Általános Kémiához ábrák, etc.
2009. ősz
ÁLTALÁNOS KÉMIA
I. éves Kémia BSc évf.
(Fizkém-en adott bemutatóból)
Cél, feladat:
A kémiai fogalomrendszer, gondolkodásmód bemutatása, s
ezzel a tételes tárgyak előkészítése.
Alapfogalmak: rendszeresen, precízen
Bonyolultabb fogalmak: halljanak róla, szokjanak a
gondolathoz, még akkor is, ha nem ért(het)ik pontosan.
Tartalom:
I. Alapfogalmak (A)
II. Az anyag atomi - molekuláris szerkezete. (B)
III. Az anyag makroszkopikus megjelenése.
IV. Elektrokémia (A)
V. Reakciókinetika (A)
VI. A kémiai kötés kvantummechanikai leírása (B)
Vizsga:
írásbeli (belépő) + szóbeli (egy A, egy B tétel)
A kémia felosztása különböző lehet
Egy könyvkiadó: WileyEurope > Chemistry
Browse Chemistry subjects
Analytical Chemistry
Industrial Chemistry
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Inorganic Chemistry
Chemical Engineering
Organic Chemistry
Computational Chemistry
& Molecular Modeling
Physical Chemistry
Polymer Science & Technology
Electrochemistry
Special Topics
Environmental Chemistry
Spectroscopy
General Chemistry
A kémia felosztása különböző lehet
WileyEurope > Chemistry
Analytical Chemistry
Biochemistry
Chemical Engineering
Computational Chemistry & Molecular Modeling
Electrochemistry
Environmental Chemistry
General Chemistry
Industrial Chemistry
Inorganic Chemistry
Organic Chemistry
Physical Chemistry
Polymer Science & Technology
Special Topics
Spectroscopy
ACS Divisions
Agricultural & Food Chemistry
Agrochemicals
Analytical Chemistry
Biochemical Technology
Biological Chemistry
Carbohydrate Chemistry
Cellulose, Paper & Textile
Chemical Toxicology
Colloid & Surface Chemistry
Computers in Chemistry
Environmental Chemistry
Fluorine Chemistry
Fuel Chemistry
Geochemistry
Industrial & EngineeringChemistry
Inorganic Chemistry
Medicinal Chemistry
Nuclear Chemistry &Technology
Organic Chemistry
Petroleum Chemistry
Physical Chemistry
Polymer Chemistry
Polymeric Materials: Rubber
Kémia mindenhol
TOP 50 CHEMICALS:
Rank
1995
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1994
1
2
3
4
5
6
7
8
10
9
11
18
14
12
13
16
Billions of lb
1995
1994
Sulfuric acid
95.36 89.63
Nitrogen
68.04 63.91
Oxygen
53.48 50.08
Ethylene
46.97 44.60
Lime(b)
41.23 38.37
Ammonia
35.60 34.51
Phosphoric acid
26.19 25.58
Sodium hydroxide
26.19 25.11
Propylene
25.69 23.94
Chlorine
25.09 24.37
Sodium carbonate(c)
22.28 20.56
Methyl tert-butyl ether 17.62 13.61
Ethylene dichloride
17.26 16.76
Nitric acid
17.24 17.22
Ammonium nitrate(d)
15.99 17.03
Benzene
15.97 15.27
22
20
Carbon dioxide(f)
10.89
11.80
27
26
Hydrochloric acid
7.33
7.47
33
33
Acetic acid
4.68
3.98
42
43
42
43
Titanium dioxide
Acetone
2.77
2.76
2.76
2.66
50
49
Bisphenol A
1.62
1.70
Top 50 Chemical Companies in 1999
Rank
Rank
1999 1998
Company
Total sales
Company
Chemical sales
Chemical operating profits
Total sales
1999 ($ M)
Chemical sales
1999 ($ M) % of
total
Chem. Oper. profits
1999 ($ M) %
1
2
3
4
5
6
7
8
9
10
11
12
13
1
2
3
4
8
6
5
19
35
11
28
10
13
BASF (Germany)
DuPont (U.S.)
