Questions tagged [kinetic-theory-of-gases]

Questions about the assumptions, equations, and properties of gases derived from kinetic theory. For questions pertaining to rates of reactions, please use the kinetics tag instead.

1
vote
0answers
17 views

What are the limitations of the Theorem of Corresponding states?

I recently came across the theorem of corresponding states, which states that all gases exhibit the same compressibility factor, under same reduced pressure and temperature (and also the critical ...
-3
votes
0answers
32 views

Ap chemistry question 2019 gasses [on hold]

I had a question about 4d. I explained that a few gas particles would change phase into liquid and that particles in liquid phase do not increase the pressure so the pressure will decrease. Is my ...
-3
votes
0answers
22 views

Gas-Liquid equilibriums [closed]

Will a few $\ce{CO2}$ particles at high temperature (300 °C) turn into liquid phase because of the gas liquid equilibrium or will none of them be in liquid phase.
1
vote
0answers
63 views

How to derive the compressibility factor for a van der Waals gas?

So as far as I know, $$Z=\frac{p_\mathrm{r}V_\mathrm{r}}{nRT},$$ where $\mathrm{r}$ denotes the subscript for real. Solving it for a van der Waals gas gave me the following result, $$Z=1+\frac{p_\...
2
votes
2answers
134 views

Compressibility Factor Of Gases

In the general equation of the compressibility factor $Z$, we define $Z$ as $$Z=\frac{pV}{nRT}$$ Here, what is $p$? Is it $p_\text{real}$ or $p_\text{ideal}$? Also, what is $V$? $V_\text{real}$ or $V_\...
1
vote
2answers
66 views

What happens to the pressure of gas when only one molecule of it is placed in a very large container?

We say that pressure due to gas is constant throughout the container. Pressure is created by molecules present in it. When there are many molecules I agree that they can apply the same pressure all ...
3
votes
1answer
44 views

The distance that CO2 molecules travel in the air before they collide with each other

Well the title covers most. But further at 410 ppm, 1 atm and 23 °C. I believe they call it the mean free path of CO2-CO2 collisions. So not just the mean free path of CO2 in air colliding with every ...
0
votes
1answer
63 views

Why 1 mole of H2 occupied the same volume occupied by 1 mole of O2?

I'm asking a question about the volume occupied by gasses in standard temperature and pressure. My textbook said that a mole of any gas occupies 22.4 L at standard temperature and pressure. But ...
1
vote
0answers
16 views

Finding Pressure of M in a Charge Exchange

Ar (RE = 15.5 eV) is the reagent gas in a charge exchange experiment. If Ar+ reacts with anisole with a rate constant of 2.26x10-10cm3 molecules-1/s-1 and 65% of the Ar ions react in 25 milliseconds, ...
0
votes
2answers
176 views

The respective speed of five molecules are 2, 1.5, 1.6, 1.6 and 1.2 km/s. The most probable speed in km/s will be?

The respective speed of five molecules are 2, 1.5, 1.6, 1.6 and 1.2 km/s. The most probable speed in km/s will be? 1. 2 2. 1.58 3. 1.6 4. 1.31 I think the answer should be 1.6 km/h but the ...
0
votes
1answer
71 views

What is the radius of the atoms? [closed]

In a recipient there is an unknown monoatomic gas that occupies a volume of $\pu{230 cm3}$, at $\pu{300 K}$ and $\pu{1 atm}$. It is known that the atoms occupy a volume of $2\times10^{-4}$. Find the ...
2
votes
1answer
45 views

Shape of the container and the number of possible energy states

A question came up when studying the formula for calculating the total number of possible energy states of a particle within a container. Why is the number of possible energy states independent of ...
2
votes
0answers
44 views

Feasibility of application of Boyle's law in the case of varying number of moles [closed]

While reading up on ideal gases and the Boyle's law, I encountered a question in my textbook wherein a balloon was being filled with helium (assumed to be ideal) till it was just about to burst. The ...
1
vote
0answers
61 views

How does degree of freedom work [closed]

I understand that the degree of freedom is the number of ways in which a molecule can acquire energy. I don't want you to explain the definition, but I want to see how it works. Please explain how is ...
3
votes
3answers
600 views

Equalization of pressure in heat exchanger

I was solving numericals on Kinetic Theory of Gases when I came across this question Two closed vessel of equal volume contain air at 105 kPa, 300 K and are connected through narrow tube. If one of ...
0
votes
1answer
113 views

Does the translational part of internal energy mean the kinetic energy of the gas?

Internal energy of an ideal gas consists of energy due to translational, rotational , vibrational etc. This line from WP says: In thermodynamics, the internal energy of a system is the energy ...
2
votes
1answer
147 views

Why do gases coexist as liquid and vapour?

