Kinetic theory Definition and 145 Threads

Homework Statement (Pathria 6.11) Considering the loss of translational energy suffered by the molecules of a gas on reflection from a receding wall, derive, for a quasi-static adiabatic expansion of an ideal nonrelativistic gas, the well-known relation ##PV^{\gamma} = \text{const.}## where...

I have a question about deriving the equation of kinetic theory of ideal gas - PV=1/3 Nmcr2, where N is number of atoms, cr is root mean square of atom speed and m is mass of one atom. In deriving the equation, many textbooks consider the total rate of change of momentum within a certain time...

Are there any good books to understand the BBKGY equations of kinetic theory?

http://en.wikipedia.org/wiki/Kinetic_theory#Pressure_and_kinetic_energy Based on the derivation for P in the above link, one of the early steps was: Δt = 2L/vx which is fine since it is analyzing one specific wall of the container, but then in the next step: F = Δp/Δt = mvx2/L And...

Hi guys, I'm studying the Kinetic Theory of gases from Pauli's book Vol. 3. Here he describes a section on the Mean free path, where the probability of two particles with speed v and v' colliding is described as:What is f(v,v') here? Is it the velocity distribution function? If so, isn't it...

Hello! It's been around two months since I started to learn about the knetic theory of ideal gases. But I haven't managed to completely understand it. What I don't understand is how we derive the formula for the presure that the gas molecules exerts on a wall's surface. Here's what I've...

Homework Statement The average kinetic energy of a nitrogen molecule at temperature 25c is _____ . Select the correct answer. 1)5*10^(-21) J 2)3*10^(-20) J 3)1*10^(-20) J 4)9*10^(-20) J 5)8*10^(-21) J (i guess they are all wrong ) Homework Equations KE=3/2 K.TThe Attempt at a Solution...

My textbook says that the forces of intermolecular attraction between gas molecules are very weak due to large intermolecular spaces between them , that's why they're negligible , Does this have a relation with "force is inversely proportional to the square of distance " (again , I don't know...

Question: In the following link I'm concerned with only pages 1 and 2. I'm wondering if there is a typo or an error of some kind. I feel like there is some inconsistency to what the author refers to as \upsilon, \theta, and \phi. The only angle shown in the diagram is \upsilon, which is the...

The kinetic theory states that the gas molecules are randomly colliding with each other and with the wall of the container with high speed.The area of each molecule is very less and as they are moving with high speed,they exert great force. since the pressure is force/area , the pressure should...

Are all collisions between fluid molecules perfectly elastic? I was under the impression that they were not, but now I'm not sure if I'm wrong or not...

Hi everbody! This has been bugging me for quite some time now, so I would be forever grateful and challenge you to think about this. According to the Wikipedia (and phyiscs textbooks), " Since the assumption is that the particles move in random directions, we will have to...

Homework Statement The temperature of an ideal gas (M=28kg/mole) has increased 14K by adding 29J of heat at a constant pressure. To cool the gas back to the initaial temperature 20.7J of heat is extracted from the gas at a constant volume. Find the mass of the gas. Homework Equations...

I am trying to find a description of sound waves and speed of sound in gases using Kinetic Theory. I mean to derive the sound waves in a medium like gas , composed of molecules moving and colliding as Kinetic Theory describes. The origin of the sound wave, as our experience shows, is the...

Homework Statement Find the mean speed of the molecules escaping through a hole of area \sigma. The vessel has volume V and the molecules mass m.Homework Equations dN_w^e = \frac {dA}{4V} w \frac{dN_w}{dw} dw w is the speed. dN_w = \frac {4N}{\sqrt \pi c^3} w^2 \exp {\frac {-w^2}{c^2} }dw...

Say you compress a closed container full of gas (you reduce its volume). You are not holding the pressure constant or anything. As you do this, the temperature increases, but why? My best guesses are: - some of the energy you use for pressing down on the container is transferred to heat...