Bayer (Germany)
Dow Chemical (U.S.)
Exxon Mobil (U.S.)b
ICI (U.K.)
Shell (U.K./Netherlands)
Akzo Nobel (Netherlands)
Degussa-Hüls (Germany)c
BP Amoco (U.K.)
Total (France)c 42,069.0
Elf Aquitaine (France)
Sumimoto Chemical (Japan)
34,689.4
29,740.0
29,106.7
18,929.0
185,527.0
13,671.5
149,706.0
15,375.9
13,157.7
101,180.0
9,343.6
37,872.8
8,342.9
31,250.3
27,688 .0
20,192.5
18,600.0
13,777.0
13,671.5
12,886.0
12,323.5
10,085.8
9,392.0
22.2
9,272.2
8,136.5
90.1%
93.1
69.4
98.3
7.4
100.0
8.6
80.1
76.7
9.3
643.5
24.5
97.5
1,350.9
2,961.0
3,024.7
2,732.0
1,354.0
923.9
885.0
819.3
544.6
1,100.0
6.9
540.2
588.9
4.3
10.7
15.0
14.7
9.8
6.8
6.9
6.6
5.4
11.7
16
18
Henkel (Germany)
12,104.0
7,324.6
60.5
604.1
8.2
Nemzeti jövedelmekhez hasonlítva:
Comparative economic indicators, 2000
Hungary Slovenia
GDP (US$ bn)
45.6
18.1
GDP per head (US$ at PPP) 9,035
14,250
Slovakia
19.2
8,718
5.8
7.2
March 12, 2002 : The survey, published in a recent issue of the Society's publication, Chemical
& Engineering News (C & EN), ranks the global top 50 by their chemical sales. It also charts
their total sales, chemical operating profits and capital spending
Kémia a háztartásban
http://consumerlawpage.com/article/household-chemicals.shtml
TOP "10" HAZARDOUS HOUSEHOLD CHEMICALSBy Richard Alexander
AIR FRESHENERS: Most air fresheners interfere with your ability to smell by coating your
nasal passages with an oil film, or by releasing a nerve deadening agent. Known toxic
chemicals found in an air freshener: Formaldehyde: Highly toxic, known carcinogen. Phenol:
When phenol touches your skin it can cause it to swell, burn, peel, and break out in hives. Can
cause cold sweats,convulsions, circulatory collapse, coma and even death.
AMMONIA: It is a very volatile chemical, it is very damaging to your eyes, respiratory tract
and skin.
BLEACH: It is a strong corrosive. It will irritate or burn the skin, eyes and respiratory tract. It
may cause pulmonary edema or vomiting and coma if ingested. WARNING: never mix bleach
with ammonia it may cause fumes which can be DEADLY. NH2Cl, klóramin keletkezhet
DISHWASHER DETERGENTS: Most products contain chlorine in a dry form that is highly
concentrated.# 1 cause of child poisonings, according to poison control centers.
DRAIN CLEANER: Most drain cleaners contain lye, hydrochloric acid or trichloroethane.
Lye: Caustic, burns skin and eyes, if ingested will damage esophagus and stomach.
Hydrochloric acid: Corrosive, eye and skin irritant, damages kidneys, liver and digestive tract.
Trichloroethane: Eye and skin irritant, nervous system depressant; damages liver and kidneys.
FURNITURE POLISH: Petroleum Distillates: Highly flammable, can cause skin and
lung cancer. Phenol: (see Air fresheners, Phenol.) Nitrobenzene: Easily absorbed through
the skin, extremely toxic.
MOLD AND MILDEW CLEANERS: Chemicals contained are: Sodium hypochlorite:
Corrosive, irritates or burns skin and eyes, causes fluid in the lungs which can lead to coma
or death. Formaldehyde: Highly toxic, known carcinogen. Irritant to eyes, nose, throat, and
skin. May cause nausea, headaches, nosebleeds, dizziness, memory loss and shortness of
breath.
