Message No. 41
Date: Wednesday, 23 February 2000
Time: 1:50 A.M.

Subject: Discussion No. 2 (Application of Chemical Kinetics)
From: Gladys May Disen

Hi! I'm Gladys May of EN1J.

Chemical Kinetics is the rate of the reaction. 

In petroleum refining, chemical kinetics is used during the process 
of breaking down the crude oil into its petroleum by-products example 
is Petron refinery Limay Bataan. 

Rare metal production uses chemical kinetics during the extracting 
from raw metal such as molybdenum in Pacific Rare Metal Rosario, Cavite
where they use natural resources from Austria.
                  
Petrochemical uses chemical kinetics during the process of producing 
by-products such as vinyl, like for example in
Philippine Petrochemical Products Inc. in Rosario, Cavite.            

In petroleum process, a mixture of thousands of organic substances, 
has proved adaptable to our changing needs. It has been adapted, 
through changing patterns of processing or refining, to the 
manufacture of a variety of fuels and through chemical changes to the 
manufacture of a host of pure chemical substances, the petrochemicals. 

Message No. 42
Date: Wednesday, 23 February 2000
Time: 2:31 A.M.

Subject: Discussion No. 2 (Application of Chemical Kinetics)
From: Mary Grace Galvan

Hi. I'm Mary Grace Galvan of EN1J.

The metallocene or single-site catalysts that produces the power
to design presise polymers a feat that has briefly distracted them 
from the cost-cutting price battles typical of a comodity market.

Single-site catalyst differs from conventional olefin polymerization 
catalyst in that the metal atom usually is in constrained environment,
which allows single access by monomers to this catalytically active
site. Polymers grow by a single mechanism thus forming a more uniform
and reproducible polymer structure.

By determining the route and kinetics of the chain, a polymer can be 
designed for a particular performance target. For polyolefins, this 
technology translates to various performance enhancements including 
increased strength and toughness, better clarity and glass and 
easier and more consistent handling charaterestic.

Single-site catalysts are particularly useful for LLDPE
(linear low density polyethylene) production which copolymerizes 
ethylene with various -olefin comonomers, because the comonomers are 
incorporated more uniformly that they are with conventional catalysts.
 
The resultant polymers have a narrow molecular  weight distance 
predictable physical and mechanical properties. Such control over the
polymers structure can be very powerful, allowing for targeted 
performances properties from barrier resistance to tack (stickiness) 
to melting point, but the area has not yet been fully explored.

Message No. 43
Date: Thursday, 24 February 2000
Time: 2:34 A.M.

Subject: Discussion No. 2 (Application of Chemical Kinetics)
From: Marianne Caro

Hello friends. I'm Marianne of EN1C.

Chlorofluorocarbons(CFCs) are ideal compounds for refrigeration and 
air conditioning applications because they are nontoxic and 
chemically inert.

However, the unreactivity of the compounds causes them to persist 
for long periods in the atmosphere. Eventually, these molecules 
reach altitudes where ultraviolet light causes them to decompose 
producing chlorine atoms that catalyze the decomposition of the
ozone in the stratosphere.  

The search for substitutes for CFCs is now well underway. 
One strategy for replacing CFCs has been switch to similar compounds
that contain carbon and hydrogen atom. For example, the U.S. appliance
industry has switched from freon-12(CF2Cl) to the compound 
CH2FCH3(called HFC-134a) for home refrigerators, and most of the new
cars and trucks sold in the U.S. have air conditioners that use 
HFC-134a. 

The electronic industry which formerly used large quantites of CFCs 
as precision cleaning agent, has also switched to other chemicals.
For example, IBM's San Jose manufacturing facility, which was the 
largest emitter of CFCs, has now switch completely to water-based 
cleaning technologies.