Hello, I am reading through my textbook and cannot wrap this idea around my head yet Basically, when a molecule hits the wall of the container, it is reflected back. ΔP = -mv_x -mv_x = -2mv_x = FΔt_collision Then they say the collision occurs every 2d/v_x because that's the time it...

kinetic theory Homework Statement Hi all, I have 1 question that I hope to clarify: Regarding the kinetic theory: it states, that the kinetic energy of ideal gas is 3/2KBT. However, it is stated in my textbook and other sites that kinetic energy of ideal gas is 3/2nRT. The 2 equations...

So far I have found a kinetic-theory explanation of the Boyle's Law, Charle's Law, and Pressure-Temperature Law. For example, for the pressure-temperature law: increasing the temperature of a gas while holding the volume constant causes the gas molecules to collide more frequently with the...

Question: A square frame of side 10cm rests on a table. Confined within the frame are 500 ants, each of mass 0.001g. The ants rush about randomly with constant speed 0.02m/s, colliding with each other and with the walls. Assuming the collisions are perfectly elastic, calculate for force on each...

The kinetic theory of gas state that p=(1/3)(N)(m)(u^2)/(V). In one step of its derivative related to change of momentum and force given to the wall (Refer to Cubic Container and molecule movement in x,y,z axes in attachment), the equation is given by: change in momentum / time = force...

Homework Statement When deriving the Ideal Gas Formula from the Kinetic Theory of Gases, we assumed that the gas molecules made perfectly elastic collisions with the walls of the container. This assumption is not necessary as long as the walls are at the same temperature as the gas. Why? The...

I have reviewed recently the demonstration of the formula for the pressure of a gas by using the kinetic theory and it seems that there is a terrible flaw in it, which I will describe below. Can anyone comment on it, please? In all textbooks, the pressure of a gas is proven to be proportional...

Can someone explain me this theory ? and how to use the equation please I have this in my notes but I don't understand :( Average (translational) Kinetic Energy per molecule is E= 3/2kT The same, per mole, is U = 3/2 * R* T

For a reaction to occur, we assume that two particles collide, have sufficient energy to react, and are oriented appropriately...or so I've read. The first one is straight forward. The second two I have questions about. For convenience, let's say A + B-> AB is what we're looking at. This...

Homework Statement A quantity of helium gas is held in a square box 1 m length. The measured macroscopic pressure of the gas is 1000 Pa. An atom of helium makes 500 collisions per second with the wall of the container traveling at an average velocity perpendicular to a wall of a container...

Homework Statement I have this assignment from my chemistry teacher and it asks to relate electroplating with the kinetic theory? I don't really understand how the kinetic theory has anything to do with redox, or other chemistry applications. Homework Equations The Attempt at a...

The main book we'll be using will be Serway's, but I want a different book that's more focused on the mathematics formulation of thermodynamics and kinetic theory of gases, and not so simple as Serway's. The other 3 books in the discipline's bibliography are: • M.W. Zemansky and R. H...

Homework Statement An ideal gas in a cylinder occupies a volume of 0.065 m3 at room temperature (T = 293 K). The gas is confined by a piston with a weight of 100 N and an area of 0.65 m2. The pressure above the piston is equal to one atmosphere (atm = 1.013x10^5 Pa). The piston is free to move...

Hi I would like to ask is there any relation between compressibility factor of gases and temperature? My textbook says that it always increases with increase in temperature but doesn't explains how? I know that on increases the temperature it is harder for molecules to show attractive...

If the aleatory speed of a gas rises with pressure and temperature and there is not an apparent limit for these two, what prevents the particles to reach the speed of light? thank you

Homework Statement An ideal gas is kept in a container of constant volume. The pressure of the gas is also kept constant (a) If the number of molecules in the gas is doubled, does the rms speed increase, decrease, or stay the same? (b) If the initial rms speed is 1300 , what is the final...

i have a question that I cannot solve; Show that the rms velocity of a sodium atom moving in a vacuum chamber at 300 kelvin is about 570 metres per second pV=nRT and 3pV=Nm<c^2>

Homework Statement Find the rms speed in air at 0.0°C and 1.00 atm of (a) the N2 molecules (b) the O2 molecules, and (c) the CO2 molecules. Homework Equations vrms = square root of 3kT/m The Attempt at a Solution (a). 28.0u x (1.66 x 10^-27) = 4.68 x 10^-26 1.5 x (1.38 x 10-23...