I have having difficulty in understanding the liquefaction of gases.In the graph of isotherms of $\ce{CO2}$ I cannot understand how can gas coexist as liquid and vapour under area of $\mathrm{XCEBY}$....
0
votes
1answer
44 views

Why are moles used in the ideal gas law and not simply mass?

The crux of my question is, why is just the amount of particles included in $PV=nRT$ and there is nothing to account for the mass of the individual molecules? Or is mass accounted for in temperature, ...
0
votes
1answer
140 views

Interpreting straight lines in a graph of isotherms of carbon dioxide

I am having difficulty in understanding pressure-volume graphs of $\ce{CO2}$ at different temperatures which describes liquefaction of $\ce{CO2}$. I know that at the critical temperature of $\pu{31.1^...
2
votes
3answers
424 views

What is the term used as correction for attractive forces in the Van der Waals Equation?

I have seen a question in my textbook which is little bit confusing, The term that corrects for attractive forces present in real gas in van der Waal equation is (i) ${nb}$ (ii) $\frac{an^2}...
1
vote
1answer
103 views

Dependency of rate of diffusion on mean free path and velocity of molecules? [duplicate]

What is the dependency of rate of diffusion ( Graham's law) on mean free path, molecular size , average velocity, collision frequency and pressure? I have searched everywhere on internet but just ...
2
votes
0answers
46 views

How was it possible to accurately measure the mass of gases in the 19th century?

I have seen periodic tables of Mendeleev (1834-1907) and Newland (1837-1898) in which masses of gases such as oxygen and nitrogen were shown. I don't think there were instruments to measure mass of ...
-2
votes
1answer
71 views

Is there a better model than the Kinetic Theory of Gases [closed]

I'm looking for a better relationship between the Kinetic energy of a gas and it's Temperature, and also how they vary with gravity (not altitude, just gravity!). So is there a model better than the ...
5
votes
2answers
167 views

Finite probability from discrete distribution and zero probability from continuous distribution in Maxwell-Boltzmann statistics

I have difficulty understanding a certain concept with the derivation of the Maxwell-Boltzmann distribution $f(v)$ function from Boltzmann statistics. The derivation starts with the Boltzmann ...
1
vote
1answer
67 views

Does the probability function for a molecule to have energy in a certain mode depend on the minimum required quantum energy level of that mode?

I understand that the probability density for a particular velocity v+dv in one dimension for a molecule in a system is: $$f(v) = \sqrt{\frac{m}{2\pi k_B T}} \cdot e^{\frac{-mv^2}{2k_B T}}$$ I'm ...
1
vote
0answers
89 views

Effusion rate 1.4 times faster SO2(g)

How do I solve this- Which diatomic gas would effuse at a rate that is 1.4 times faster than the rate at which so2(g) effuses at any given temperature? This is high school chemistry. I did: (using ...
0
votes
1answer
163 views

van der Waals equation for deviation of gases from ideal behavior

$(P + an^2/V^2)(V - nb) = nRT$ I understand that the term $nb$ is subtracted from the volume term as the available volume for the gas molecules to move around decreases in the case of a real gas ...
2
votes
2answers
125 views

Volume of gas in containers

If gases occupy all the volume in a container then how can we define 'volume percent' as all different gases will have same volume?
0
votes
1answer
1k views

What is the relation between absolute temperature, and rates of diffusion and effusion of a gas?

According to Graham's diffusion law, rate of diffusion is directly proportional to square root of temperature but rate of effusion is inversely proportional to square root of temperature. Why is this ...
-1
votes
1answer
193 views

Effect on rate of diffusion in addition of an inert gas

What will be the effect on the rate of diffusion on addition of an inert gas to the gaseous mixture? I think the rate of diffusion should increase as the addition of extra gas will increase the ...
1
vote
0answers
41 views

Is the kinetic gas equation valid for non-cubical containers?

I have seen the derivation of the following equation for a cubical container with $N$ molecules. $$PV = \frac 13 mNu^2 $$ How is this equation valid even for spherical container or any other non ...
2
votes
2answers
100 views

Why is the speed of ideal gases mass dependent while the kinetic energy is not?

The rms speed of an ideal gas is $v_{\text{rms}}$ = $\sqrt{\frac{3RT}{M} }$ and the kinetic energy is $E_\text{k} = \frac32RT$. From this, it is concluded that the speed is mass dependent, while the ...
-1
votes
1answer
50 views

How to determine if pressure surpasses capacity with the van der Waals equation of state?