OVEN CLEANER: Sodium Hydroxide (Lye): Caustic, strong irritant, burns to both skin
and eyes. Inhibits reflexes, will cause severe tissue damage if swallowed.
ANTIBACTERIAL CLEANERS: may contain: Triclosan: Absorption through the skin
can be tied to liver damage. (Ált. fertőtlenítőszer – kórházak :
LAUNDRY ROOM PRODUCTS: Sodium or calcium hypocrite!? nyilván hypochlorite:
Highly corrosive, irritates or burns skin, eyes or respiratory tract. Linear alkylate sulfonate:
Absorbed through the skin. Known liver damaging agent. Sodium Tripolyphosphate:
Irritates skin and mucous membranes, causes vomiting. Easily absorbed through the skin
TOILET BOWL CLEANERS: Hydrochloric acid: Highly corrosive, irritant to both skin
and eyes. Damages kidneys and liver. Hypochlorite Bleach: Corrosive, irritates or burns
eyes, skin and respiratory tract. May cause pulmonary edema, vomiting or coma if ingested.
Contact with other chemicals may cause chlorine fumes which may be fatal
Mi mindent tud a kémia?
VÁLOGATÁSOK KURRENS EREDMÉNYEKBŐL
Gyógyszerek, bioaktív anyagok
INHIBITORS TARGET KEY TB ENZYME
Iminosugars may provide leads for new class of tuberculosis drugs
2004
Scientists in England have designed and synthesized
the first inhibitors of an enzyme that is essential for
the survival of the tuberculosis bacterium [Org.
Biomol. Chem., 2, 2418 (2004)]. The compounds
might lead to better treatments for TB, which annually
infects 8 million to 10 million people and kills 2
million to 3 million. e and kills 2 million to 3 million.
September 21, 2009
Volume 87, Number 38, p. 8
New Tuberculosis Drug Target
The proteasome—the cell’s garbage disposal for
proteins—could become a target for new tuberculosis
drugs, biologists report. A team led by Carl Nathan of
Weill Cornell Medical College has found that some
oxathiazolone compounds kill tuberculosis-causing
bacteria by selectively inhibiting mycobacterial
proteasomes without affecting human proteasomes
(Nature, DOI: 10.1038/nature08357).
Fantázia a természetben és a laborban: molekuláris létrák
September 3, 2007
Volume 85, Number 36 , p. 7
When Organics Fail, Try Water
Ladder polyethers form readily from epoxides in water
Complex ladder polyether natural products, so named for their runglike structure, are the active
toxins found in the harmful algal blooms known as red tides. Red tides cause devastating
ecological damage, so scientists hope that by studying this water-promoted cascade reaction, they
will gain a better understanding of how and why these toxins form
Ezt is tudjuk ……
EPO
Understanding the function of endogenous
hormones and putting them to good use to
treat diseases has been one of the great
accomplishments of modern medicine. One
natural hormone that has turned out to be a
blockbuster drug--but not without some
controversy--is erythropoietin (EPO).
EPO is a glycoprotein (protein-sugar conjugate) that serves as the
primary regulator of red blood cells (erythrocytes) in mammals. It
stimulates bone marrow stem cells to differentiate into red blood cells
and controls hemoglobin synthesis and red blood cell concentration.
Human EPO is a 30,400-dalton molecule containing 165 amino acids
and four carbohydrate chains that incorporate sialic acid residues.
There are several forms of EPO, designated by Greek letters, that
differ only in the carbohydrate content.
In infants, EPO is produced mostly in the liver, but the kidneys become the primary site of EPO synthesis
shortly after birth. EPO production is stimulated by reduced oxygen content in arterial blood in the kidneys.
Circulating EPO binds to receptors on the surface of erythroid progenitor cells that in turn mature into red blood
cells.….. contnd
Human EPO was first isolated and later purified from urine in the
1970s. Interest in developing clinical uses for EPO led to the
discovery of the gene encoding EPO, and several groups devised
recombinant DNA methods to produce EPO by the mid-1980s.
