Message No. 11
Date: Friday, 11 February 2000
Time: 9:17 P.M.

Subject: Discussion No. 2 (Application of Chemical Kinetics)
From: Jelanie Serrano Astrologo

The industry that is using chemical kinetics is the 
Ammonia Synthesis Plant. In the manufacture of ammonia, operating 
pressures are very high (between 500 atm & 1000 atm). 

In the industrial process the NH3 never reaches its equilibrium 
value but is constantly removed from the reaction mixture in a 
continuous process.

The justification for the choice of high temperature is that the rate 
of NH3 production at room temperature is much too slow to be of any 
practical value. Even at 500 deg. C the rate is not fast enough, 
so chemist also add a catalyst consisting of iron plus oxides of 
potassium and aluminum to further enhance the rate.

Message No. 12
Date: Saturday, 12 February 2000
Time: 12:32 A.M.

Subject: Re: Discussion No. 2 (Application of Chemical Kinetics)
From: Mary Jane S. Gamboa

Scientists from California Institute of Technology are performing 
laser experiment on the femtosecond time scale 
(Dr. Ahmed H. Zewail, California Istitute of Technology)

"...transition states are very unstable and extremely short-lived they 
exist for incomprehensibly short periods of time before falling apart 
into product or back into reactants.  Reaserch in reaction dynamics 
requires the design of elaborate experiments to take "snapshots" of 
the transition state often using pulses of laser light that are 
extremely short in duration.

One of the first example of chemistry studied on the femtosecond time 
scale was dissociation of ICN by light, a so-called 
photofragmentation reaction:

     ICN(g)----[I...CN]----I(g)+CN(g)
          LIGHT ACTIVATED
                COMPLEX

The absorption of light by an ICN molecule excites the molecule and 
ultimately leads to breaking of the I-CN bond.  In the activated 
complex that results from the absorption of light, the iodine and 
carbon atoms are still within bonding distance of one another."

Message No. 13
Date: Saturday, 12 February 2000
Time: 8:47 P.M.

Subject: Re: Discussion No. 2 (Application of Chemical Kinetics)
From: Rea A. Lazarte

Hello everyone. My name is Rea A. Lazarte of EN1C. 

We all know that chemical kinetics is applied to most of the 
industries. Chemical kinetics is the area of chemistry that is 
concerned with the speeds, or rates, at which reactions occur.

One of the industries wherein chemical kinetics is applied is the 
Nitrogen Industries, of synthetic ammonia. This industry used or 
affected by one of the factors of the rate of chemical reaction, 
the presence of catalysts. 

"A catalysts is a substance that increases the rate of reaction 
without being consumed in the reaction. The speed of a chemical 
reaction is sometimes too slow to be economical, and a study of 
catalysis became necessary. It was not until Haber and Bosch 
showed that the rate of the hydrogenation of nitrogen to furnish 
ammonia could be greatly increased by contact with a catalyst of 
iron, promoted by small percentages of K2O and Al2O3, that the 
chemical rxn for the synthesis of ammonia became commercially 
economical.

Rate and catalysis of the rxn:
------------------------------
To be economical, the rate of this rxn must be increased, because 
hydrogen and nitrogen alone react very slowly. The basis of the 
commercial synthesis of ammonia rests upon an efficient catalyst to 
speed up the rxn rate to an economical degree. Such a catalyst has 
been found in iron, whose reaction rate is promoted by the addition 
of oxides of aluminum(3%) and potassium(1%). 

These promoters prevent sintering. Many reactions are known which 
occur as result of one reacting constituent combining w/ the catalyst 
to form the product of the catalytic reaction and to regenerate the 
catalyst. Thus, the nitride adduct is possible with iron atoms on the 
surfce of the ammonia catalyst. 
Iron seems the most satisfactory catalyst, it seems to lose its 
activity rapidly if heated to temperatures above 520 degrees Celsius. 
Catalysts are more active at a lower temperature.