Ozone is a powerful oxidizing agent that can react with other air 
pollutants to form substances irritating to the eyes and lungs. 
In the series of reactions nitric oxide is acting as a true catalyst
because it assists the production of ozone without being consumed 
itself. This can be seen by summing the reactions: 

         NO(g) + 1/2 O2(g) --> NO2(g)
            NO2(g) + O2(g) --> NO(g) + O3(g)           
          ---------------------------------
                   3/2 O2(g) --> O3(g)

In the atmosphere the presence of nitric oxide has opposite effect-
the depletion of ozone. The series of reactions involved is:

       NO(g) + O3(g) -->  NO2(g) + O2(g)
        O(g) + NO2(g) --> NO(g) + O2(g)
     -----------------------------------
        O(g) + O3(g) -->  2O2(g)
     
Nitric oxide is again catalytic but here its effect is to change O3 
to O2. This is a potential because O3, which absorbs ultraviolet light,
is necessary to protect us from the harmful effects to this 
high-energy radiation. 

Over the last decade research has shown that the ozone layer in the 
upper atmosphere is also threatened by freons. The most commonly used 
substance of this type was freon-12, CCl2F2.  The chemical inertness 
of freons makes them more useful but also creates a problem. 
Eventually, they migrate into the upper atmosphere to be decomposed 
by high-energy light. Among the decomposition products are chlorine 
atoms. These chlorine atoms can catalyze the decomposition of
ozone.      

Message No. 44
Date: Saturday, 26 February 2000
Time: 10:47 P.M.

Subject: Discussion No. 2 (Application of Chemical Kinetics)
From: Margielyn Cortez

Hi. I'm Margielyn Cortez of EN1C. 

Exothermic reactions usually favor formation products.
Unfortunately, this criterion is insufficient in a sense:
a reaction may be product-favored but still require such a long 
time to occur that it would take several human lifetimes to 
produce appreciable quantities of products.

Such a reaction is of little use if you are trying to make and 
sell a products. This problem is the concern of chemical kinetics.

One of the factor that affect the speed of reaction is catalsyts.
This is a substance that accelarate chemical reactions but are not 
themselves transformed.

Catalyst are metal-based and often contain precious metals, such as 
platinum and palladium. In the United States more than $600 M worth 
of such catalyst are employed annually by the chemical-processing 
industry, almost half of them in the preparation of polymers such as
polyethylene. 

About 7 billion kgs of nitric acid is made annually in the U.S. 
using the Ostwald process, the first step of which involves the  
controlled oxidation of ammonia over a Pt-containing catalyst.

The platinum-rhodium gaze catalyst used for the oxidation of ammonia 
in the manufacture of nitric acid

                Pt-containing catalyst
4NH3(g) + 5O2(g)---------------------->4NO(g)+6H2O(g) Hrxn= -905.5kJ

Followed by further oxidation of NO to NO2

     
    2NO(g) + O2(g) -------> 2NO2(g)  Hrxn = -114.1kJ

In the typical plant, a mixture of air with 10% NH3 is passed very 
rapidly over the catalyst at high pressure and at about 850 degree
celsius. Roughly 96% of the ammonia is converted to NO2, making this 
one of the most efficient industrial catalytic reactions. The final 
step is to absorb the NO2 into water to give the acid and NO, the 
process:

    3NO3(g) +H2O(l)----> 2HNO3(aq) + NO(g) Hrxn = -138.2kJ   

Message No. 45
Date: Sunday, 5 March 2000
Time: 7:57 P.M.

Subject: Discussion No. 2 (Application of Chemical Kinetics)
From: Julie Ann Alegarbes

Hello everyone! My name is Julie Ann V. Alegarbes of EN1C.

Perhaps the most significant aspect of modern chemistry was the 
proliferation of the research school in the 19th century, and its 
adaptation to large scale industrial enterprises in the 20th century. 

Pharmaceutical and and petrochemical industries followed suit, and 
are among those employing most of the trained chemists. Perhaps most 
impressive, in the field of of pharmacy, was the discovery and 
synthesis penicillin-one of a class of substances, produced by 
microorganisms, that destroy or inhibit the growth of other 
microorganisms. The fabricatuion of long chained carbon molecules
(polymers) also became a central concern od industry. The work of 
Herman Staudigerin the chemistry of macromolecules and the synthesis 
of Julius A. Nieuwland of neoprene (basis of synthetic rubber) was 
the starting point for many industrial products. Gradually, chemists 
came to realize the potential usefulness of chemicals previously 
considered waste. 