Recombinant EPO quickly made it to market to treat anemia resulting
from a host of conditions, primarily kidney failure, HIV infection in
patients treated with AZT, and cancer chemotherapy. Doses of EPO
are given by injection one or more times per week to maintain a
normal hematocrit level, the ratio of red blood cell volume to total
blood volume. Generally, EPO might be prescribed for any condition
where blood oxygen levels are depressed and to help eliminate the
potential need for blood transfusions.
……
Enzyme immunoassays can provide a measure of serum EPO levels,
but the tests can't determine if the EPO is natural or produced
recombinantly and injected by unscrupulous athletes. The World
Anti-Doping Agency has now developed combination urine and blood
tests that can detect EPO abuse by athlets.
ROBBANTGATUNK?
Mercury Fulminate
Researchers finally determine X-ray structure of infamous explosive
the super-sensitive explosive with a nefarious 300-year
history, has been so difficult to handle in the lab that only
now have scientists finally determined its crystal structure.
Wolfgang Beck and Thomas M. Klapötke, professors at Ludwig Maximilians University in
Munich, Germany, and their colleagues report that, as expected, the molecule Hg(CNO)2 is
nearly linear, with the nitrogens carrying a positive charge and the oxygens a negative charge.
The mercury atom is bound to two carbon atoms, with the bonding arrangement O–N C– Hg–C
N–O (Z. Anorg. Allg. Chem. 2007, 633, 1417). This connectivity and linear structure was
predicted by a number of groups, including Beck's and Klapötke's. Other groups, however, had
predicted that the O atoms were bound to Hg.
Mercury fulminate is sensitive to friction, heat, and shock, and it decomposes violently
October 3, 2007
Also appeared in print Oct. 8, 2007, p. 11
Inorganic Chemistry
Mercury Tetrafluoride Synthesized
Elusive Hg(IV) species has been prepared in solid argon, neon
Jyllian Kemsley
Mercury, a group 12 element with a valence electron configuration of s 2d10, is
generally considered to be limited to the +1 and +2 oxidation states. Theoretical
work, however, has long predicted that mercury could be stable in the +4 oxidation
state. In a fundamental advance that opens new possibilities for mercury
compounds, that prediction has now been confirmed with the successful synthesis
of HgF4 using matrix isolation techniques (Angew. Chem., DOI:
10.1002/anie.200703710).
SCIENCE & TECHNOLOGY
RDX LINKS RUSSIAN CRASHES
2004 Sept.
Powerful explosive found in the debris of two planes
that crashed
Traces of RDX, a common military explosive
that is also known as hexogen or cyclonite,
were found at the crash sites of two Russian
planes that went down within minutes of
each other on Aug. 24, Russian authorities
report. RDX was also used in a suicide
bombing at a Moscow metro station on Aug.
31, news reports say.
"RDX is a very powerful explosive," says
Jimmie C. Oxley, a professor of chemistry at
the University of Rhode Island. "A terrorist
wouldn't need to conceal very much." RDX
has an explosive power considerably greater
than that of TNT, is chemically stable, and is
more susceptible than TNT to shock
detonation.
2009 Sept.
January 12, 2009
Volume 87, Number 2
p. 38
High-Nitrogen Anion Exceeds The Power Of RDX
German chemists report the synthesis of a collection of explosive
azidotetrazolate (CN7–) salts
Rachel A. Petkewich
In the quest for environmentally friendlier and more powerful explosives , researchers at Ludwig
Maximilians University, in Munich, report the synthesis of a collection of azidotetrazolate (CN 7–) salts that take a step toward
both goals (J. Am. Chem. Soc., DOI: 10.1021/ja8077522). Thomas M. Klapötke and Jörg Stierstorfer synthesized the CN7– anion
by deprotonating 5-azido-1H-tetrazole. The new salts have the highest nitrogen content reported for tetrazolate compounds. For
example, the hydrazinium salt, N2H5CN7, is 88.1% nitrogen by mass. These nitrogen-rich molecules are considered "greener"
than traditional explosives because they generate fewer carbon-based by-products that can damage artillery gun barrels and the
environment. The researchers' calculations indicate that N2H5CN7 has the highest detonation pressure and velocity of the new
compounds—values that exceed those of the powerful explosive RDX. Although hydrogen bonds help render N 2H5CN7
thermally stable at room temperature, the compound is still too sensitive to impact and friction for field use. Klapötke says
adding a methyl group to the anion may reduce its sensitivity enough for it to be used safely.