A detailed mechanism for the catalysis leading to ammonia is as 
follows:
                N2 + 2Fe = 2Fe - N ads
                H2 + 2Fe = 2Fe - H ads
               N ads + H ads = NH ads
              NH ads + H ads = NH2 ads
             NH2 ads + H ads = NH3 ads
                       NH3 ads = NH3 desorb

Chemical kinetics is applied thru the manufacturing procedures:
American systems: ammonia synthesis are based on the reaction

   1/2N2(g) + 3/2H2(g)----NH3(g)  

[change in the enthalpy: 18 deg. C =-11kcal, 659 deg. C= -13.3kcal]

The rxn is exothermic. This may be broken into following sequences:
Ammonia synthesis gas is prepared by high-pressure catalytic reforming 
of hydrocarbon feed gas in the primary reformer with superheated steam,
and the secondary reformer with air to furnish nitrogen.

CO is converted by the catalytic iron oxide shift conversion with H2O.

CO2 is removed by a reactivated hot K2CO3 solution wash.

The 3:1 hydrogen-nitrogen mixture, freed of its CO, is raised to the 
full compression of 150 to 200 atm and mixed with the recompressed, 
recirculated gases. The gases are then passed to the water secondary 
heat exchanger and ammonia refrigerator and separator for removal of 
residual ammonia.

In the ammonia converter the gases are raised in a countercurrent heat 
exchanger to the reaction temperature and caused to react in the 
presence of the catalyst, after which they are cooled and most of the 
ammonia liquefied.

A portion of the gas is purged to prevent undue accumulation of 
diluents, such as methane or argon and the rest is recompressed for 
circulation.

The purge gas is conducted to the primary reformer."

Message No. 14
Date: Sunday, 13 February 2000
Time: 9:23 P.M.

Subject: Re: Discussion No. 2 (Application of Chemical Kinetics)
From: Fred Charles Diaz Ea

Hello Everyone I am Fred Charles D. Ea of EN1C.
 
From what I have learned, chemical kinetics is used in the making of 
pesticides and the fast production of software like in IBM software.  
There is a research going on to speed up the production of this so  
called software. 

Message No. 15
Date: Monday, 14 February 2000
Time: 1:11 A.M.

Subject: Re: Discussion No. 2 (Application of Chemical Kinetics)
From: Georg Ercilla

Hi there people!  It's me...Georgina Ercilla of EN1C.
 
Chemical kinetics is the study of the rates of chemical reactions and 
the factors that control both the yields of product molecules and the 
consumption of the reacting species. 

Chemical kinetics can be applied in chemical industry.  It can be a 
big use in manufacturing medicines, fertilizers, explosives, and 
more... 

For instance, in producing fertilizers, one must know how effective it
is on plants.  There is a need to study how fast it can react to the 
soil and plants and how long it can last.  For medicines, certain 
dosage is needed for every person for more effective results.  
And with this, chemical kinetics is very important to make the dosage 
because there are chemicals contained by certain medicines that may be
not good for some. 

Another application of chemical kinetics is on the chemical reaction 
involved in the process.  This can be applied in measuring the speed 
at which a reaction proceeds to form products.  Another is in 
unimolecular process, in which a single chemical component decomposes 
into products.  The kinetic expression for this is:

             rate = k(reactant).  

With the process of heating, this can be achieved.  and certainly, 
the rate of reaction are affected by temperature, concentrations of 
solutions, catalyst, and the surface area.  Raising the temperature 
and the energies of reactants is one method for accelerating the 
rate of reaction.

Message No. 16
Date: Monday, 14 February 2000
Time: 8:56 P.M.

Subject: Re: Discussion No. 2 (Application of Chemical Kinetics)
From: Kristine Marie Franco Malijan

Hi! I'm Kristine M. of EN1J.

Chemical kinetics is defined as the "study of reaction  rates and 
their relation to the mechanism of a reaction in a fascinating area 
of C H E M I S T R Y." 

Therefore, I conclude that chemical kinetics is very important in 
chemical processes especially in industries on glass making, ceramics,
metallurgy, sugar refining and soap boiling.
 
Chemical kinetics is also applied in synthetic dyes and drugs.
It also eliminates certain natural ones in the market. It also used
in explosives such as gun powder. 

Good day!

Message No. 17
Date: Monday, 14 February 2000
Time: 9:51 P.M.

Subject: Re: Discussion No. 2 (Application of Chemical Kinetics)
From: Wendell Deocampo

Hi. I'm Wendell.

"In the reactions involving substances in the gaseous state or in 
solution, rections occur at the boundary, or interface, between two 
phases. The rate of the reaction between two phases depends to a 
great extent on the area of surface contact between them . 