Message No. 46
Date: Sunday, 5 March 2000
Time: 11:28 P.M.
      
Subject: Discussion No. 2 (Application of Chemical Kinetics)
From: Fritz Seares

Hi. I'm Fritz Francois Aguero Seares of EN1C.

My discussion shows the chemical properties of sulfuric acid and its 
types of reactions. 

Sulfuric acid plants in the U.S. produces 14% of sulfuric acid a year.
This shows that sulfuric ranks as the single most significant 
industrial chemical. Per capita use of sulfuric acid has been taken 
as one index of the technical development of a nation. Perhaps 
surprisingly, sulfuric acid and the sulfate ion rarely appear in 
finished materials. 

Sulfuric acid is used extensively as an acid because it is the cheapest
strong acid. It used to manufacture fertilizers, leather, tin plate, 
and other chemicals, to purify petroleum, and to make dye fabrics.

Sulfuric acid is prepared from elemental sulfur or sulfides. Sulfur is 
burned in air, and the nonmetal sulfur is oxidized by the more 
electronegative nonmetal oxygen. Covalent molecules of gaseous
sulfur dioxide, with sulfur having one of its common oxidation numbers
(+4), result.

        	S8 + 8 O2 -->  8 SO2

The sulfur is then oxidized to its highest oxidation number (+6) by 
oxygen giving sulfur trioxide in a reversible reaction.

			2 SO2 + O2 --> 
                                   <--   2 SO3

Even though the yield from this reaction is highest at lower 
temperatures, sulfur trioxide forms slowly at this temperatures. 
At higher temperatures, it forms more rapidly, but the yield is lower.
In order to get as high yield as possible, the reaction is run at 
lower temperatures with vanadium oxide, V2O5, as a catalyst. 

A catalyst is a substance that changes the speed of a certain chemical 
reaction without affecting the yield and without undergoing a 
permanent chemical change itself.

Since sulfur trioxide is an oxide nonmetal in which the nonmetal has 
a high oxidation number, we expect it to react with water to form an 
acid- in this case sulfuric acid.

		H2O + SO3 -->  H2SO4

Sulfuric acid is an oxidizing agent, but it is not often used 
industrially as one. In fact its oxidizing ability prevents it from 
being used in two potentially useful reactions: the preparation of 
hydrogen bromide and of hydrogen iodide by reaction with the respective
metal halides. But sulfuric acid is recognized as one of the useful 
ingredient in chmical industries as it can be used as a main source 
for hydrogen ions.

Thank you and good day.

Message No. 47
Date: Sunday, 5 March 2000
Time: 11:36 P.M.

Subject: Discussion No. 2 (Application of Chemical Kinetics)
From: Arthur Ardosa

Hello all. I'm Arthur Ardosa  of EN1C.

Hydrogenation or hardening, as applied , to fats and oils , may be 
defined as the conversion of various unsaturated  radicals of fatty 
glycerides into more highly or copmpletely saturate glcerides by 
the addition of hydrogen in the presence  of a catalyst.  

Various fats and oils such as soybean, cottonseed, fish, whale and 
peanut, are converted  by partial hydrogenation into fats of a 
composition more suitable for shortening, margarine and other edible 
purposes, as well as for soap making and numerous other industrial 
uses.  

The object of hydrogenation is not only to raise the melting point 
but to greatly improve the keeping qualities, taste and odor for many 
oils.  It is frequently accompanied by isomerization with a 
significant increase in melting point, caused for example by oleic 
isomerizing to a elaidic acid.  As the reaction itself is exothermic, 
the chief energy requirement are in the production of hydrogen warming 
of the oil, pumping, and filtering.  The reaction maybe generalized: 

           (C17H31COO)3C3H5 + 3H2 ---->  (C17H33COO) 3C3H5
                             deltaH = -420.8 KJ/KG

Chemical kinetics is used because hydrogen is added in the catalyst. 
Thus, speeding up hydrogenation.