Gyönyörűszép Molekulák
Koordinációs KOMPLEXEK
"Molekuláris giroszkóp"
Játék, vagy tudomány? Klatrátok (zárványvegyületek)
2003
One example, reported by Bryan W. Eichhorn's group at the University of Maryland, is the
[As@Ni12@As20]3– ion. This cluster consists of an As20 pentagonal dodecahedron that encapsulates a Ni12
icosahedron, which contains an arsenic atom at its center. The As20 cage is related to the smallest fullerene, C20
5, 2003
C&EN May
Source: C&EN/ April 14, 2003
ION RECOGNITION
System exploits weak interactions to attract anion to cation
in capsule
A new approach to anion recognition that uses electrostatic
and hydrogen-bonding interactions has been developed by
chemists at the University of Missouri, Columbia.
"For the first time, we have utilized a single molecule to
completely encapsulate an ion pair in polar media,"
chemistry professor Jerry L. Atwood tells C&EN. "We
envision that resins incorporating these capsules could be
used in anion sensing in environmental applications."
Atwood and postdoc Agnieszka Szumna embedded a
tetramethylammonium cation in the pocket of a
resorcin[4]arene molecule functionalized with bulky amide
substituents. The complex selectively binds to a chloride
anion in solvents such as methanol [Chem. Comm., 2003,
940].
A kémia veszélyes tevékenység .....
May 11, 2009 Volume 87, Number 19 | p. 7 |
SAFETY
Negligence Caused UCLA Death
State safety and health agency faults university for training lapses, unsafe practices
When the incident occurred, Sangji was drawing
approximately 20 mL of 1.7 mol/L tertbutyllithium in pentane into a 60-mL syringe
when the syringe plunger was either ejected or
pulled out of the syringe. An undetermined amount
of the liquid splashed onto her hands, arms, and
torso. The ensuing fire burned more than 40% of her
body. One of the postdoctoral researchers used his
lab coat to extinguish the flames and called for help.
Sangji died of her injuries
Az anyag atomi-molekuláris
szerkezete
A modern kémia kezdetei:
Robert Boyle (1627–1691) was born at Lismore Castle, Munster,
Ireland, the fourteenth child of the Earl of Cork. As a young man of
means, he was tutored at home and on the Continent. He spent the later
years of the English Civil Wars at Oxford, reading and experimenting
with his assistants and colleagues. This group was committed to the New
Philosophy, which valued observation and experiment at least as much
as logical thinking in formulating accurate scientific understanding. At
the time of the restoration of the British monarchy in 1660, Boyle played a
key role in founding the Royal Society to nurture this new view of science.
Although Boyle's chief scientific interest was chemistry, his first
published scientific work, New Experiments Physico-Mechanicall,
Touching the Spring of the Air and its Effects (1660), concerned the
physical nature of air, as displayed in a brilliant series of experiments in
which he used an air pump to create a vacuum. The second edition of
this work, published in 1662, delineated the quantitative relationship
that Boyle derived from experimental values, later known as "Boyle's
law": that the volume of a gas varies inversely with pressure.
Robert Boyle at the age of thirty-seven, with his air pump in the background.
François Diodati reengraved this image from an engraving by William Faithorne, Opera varia (1680)
Courtesy Edgar Fahs Smith Memorial Collection, Dept. of Special Collections, University of Pennsylvania Library.