Reactions involving solids occur on their surfaces. Finely divided 
solids, because of the greater surface area available, react more 
rapidly than do large pieces of the same substances. For example 
large pieces of wood smolder slowly, smaller pieces burn rapidly 
and grain dust may burn at an explosive rate!"

Message No. 18
Date: Wednesday, 16 February 2000
Time: 1:52 A.M.

Subject: Re: Discussion No. 1 (Application of Chemical Kinetics)
From: Mark Lobo

Greetings everyone. My name is Mark Lobo of EN1J.

"Chemical kenetics is the study of chemical reactions, rate laws 
 and reaction mechanism."

INDUSTRIAL GASES

ACETYLENE is employed with oxygen to give a high welding temperature 
and in the manufacture of industrial chemicals such as vinyl chloride,
acrynonitrile and acetic acid.

CARBON DIOXIDE. By far ,the largest use of the solid form is for 
refrigerating and freezing  ice cream, meat and other foods.

An added advantage  is that a CO2 atmosphere reduces meat and food 
spoilage bacteria.

A catalytic converter used to decrease pollutants in the exhaust of 
the automobile.

In burning of rocket fuel we seek a rapid release of gaseous products 
and energy  to give the rocket a maximum thrust.

In MILITARY EXPLOSIVES, ammonium nitrite is used as a major explosive 
substance.

Message No. 19
Date: Wednesday, 16 February 2000
Time: 8:02 P.M.

Subject: Re: Discussion No. 2 (Application of Chemical Kinetics)
From: Dannmar Jan Dumdum Plazo


Hello everyone. My name is Dannmar Jan Plazo of EN1J.

NUCLEAR INDUSTRIES 
  
"... involving solution of fuel elements as nitrates and separation 
using the tributyl phosphate solvent, this process is called   
purix process, or using methyl isolutyl ketone (hexone) is called 
the absolute redox process. "

Message No. 20
Date: Wednesday, 16 February 2000
Time: 10:21 P.M.

Subject: Re: Discussion No. 2 (Application of Chemical Kinetics)
From: Kenneth Lanosia Alarcon

I am Kenneth Alarcon of EN1C.

The application of chemical kinetics in chemical industry - in the 
structure of chemical industry, the gaseous hydrocarbon ethylene and 
its many reaction illustrates both the complexity of the chemical 
industry and its close ties with petroleum refining.  

Ethylene is the product of the breakdown or "cracking" of larger 
hydrocarbon molecules during petroleum refining.  It is also produced 
in special furnaces in modern chemical plants.  Ethylene is used 
directly as a fuel for welding, as a refrigerant, and as an accelerator
for plant growth and fruit ripening.  The main portion of the ethylene
produced however is transformed chemically to other substances.  
The reaction with water can take place in two stages:

(1)  2 C2H4 + H2O  = C2H5OC2H5  (ether) 
(2)  C2H5OC2H5 + H2O  = 2 C2H5OH  (ethanol) 

Depending on the amount of water that reacts with the ethylene, either
ether or ethylene alcohol can be formed.  As the reaction is carried 
out industrially, both are produced and thus the the line on the 
diagram splits into two lines.  

This illustrates yet another feature of the chemical industry.  
The frequent formation of "coproducts" (two or more products from one 
operation, both of which have commercial value.  In some case the 
chemistry of the reaction is such that the coproducts are formed in 
fixed proportion that cannot be changed. 

The application of chemical kinetics in chemical reaction - the rate 
at which a chemical process give product is called rate of reaction.  
Rates of reaction, like all rates, involve a division by some unit of 
time.  For example, the rate of production of a well in tons per hour.

"The rate of a chemical reaction is measured by the decrease in 
concentration of a reactant or the increase in concentration of a 
product during a given unit of time".  

For example, pure hydrogen peroxide, dissolved in water, slowly 
decomposes according to the following equation:

2 H2O2 = 2 H2O + O2 

The change in concentration with the time of 40 degrees of a solution 
of that is initially in hydrogen peroxide. Chemical kinetics can be 
applied  in the following:  through the experimental measurement of 
reaction rates - at measured time interval samples maybe removed 
in a thermostated reaction vessel.  The reaction slowed down or 
stopped by rapid chilling and the sample analyzed by titration or 
other analytical method. Sometimes several identical samples of 
reacting material are started at the same time and each is chilled 
quickly at different time intervals.