open so air got inside as well. After a week the bottle got inflated and ...
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What allows all 3 states of H₂O to be present at the same time?

How is it possible for there to be a glacier floating on water but under clouds? Depending on the temperature, shouldn't there only be one state of water?
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Permanent Balloon?

Is it possible to create a container for helium that it can't permeate through, like a permanent balloon? Or, if not, what kind of material would have the lowest permeability for that application? I ...
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Producing low Density Gas in Room Temp

Does anybody know two liquids or a solid and a liquid that can react to produce a gas less dense than air ( or similar ) in room temperature . This question is intended to make a chemical induced ...
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537 views

Are there any magnetic particles that are safe to inhale?

In medicine, there is an (old?) experiment where a subject is asked to inhale radioactive Xenon gas, and radiation counters are placed at different positions near the lungs. Using this experiment, it ...
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What is the density of compressed natural gas used for natural gas vehicles

I would like to know the density of the compressed natural gas used for natural gas vehicles in order to complete the formula in the following StackExchange post: ...
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Helium gas expand isobaric isothermal

If 4 mol helium gas expand against constant pressure in isothermal process. How can calculate w? Is it w=-nrtLn(v2:v1) as define by isothermal or is it w=-p(v2-v1)as define from isobaric? Also, is ...
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Why does a container in which a match burning cause suction?

As you see in picture a burning match in a container causes suction and this is a Traditional Therapeutic method to relive bone pain. What is the reason? I think it should be related to gas ...
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What determines humidity limit / dew point of the air? - Why can air only hold a certain amount of water?

From Wikipedia: The dew point is the temperature at which the water vapor in a sample of air at constant barometric pressure condenses into liquid water at the same rate at which it evaporates. At ...
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Collection of gas over water

When you collect a gas over water, you have to account for the mixed in water vapor by subtracting the room pressure from water vapor pressure. However, why do you not do something similar for volume, ...
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Prepare 1 liter of 28% NH3(aq) solution from 1 gal of %10 NH3(aq)

I have one gallon of commercial, surfactant free, ammonium hydroxide solution that I would like to use to prepare a concentrated solution. I have two options as I see it, and I am still getting into ...
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In order to be a gas does the pressure exerted by the gas has to be more than the atmospheric pressure?

In order to be a gas does the pressure exerted by the gas has to be more than the atmospheric pressure? Really simple, I think yes to this question but teacher says no. So what is your view into this? ...
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Is there any graph that depicts the deviation of real gases from Charle's law?

I am looking for a graph that shows the basic deviation of a gas from the Charle's law. The graph should be for different values of constant pressures.This would help me evaluate how gases follow ...
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Reducing NOx with Ammonia. Practical in a gasifier?

Sorry if this is an outright stupid question. I am no chemist. For nitric oxide: $\ce{2{NH_{3}} + 2 NO -> 2 {N_{2}} + {H_{2}} + 2{H_{2}O}}$ For nitrogen dioxide: $\ce{2{NH_{3}} + 2{NO_{2}} ...
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Why two ( or more) gases have proportional volumes at constant pressure and temp.? (Avogadro's Law)

I am in real confusion over Avogadro's Law.. In some of the problems I did on gas laws, there are the number of moles of the gas, the temperature. and the pressure. And it expects me to find the ...
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Is this the correct equation for the mean free path?

$\lambda=\frac{KT}{\sigma p}$ is the equation given in my textbook but everywhere else I look it is different. Is it wrong? The derivation is as follows: $$\lambda = \frac{v_{rel}}{z}$$ where ...
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How do derive the equation for relative velocity of gas molecules

The relative velocity is $$v_{rel}=\sqrt2v_{mean}$$ where $v_{mean}=(\frac{8KT}{\pi m})^{\frac12}$$$v_{rel}=(\frac{16KT}{\pi \frac m2})^{\frac12}$$ because the reduced mass of two of the same ...
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How to get the first step of the derivation of the Maxwell-Boltzmann distribution

To derive the Maxwell-Boltzmann distribution the first step requires the knowledge that the equation will take the form $$f(v)=Ke^{-\epsilon/ kT}$$ where $\epsilon$ is the sum of the kinetic energies ...
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Calculate the root-mean-squared speed of free electrons in the Sun's corona given pressure, temperature and mass of an electron

$m_\text{e}=9.1\times10^{-31}\ \mathrm{kg}$, $T=2\times10^{6}\ \mathrm{K}$ and $p=0.030\ \mathrm{Pa}$ the solution is given as: $5.4\times10^6\ \mathrm{ms^{-1}}$ but I got $9.5\times10^6\ ...
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Calculate the frequency so that the wavelength of sound in air would be equal to the mean free path in oxygen at 1.0 atm and 0ºC

Take the diameter of the oxygen molecule to be $3.0×10^{-10}$ m. Here's what I did: $$\lambda_{mfp}=\frac {K_BT}{\sigma p}$$ $p$ is pressure. Mfp stands for mean free path. ...
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Why can a gas only transmit sound waves whose wavelength is long compared with the mean free path?

Also when can this fact be useful? I don't really understand at all why this might be the case so any help would be appreciated.
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Percent composition, maybe?

I've attempted to solve this problem with percent composition, but it says the answer is wrong. Is it a PV=nRT problem, and if so, can I use the units as they are given? A 0.02867 g sample of gas ...
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A 4.00 L sample of gas is cooled from 67 °C to a temperature at which its volume is 2.60 L [closed]

A $4~\mathrm{L}$ sample of gas is cooled from $67~\mathrm{°C}$ to a temperature at which its volume is $2.6~\mathrm{L}$. What is this new temperature? Assume no change in pressure of the gas.
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Quick Stoich & Gasses

I have a quick question in Stoich and Gasses, I however could not get any far, any answer will be appreciated. Thank You. A sample of $\ce{Pb(NO3)2}$ is heated, yielding $\ce{O2, NO2\ gas,\ and\ ...
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Gas Stoichiometry & Ideal Gas Law

I need a little help with one of the problems below. Any help on the problem below will be appreciated. I don't want to sound like an idiot, I will also provide my work. Solid $\ce{NaHCO3}$ ...
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What will happen to the entropy and free energy of the gasses when the partition is removed?

Consider a container of volume $ 5.0$ L that is divided into two compartments of equal size. In the left compartment there is nitrogen at $1.0$ $atm$ and $25 °C$; in the right ...
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What conditions can cause a material to exist as a gas?

So my question is, how can something exist a gas. Is it when the pressure exerted by the gas is greater than the atmospheric pressure, then it is a gas? And also how do manometers work, how can you ...