Robert Boyle (25 January 1627 – 31 December 1691)
was a natural philosopher, chemist, physicist, inventor,
and gentleman scientist, also noted for his writings in
theology. He is best known for the formulation of
Boyle's law.[2] Although his research and personal
philosophy clearly has its roots in the alchemical
tradition, he is largely regarded today as the first
modern chemist, and therefore one of the founders of
modern chemistry. Among his works, The Sceptical
Chymist is seen as a cornerstone book in the field of
chemistry.
Boyle was an advocate of corpuscularism, a form of atomism
that was slowly displacing Aristotelian and Paracelsian views
of the world. Instead of defining physical reality and
analyzing change in terms of Aristotelian substance and form
and the classical four elements of earth, air, fire, and water—
or the three Paracelsian elements of salt, sulfur, and
mercury—corpuscularism discussed reality and change in
terms of particles and their motion. Boyle believed that
chemical experiments could demonstrate the truth of the
corpuscularian philosophy. In this context he defined the
term element in Sceptical Chymist (1661): " . . . certain
primitive and simple, or perfectly unmingled bodies; which
not being made of any other bodies, or of one another, are the
ingredients of which all those called perfectly mixt bodies are
immediately compounded, and into which they are ultimately
resolved."
Robert Boyle:
The Skeptical Chemist, 1661 (!)
"Én megpróbáltam a kémiát más szempontok szerint művelni,
nem úgy, ahogy az eddigi kémikusok tették, hanem ahogy egy
tudóshoz illik." ....
"Bár viselnék az emberek inkább a tudományok előrehaladását
szívükön, mint önző érdeküket, akkor könnyen belátnák, hogy
nagyobb szolgálatot tennének a világnak, ha minden erejüket
kísérletek végzésére és megfigyelések gyűjtésére fordítanák,
ahelyett hogy kísérleti alapozás nélküli elméleteket állítanának
fel. "
Priestley
Joseph Priestley (13 March 1733 (Old Style) – 6 February
1804) was an 18th-century English theologian, Dissenting
clergyman, natural philosopher, educator, and political
theorist who published over 150 works. He is usually
credited with the discovery of oxygen, having isolated it in
its gaseous state, although Carl Wilhelm Scheele and
Antoine Lavoisier also have a claim to the discovery.[2]
During his lifetime, Priestley's considerable scientific
reputation rested on his invention of soda water, his
writings on electricity, and his discovery of several "airs"
(gases), the most famous being what Priestley dubbed
"dephlogisticated air" (oxygen). However, Priestley's
determination to defend phlogiston theory and to reject
what would become the Chemical Revolution eventually
left him isolated within the scientific community.
Mikhail Lomonosov (1711-1765), a polymath and writer of Imperial Russia
Polymath : polihisztor.
Lomonosov, 1753:
“Today I made an experiment in hermetic glass vessels in order to determine whether the mass of metals
increases from the action of pure heat. The experiment demonstrated that the famous Robert Boyle was
deluded, for without access of air from outside, the mass of the burnt metal remains the same."
Lavoisier
The Burning lenses
Calcination of a piece of metal with the burning lenses
Joseph Louis Proust
(1754 – 1826)
Állandó súlyviszonyok törvénye
John Dalton
(1766 – 1844)
Többszörös súlyviszonyok törvénye
Joseph Louis Gay-Lussac’s law of combining volumes (1808) (when
two gases react, the volumes of the reactants and products—if gases—
are in whole number ratios) tended to support Dalton’s atomic theory.
Dalton did not in fact accept Gay-Lussac's work, but the Italian chemist
Amedeo Avogadro (1776–1856) saw it as the key to a better
understanding of molecular constituency.
Amedeo Avogadro.
