# 0.15 Reaction rates

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## Foundation

We will assume an understanding of the postulates of the Kinetic Molecular Theory and of the energetics of chemical reactions. We will also assume an understanding of phaseequilibrium and reaction equilibrium, including the temperature dependence of equilibrium constants.

## Goals

We have carefully examined the observation that chemical reactions come to equilibrium. Depending on thereaction, the equilibrium conditions can be such that there is a mixture of reactants and products, or virtually all products, orvirtually all reactants. We have not considered the time scale for the reaction to achieve these conditions, however. In many cases,the speed of the reaction might be of more interest than the final equilibrium conditions of the reaction. Some reactions proceed soslowly towards equilibrium as to appear not to occur at all. For example, metallic iron will eventually oxidize in the presence ofaqueous salt solutions, but the time is sufficiently long for this process that we can reasonably expect to build a boat out of iron.On the other hand, some reactions may be so rapid as to pose a hazard. For example, hydrogen gas will react with oxygen gas sorapidly as to cause an explosion. In addition, the time scale for a reaction can depend very strongly on the amounts of reactants andtheir temperature.

In this concept development study, we seek an understanding of the rates of chemical reactions. We will defineand measure reaction rates and develop a quantitative analysis of the dependence of the reaction rates on the conditions of thereaction, including concentration of reactants and temperature. This quantitative analysis will provide us insight into the processof a chemical reaction and thus lead us to develop a model to provide an understanding of the significance of reactantconcentration and temperature.

We will find that many reactions proceed quite simply, with reactant molecules colliding and exchanging atoms. Inother cases, we will find that the process of reaction can be quite complicated, involving many molecular collisions and rearrangementsleading from reactant molecules to product molecules. The rate of the chemical reaction is determined by these steps.

## Observation 1: reaction rates

We begin by considering a fairly simple reaction on a rather elegant molecule. One oxidized form ofbuckminsterfullerene ${C}_{60}$ is ${C}_{60}{O}_{3}$ , with a three oxygen bridge as shown in .

${C}_{60}{O}_{3}$ is prepared from ${C}_{60}$ dissolved in toluene solution at temperatures of $0°C$ or below. When the solution is warmed, ${C}_{60}{O}_{3}$ decomposes, releasing ${O}_{2}$ and creating ${C}_{60}O$ in a reaction which goes essentially to completion. We can actually watch this process happen in time by measuring the amount of lightof a specific frequency absorbed by the ${C}_{60}{O}_{3}$ molecules, called the absorbance . The absorbance is proportional to the concentration of the ${C}_{60}{O}_{3}$ in the toluene solution, so observing the absorbance as a function of time is essentially the same as observing the concentration as afunction of time. One such set of data is given in , and is shown in the graph in .

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
Do somebody tell me a best nano engineering book for beginners?
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
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
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
types of nano material
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
what is nano technology
what is system testing?
preparation of nanomaterial
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
what is system testing
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
how did you get the value of 2000N.What calculations are needed to arrive at it
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