Message No. 48
Date: Monday, 6 March 2000
Time: 2:20 A.M.

Subject: Discussion No. 2 (Application of Chemical Kinetics)
From: Mark E. Santiago

Hi everyone. I'm Mark Santiago.
 
Every chemical reaction takes place at a definite rate depending on 
the conditions under which it occurs. These conditions are the 
concentration (or for gases, the pressures) of the reacting 
substances, temperature, the presence of the catalylic agent, and 
radiation (for example light of a suitable wavelength).  

Some reactions ar so rapid that they appear to be instantaneous -- 
for example the neutralization of an acid by a base while others 
are so slow at ordinary temperature that no detectable change would 
be noticed in many years-- for example combination of oygen and 
hydrogen to form water, in the absence of a catalyst. 

Message No. 49
Date: Monday, 6 March 2000
Time: 2:47 A.M.

Subject: Discussion No. 2 (Application of Chemical Kinetics)
From: Jose Celis Ycogo

Hi. My name is Jose Ycogo of EN1C.

LIQUID CRYSTALS 
The display of letters and numbers on digital watches, is due to 
liquid crystals. These crystals, when subjected to extreme temperature,
change their properties. This change has been found successful for 
many industrial applications. 

Liquid crystals are substances that have the properties of solids 
and liquids. We know that liquids are substances with no definite 
shape, are fluid and take the shape of their containers. On the other 
hand ,crystals are solid that have a definite shape and do not follow 
the shape of their container because of their rigid structure. 
Their atoms are arrange in a fixed pattern. Even at high temperatures 
crystals do not change their atomic shape and characteristics. 

Liquid crystals also have ordered atoms, however, their pattern is not
rigid but flexible. Thus light or heat can penetrate them and cause 
the atoms to move in one direction or another. At very high temperature
the molecules become partially ordered. At this point, the liquid 
crystals is a cloudy or translucent fluid that has some properties of 
solid crystals. The molecular structure of a liquid crystal can be 
changed easily by stress, electric and magnetic fields, pressure and 
temperature. All liquid crystals scatter light that shines on them. 
These properties make them perfect in many industrial applications. 

Message No. 50
Date: Tuesday, 7 March 2000
Time: 1:37 A.M.

Subject: Discussion No. 2 (Application of Chemical Kinetics)
From: Verna May Cabarrubias

Hi! I'm Verna May Cabarrubias of EN1J.

One of the chemical industry that make use the chemical kinetics 
principle is DOW Plastics. DOW has designed physical properties into 
the resins to position them between conventional linear low density 
polyethylene(LLPDE) on the low end and polyolefin elastomers on the 
high end. 

For example the new risens have dart impact strength (resistance to 
puncture 2 to 4 times that of LLPDE at comparable modulus, measure 
of stiffness). That combination means producers can make film at 
lesser thickness for economy of resin used or compound the resins 
with higher levels of recycled resins in other resins type increases 
its modulus usually sacrifice dart impact strength and enhance 
stiffness means the new resins may replaced paper in the industrial 
bagging. Impact strength is 2 or 4 times that of high density 
polyethylene at comparable melt viscosities that combines strength 
and ease of  processibility. 

The result of adequate shape holding plus package and seal times but 
that the new resins will be priced at a 3-6 % per lb. premium LLPDE, 
commensurate with the added value. The enchanced properties of elite 
polythylenes come from the company's in-site constrained geometry 
catalyst. Other metallocene catalysts have 2 cyclopentadienyl anions 
that float spinning over the coordination sphere of a metal such as 
ZIKCONIUM(IV). Inspite catalysts have a silicon tonded to one of the 
carbons of a cyclopentadienyl ring coordinated to titanium. 

This silicon nitrogen"short leash" pulling on the cyclopenladienyl 
ring opens up the bon angle between cyclopentadienyl and other 
ligands.