0.1 The kinetic molecular theory  (Page 4/7)

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Based on our observations and deductions, we take as the postulates of our model:

• A gas consists of individual particles in constant and random motion.
• The individual particles have negligible volume.
• The individual particles do not attract or repel one another in any way.
• The pressure of the gas is due entirely to the force of the collisions of the gas particles with the walls of thecontainer.

This model is the Kinetic Molecular Theory of Gases . We now look to see where this model leads.

Derivation of boyle's law from the kinetic molecular theory

To calculate the pressure generated by a gas of $N$ particles contained in a volume $V$ , we must calculate the force $F$ generated per area $A$ by collisions against the walls. To do so, we begin by determining the number of collisions of particles withthe walls. The number of collisions we observe depends on how long we wait. Let's measure the pressure for a period of time $\Delta (t)$ and calculate how many collisions occur in that time period. For a particle to collide with the wall within the time $\Delta (t)$ , it must start close enough to the wall to impact it in that period of time. If the particle is travelling with speed $v$ , then the particle must be within a distance $v\Delta (t)$ of the wall to hit it. Also, if we are measuring the force exerted on the area $A$ , the particle must hit that area to contribute to our pressure measurement.

For simplicity, we can view the situation pictorially here . We assume that the particles are moving perpendicularly to the walls. (This is clearly not true. However,very importantly, this assumption is only made to simplify the mathematics of our derivation. It is not necessary to make thisassumption, and the result is not affected by the assumption.) In order for a particle to hit the area $A$ marked on the wall, it must lie within the cylinder shown, which is of length $v\Delta (t)$ and cross-sectional area $A$ . The volume of this cylinder is $Av\Delta (t)$ , so the number of particles contained in the cylinder is $×((Av\Delta (t))(), \frac{N}{V})$ .

Not all of these particles collide with the wall during $\Delta (t)$ , though, since most of them are not traveling in the correct direction. There are six directions for aparticle to go, corresponding to plus or minus direction in x, y, or z. Therefore, on average, the fraction of particles moving inthe correct direction should be $\frac{1}{6}$ , assuming as we have that the motions are all random. Therefore, the numberof particles which impact the wall in time $\Delta (t)$ is $×((Av\Delta (t))(), \frac{N}{6V})$ .

The force generated by these collisions is calculated from Newton’s equation, $F=ma$ , where $a$ is the acceleration due to the collisions. Consider first a singleparticle moving directly perpendicular to a wall with velocity $v$ as in . We note that, when the particle collides with the wall, the wall does not move, so the collision must generally conservethe energy of the particle. Then the particle’s velocity after the collision must be $-v$ , since it is now travelling in the opposite direction. Thus, the change in velocity of the particle inthis one collision is $2v$ . Multiplying by the number of collisions in $\Delta (t)$ and dividing by the time $\Delta (t)$ , we find that the total acceleration (change in velocity per time) is $\frac{2ANv^{2}}{6V}$ , and the force imparted on the wall due collisions is found bymultiplying by the mass of the particles:

Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
how did you get the value of 2000N.What calculations are needed to arrive at it
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