# 0.14 The kinetic molecular theory  (Page 7/8)

 Page 7 / 8

This view must be incomplete, though. Each individual particle might create a force proportional to 2v , but there are many particles hitting the wall, generating force, and our pressure gauge can’t possibly measure each tiny impact. So we need to take a different view. The total force generated by all of these tiny impacts will be determined by how many of these impacts there are. If the particles hit the wall more often, then the force will be higher. What determines how frequently the particles hit the wall? One factor should be how dense the particles are in the container. If there are a great many particles in a small volume, then many of the particles will be near the wall and collide with it. So, the frequency of the collisions of the particles with the walls of the container should be proportional to N/V , where N is the number of particles. A second factor would be how large the area of our pressure gauge is, A . A larger surface would be proportionally more collisions. A third factor would be how fast each particle is moving. Faster particles will create more frequent collisions with the wall. Each of these factors individually makes sense.

It is important to note that we have calculated the force of each tiny impact completely independently of the force of impact of any other particles. In fact, from our postulates, we have assumed that the individual particles have no effect on each other since they are so far apart from each other. This is why we can think of the force created by the gas as coming from a huge number of collisions, each one independent of all the others.

Putting these factors together, the frequency of collisions should be proportional to (N/V)Av . If we multiply this by the force of each collision, the total force impacted will be proportional to (2mv)(N/V)Av . Finally, the pressure is the force per area, so we wind up with the result that pressure P must be proportional to 2mv 2 N/V , or:

$\text{P}=\frac{\text{kNm}{\text{v}}^{\text{2}}}{\text{V}}$

( k is just some proportionality constant which we will need to find. We dropped the 2 since it is just a proportionality constant too.)

This result is very promising. It says that P is proportional to the number of particles N , which we could also write as the number of moles, n . That agrees with the Ideal Gas Law. It also says that P is inversely proportional to V . That also agrees with the Ideal Gas Law.

But there are two ways in which this equation looks different from the Ideal Gas Law. The first is that temperature is missing. This is because there was nothing in our postulates about temperature because we had no experiments which told us about how temperature affects molecular motion. The second is the appearance of the term mv 2 . From Physics, this is a very familiar expression, since the kinetic energy of a particle of mass m moving with speed v is ½ mv 2 . Notice that the pressure is proportional to the kinetic energy of the particles.

It is hard to solve the first concern. Temperature as we measured it in the previous Concept Development Study is an arbitrary measure of hot and cold. We simply observed that this measure turned out to the proportional to the pressure of an ideal gas. However, if we compare our equation to the Ideal Gas Law, we can make progress. The Ideal Gas Law tells us that pressure is proportional to n/V times the temperature T . Our equation above tells us that pressure is proportional to N/V times the kinetic energy of the particles, ½ mv 2 . This tells us that the temperature T is proportional to the kinetic energy of each particle, ½ mv 2 .

how can chip be made from sand
are nano particles real
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
no can't
Lohitha
where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
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Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
how did you get the value of 2000N.What calculations are needed to arrive at it
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