In 1811 Avogadro hypothesized that equal volumes of gases at the same temperature and pressure contain equal
numbers of molecules. From this hypothesis it followed that relative molecular weights of any two gases are the
same as the ratio of the densities of the two gases under the same conditions of temperature and pressure. Avogadro
also astutely reasoned that simple gases were not formed of solitary atoms but were instead compound molecules of
two or more atoms. (Avogadro did not actually use the word atom; at the time the words atom and molecule were
used almost interchangeably. He talked about three kinds of "molecules," including an "elementary molecule"—what
we would call an atom.) Thus Avogadro was able to overcome the difficulty that Dalton and others had encountered
when Gay-Lussac reported that above 100oC the volume of water vapor was twice
the volume of the oxygen used to form it. According to Avogadro, the molecule of
oxygen had split into two atoms in the course of forming water vapor.
Curiously, Avogadro's hypothesis was neglected for half a century after it was first published. Many reasons for this
neglect have been cited, including some theoretical problems, such as Jöns Jakob Berzelius's "dualism," which
asserted that compounds are held together by the attraction of positive and negative electrical charges, making it
inconceivable that a molecule composed of two electrically similar atoms—as in oxygen—could exist. In addition,
Avogadro was not part of an active community of chemists: the Italy of his day was far from the centers of chemistry
in France, Germany, England, and Sweden, where Berzelius was based.
Avogadro was a native of Turin, where his father, Count Filippo Avogadro, was a lawyer and government leader in
the Piedmont (Italy was then still divided into independent countries). Avogadro succeeded to his father's title, earned
degrees in law, and began to practice as an ecclesiastical lawyer. After obtaining his formal degrees, he took private
lessons in mathematics and sciences, including chemistry. For much of his career as a chemist he held the chair of
physical chemistry at the University of Turin.
Avogadro EREDETI CIKKÉBŐL! : http://web.lemoyne.edu/~giunta/avogadro.html
A TELJES SZOVEGET FILE-BAN ELTETTEM: avogadro-original
Essay on a Manner of Determining the Relative Masses of the Elementary Molecules of Bodies, and the Proportions in
Which They Enter into These Compounds
Journal de Physique 73, 58-76 (1811) [Alembic Club Reprint No. 4] I.
M. Gay-Lussac has shown in an interesting Memoir (Mémoires de la Société d'Arcueil,
Tome II.) that gases always unite in a very simple proportion by volume, and that when the
result of the union is a gas, its volume also is very simply related to those of its components.
But
the quantitative proportions of substances in compounds seem only to depend on the relative number of molecules which combine,
and on the number of composite molecules which result. It must then be admitted that very simple relations also exist between the
volumes of gaseous substances and the numbers of simple or compound molecules which form them. Kiemeles FG: The
first
hypothesis to present itself in this connection, and apparently even the only admissible one, is
the supposition that the number of integral molecules in any gases is always the same for equal
volumes, or always proportional to the volumes. Indeed, if we were to suppose that the number of molecules
contained in a given volume were different for different gases, it would scarcely be possible to conceive that the law regulating the
distance of molecules could give in all cases relations as simple as those which the facts just detailed compel us to acknowledge
between the volume and the number of molecules. On the other hand, it is very well conceivable that the molecules of gases being
at such a distance that their mutual attraction cannot be exercised, their varying attraction for caloric may be limited to condensing
the atmosphere formed by this fluid having any greater extent in the one case than in the other, and, consequently, without the
distance between the molecules varying; or, in other words, without the number of molecules contained in a given volume being
different. Dalton, it is true, has proposed a hypothesis directly opposed to this, namely that the quantity of caloric is always the
same for the molecules of all bodies whatsoever in the gaseous state, and that the greater or less attraction for caloric only results in
producing a greater or less condensation of this quantity around the molecules, and thus varying the distance between the
molecules themselves. But in our present ignorance of the manner in which this attraction of the molecules for caloric is exerted,
there is nothing to decide us à priori in favour of the one of these hypotheses rather than the other; and we should rather be inclined
to adopt a neutral hypothesis, which would make the distance between the molecules and the quantities of caloric vary according to
unknown laws, were it not that the hypothesis we have just proposed is based on that simplicity of relation between the volumes of
gases on combination, which would appear to be otherwise inexplicable.