My (first) question is - is a Maxwell-Boltzmann distribution function a "cumulative distribution function."?

I have some questions on kinetic theory of gases: kinetic theory assumes that the inter molecular force of attraction between two molecules of a gas is negligible. This assumption applies to the condition that the said gas is either at low pressure or at high temperature. This means, when the...

Hello. There is something I don't understand about the momentum tensor t_{ik}=nm\int f(|v|) v_iv_k of an ideal gas with an isotropic velocities distribution where n is the number of molecules per unit volume and m is the mass of a molecule. Since the the velocity distrubution is isotropic...

Kinetic THeory Question - URGENT! Homework Statement Ok so we've been asked to show that viscosity n = 1/3 p <v> lambda where lambda is the mean free path, p density of gas and <v> mean speed of particles in a gas I've done this part.. Then the question says that in 1660 boyle did an...

Homework Statement The figure shows the initial state of the gas in an insulated cylinder. The gas is ideal and it is given that, Cp/Cv = 1.5. The insulated piston by the help of an external agent is slowly shifted to the right such that the piston divides the cylinder in the ratio 1 : 3...

Homework Statement An ideal monoatomic gas is confined in a cylinder by a spring-loaded piston of cross section 8 x 10-3m2. Initially the gas is at 300K and occupies a volume of 2.4 x 10-3 m3 and the spring is in its relaxed state. The gas is heated by a smalll heater until the piston moves out...

Question:Dalton’s law of partial pressures states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of gases making up the mixture. Give a convincing argument for this law based on the kinetic theory of gases. Answer to this question from the book I...

Hey I'm studying the Kinetic Theory of gases and although it's in a chemistry book it employs physics concepts ergo I have come here to ask you nice people :biggrin: The 5th point is where I have a problem, the rest is just information for you. I am assuming a particle is in a cube (ideal...

Homework Statement A flat plate is orbiting at an altitude of 250 km around the earth, at an angle of attack &Beta;=45 degrees. Assume that the atmosphere is composed of only atomic oxygen which reflect from the surface diffusely. Calculate the lift and drag if it has an area of 10 M2...

Homework Statement A sample of an ideal gas is at a temperature of 320 K. The rms molecular speed at this temperature is measured as 1631 m/s. Calculate the mass of a molecule of this gas Homework Equations rms velocity , u = √(3RT/M ) The Attempt at a Solution Given u = 1631 m...

Homework Statement A sample of an ideal gas is both compressed and cooled. The given variables for the gas are: P1 = 90.0 kPa, V1 = 0.0800 m3, V2 = 0.0400 m3, T1 = 300. K, T2 = 260. K. Calculate the final pressure. Homework Equations PV=nRT P1 V1 /T1 = P2V2 / T2 The Attempt...

Homework Statement At standard temperature and pressure (273 K and 1 atmosphere), oxygen has a mass density () of 1.43 kg/m3. The molecular mass (m) of oxygen is 32 u. Calculate the number (n) of molecules in one cm3 of oxygen. (Round to three significant figures.) Homework Equations...

Homework Statement A brass plug is to be placed in a ring made of iron. At room temperature (20°C), the diameter of the plug is 8.764 cm and that of the inside of the ring is 8.754 cm. They must both be brought to what common temperature in order to fit? Homework Equations Change in...

Question 1: The mean speed for escaping molecules from a hole is 1.88*(k*T)/m)^1/2 (Eq.1) The mean speed for molecules in the Maxwell-Boltz Distribution is 1.596*((k*T)/m)^1/2 (Eq.2 If you were to calculate molecular flux for an ideal gas, which expression would you use? In my...

Homework Statement Consider a mixture of oxygen and hydrogen kept at room temperature.As compared to a hydrogen molecule an oxygen molecule hits the wall- (a) with greater average speed (b)with smaller average speed (c)with greater average kinetic energy (d)with smaller average kinetic...

Homework Statement A square box contain He at 25C. If the atoms collide with wall perpendicularly (90 degrees) at rate of 4.0E22 times/s, calculate pressure and force exerted on wall given area of wall 100cm^2 and speed of atoms =600 m/s Homework Equations PV=Nmv^2 The Attempt at a...