I have to decide whether a $\pu{20 L}$ container with $\pu{0.8 kg}$ ethane can withstand the pressure at $\pu{373.15 K}$. The following information is given: \begin{align} b &= \pu{6.448x10^-2 ...
2
votes
1answer
6k views

Is Internal Energy = (3/2)nRT for a ideal monoatomic gas?

Internal Energy is a state variable and its value at a particular state cannot be measured; only the change in internal energy can be measured. So how come we write that $$U=\frac32nRT$$ where $U$ = ...
5
votes
1answer
9k views

Calculating Compressibility factor from the Van der Waals' Gas equation

So this problem has been bugging me for a long time. According to Wikipedia the compressibility factor $Z$ is defined as the ratio of the volume occupied by a real gas divided by the volume occupied ...
3
votes
2answers
997 views

Kinetic energy of molecules in liquid state?

My book (book link) has this question: The kinetic energy of molecules at constant temperature in gaseous state is: more than those in the liquid state less than those in the liquid ...
-3
votes
1answer
41 views

Volume of gas in a system [closed]

With two closed vessels of equal volume that are connected to each other through a narrow tube, the temperature of one of the containers is increased. Why does the final volume of gas inside each ...
1
vote
0answers
48 views

An elementary question worth asking [closed]

We all know that an atom starts moving faster when it's heated.But actually atom is not some new thing itself in the sense that it is just a bunch of electrons and protons. So, I think that same ...
4
votes
1answer
596 views

Why do gases need to be cooled to liquefy/solidify?

My book states: Gases do not liquify on compression only, although molecules come close to each other and Weak forces operate at a maximum. Why is it that we cannot just keep on compressing gas ...
4
votes
1answer
177 views

Estimation of pressure and kinetic energy density of stellar interior using kinetic theory of gases

In Physical Chemistry we are working a problem that is confusing. We started by calculating the pressure half way to the centre of the sun assuming that the interior consisted of ionized hydrogen ...
-2
votes
1answer
726 views

Maximum in Maxwell–Boltzmann distribution [closed]

I need to find the maximum of the Maxwell–Boltzmann distribution $$P(v) = \left(\frac{m}{2\pi kT}\right)^{3/2}4\pi v^2 \exp{\left(-\frac{mv^2}{2kT}\right)}$$ I know that occurs when $\mathrm dP(v)/\...
2
votes
0answers
101 views

Volume of gas produced in a reaction

Is it correct to say that 'x' litres of a gas were produced in a reaction, calculating x using the ideal gas equation, since the volume occupied by a gas is taken to be the volume of the container it ...
2
votes
1answer
906 views

Chemical reactions in plasma state

I am wondering about chemical reactions when the reactants are in a plasma state. Consider hydrogen and oxygen. Heated, these would react to form water. If hydrogen and oxygen plasma were combined, ...
2
votes
1answer
616 views

Speed distribution of lighter vs heavier gases

I cannot understand why the range of molecular speed is not always wider for a lighter gas as compared to a heavier gas . If the same energy is supplied to both gases then wouldn't the molecular ...
2
votes
2answers
22k views

How to calculate the final temperature of a gas when it undergoes adiabatic expansion?

The question is as follows: A sample of $\pu{4.0 moles}$ of a gas ($C_{v,m} = \pu{21 J mol-1 K-1}$) has an initial pressure of $\pu{304.4 kPa}$ and an initial volume of $\pu{20 dm3}$ at $\pu{270 K}$...
6
votes
2answers
663 views

Is this a violation of Equipartition theorem?

My book has a question asking to calculate average kinetic energy of the molecules in 8g of methane. By the Equipartition theorem, I calculated that energy: 1. per molecule per degree of freedom = $(...
0
votes
1answer
93 views

What is the value of the gas constant derived from the kinetic model of gases?

I used this resource (http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1151&context=physicskatz) to derive the ideal gas law from the kinetic model of gases: $$PV=n(2/3)N_oT$$ with T ...
0
votes
1answer
38 views

Direction of gas molecules in kinetic model of gases?

So when learning about the kinetic model of gases, my teacher said that in a volume $A*v_{x}*\Delta t$, exactly half the molecules will have a velocity component of $v_x$ and the other half will have ...
0
votes
2answers
278 views

is avogadro's law for the same gas?

Avogadro's law is V1/n1 = v2/n2 - volume and number of moles are directly proportional. My question is - can this law apply to two different gases - for example, Hydrogen with volume v1 and number n1,...
-3
votes
1answer
34 views

How fast do it take a gas kinetic energy to react to intense heat? [closed]

Let's say I have argon gas in a small container. And opened the flap of the container and stuck a rode that was around 2000-3000 Degrees Fahrenheit, And was only in there for a millisecond. How long ...