1. Chemistry 125: Lecture 20 Rise of the Atomic Theory (1790-1805)
Elemental analysis was the technique for determining the composition of organic compounds. Lavoisier's early combustion and fermentation experiments showed a new, though naïve, attitude toward handling experimental data. Dalton’s atomic theory was consistent with the empirical laws of definite, equivalent, and multiple proportions. The basis of our current notation and of precise analysis was established by Berzelius, but confusion about atomic weight multiples, which could have been clarified at the outset by accepting the suggestions of Avogadro and Gay-Lussac, would persist for more than half a century.
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2. Elementary Treatise of Chemistry
1789
PRESENTED IN A NEW ORDER
AND ACCORDING TO MODERN DISCOVERIES
With Figures

3. Oxidation States 4° "oxygenated -ic" acid 1° "oxide" 2° "-ous" acid 3°
Radical

4. Elemental Analysis by Oil Combustion
Air
Supply
CO2
Collector
H2O
Collector
Oil
Supply
Lamp
Elemental Analysis by Oil Combustion

5. How to analyze a substance that will not burn cleanly?
Everyone knows how wine,
cider and mead are made…
How to analyze a substance that will not burn cleanly?
e.g.
grape sugar

6. Plate X: Fermentation Apparatus
CO2
Absorption by NaOH soln.
Foam catcher
any other Gas
H2O
Absorption
by CaCl2
Sugar/Yeast/Water
Plate X: Fermentation Apparatus

7. because of incomplete combustion (charring)
I can consider the materials subjected to fermentation and the products of fermen-tation as an algebraic equation; and by in turn supposing each of the elements of this equation to be unknown, I can derive a value and thus correct experiment by calculation and calculation by experi-ment. I have often profited from this way of correcting the preliminary results of my experiments.
Fermentation
Oxidation failed with
air
oxygen
sulfuric acid
mercuric oxide
etc.
because of incomplete combustion (charring)
it can furnish a means
of analyzing sugar

8. Lavoisier’s Bookkeeping
72 grains = 1 gros
8 gros = 1 ounce = g
Lavoisier’s Bookkeeping

9. Lavoisier’s Bookkeeping

10. Lavoisier’s Bookkeeping

11. ? Hydrogen Generator ……… + ! = Carbon + Water
157
313
103
9.4
from 28 gr. C
(modern theory)
144 cu. in. (100 grains) Carbonic Gas
380 cu. in. (13.7 grains) Flammable Gas
28 grains Carbon
1.38 g
………
Water
Red-hot Glass Tube
Hydrogen Generator
Water (less 85.7 grains)
Water pp ?
Carbon + Water
28 gr gr.
= Carbonic Gas + "Hydrogen"
100 gr gr. + = !
"I have thought it best to correct by calculation
and to present the experiment in all its simplicity."
Traité pp

12. Lavoisier Contributions
Clarity
Elements
Conservation
of Mass
Oxidation
Radical/Acid
Salts
Apparatus
Quantitation
Mass
volume
Substances
Reactions
Facts
Ideas
Words
Meaningful Names
Element - Oxidation State - Salt Composition
-ous, -ic, -ide, -ite, -ate

13. Lack of Imagination
[Chemistry's] present progress, however, is so rapid, and the facts, under the modern doctrine, have assumed so happy an arrangement, that we have ground to hope, even in our own times, to see it approach near to the highest state of perfec-tion of which it is susceptible.

14. Lavoisier Guillotined May 8, 1794 Age 50
"Il ne leur a fallu qu’un moment pour faire tomber cette tête, et cent années peut-être ne suffiront pas pour en reproduire une semblable."
"It took them only
an instant to make this head fall,
but a hundred years
may not suffice to reproduce one like it."
"The Republic has
no need of geniuses.”
But all of his equipment
(including 80 pounds of mercury) was seized for The People.
Seul un instant a師� n残essaire pour couper cette t腎e, et il faudra probablement plusdﾕun si縦le pour en faire une semblable
Le math士aticien Joseph Louis Lagrange dira le lendemain : " Il ne leur a fallu quﾕun moment pour faire tomber cette t腎e et cent ann仔s peut-腎re ne suffiront pas pour en reproduire une semblable.”
Rien qu'un instant pour couper cette t腎e, et en cent ans nous ne. trouverons pas une pareille
Seul un instant a師� n残essaire pour couper cette t腎e, et il faudra probablement plusdﾕun si縦le pour en faire une semblab
"Il ne faut qu'un instant pourtrancher cette t腎e et peut-腎re qu'un si縦le ne serapas suffisant pour en produire une autre ヹ'identique”
"Il ne leur a fallu", Joseph-Louis Lagrange remarked, "qu'un moment pour faire tomber cette t腎e, et cent ann仔s peut-腎re ne suffiront pas pour en reproduire une semblable."

15. Boyle Lavoisier √ √

16. John Dalton amateur meteorologist 1801
Why do gases of different density remain mixed rather than stratifying?
Continental European scientists proposed that different gases attract one another.

17. "the atoms of one kind did not repel the atoms of another kind"
“Heat Envelope”
Substitutes
homorepulsion
for
heteroattraction
Match 
Repulsion
Mismatch 
Reduced
Repulsion

18. Atoms Explain: Definite Proportions Equivalent Proportions Multiple Proportions
Pure compounds always have the same weight ratio of their elements.
If a parts of A react with b parts of B,
and a parts of A react with c parts of C,…
and d parts of D react with b parts of B,
then d parts of D react with c parts of C.
If two elements form several compounds,
their weight ratios are related by simple factors.

19. Claude Louis BERTHOLLET
Definite Proportions?
NON!
OUI !
metal alloys
natural "organic" materials 
"chemicals"
Claude Louis BERTHOLLET
( )
Joseph Louis PROUST
( )

20. Multiple Proportions
integral values consistent with simple atomic ratios
%err
of (O/C)
vs. modern -4 -5 -2
+11
of (O/N)
Oxides of Carbon %C %O 28 72 44 56
Carbonic Acid (1801)
Carbonous Acid (1789)
O/C
2.57
1.27
[1] ~2
2.19 ~4
4.12
2.02
Rel.
Oxides of Nitrogen %N %O
63.30
36.70
44.05
55.95
29.50
70.50
Nitrous Oxide (1810)
Nitrous Gas (1810)
Nitric Acid (1810)
O/N
0.58
1.27
2.39
for 1810 values

21. Genealogy Top

22. Berzelius etc. √

23. (double decomposition)
Jöns-Jakob
BERZELIUS
( )
Berzelius
Organic & Mineral
Analysis
2000 compounds in 6 years!
Good Atomic Weights
for 50 elements!
Teaching
& Writing
Textbook
(1808)
Electrolysis
Dualism
(double decomposition)
Notation for
Composition

24. Notation for Composition
Alchemy
Dalton
Berzelius

25. 1774 Symbols
Chemical
Symbols
of 1774
(Sweden)

26. Chemical Symbols of 1774 Berzelius Notation Dalton Notation (1808)
(1811)
H N C O P S Mg Ca
Na K Sr Ba Fe Zn Cu Pb
Ag Pt Au Hg
(Corresponding Berzelius Symbols)
Chemical
Symbols
of 1774
(Sweden)
HO HN NO HC OC
“When only one combination of two bodies can be obtained, it must be pre-sumed to be a binary one, unless some other cause appear to the contrary.”
N2O NO2 CO2 CH2
N2O NO2 CO2 CH2
NO3 SO SH3 C3H
“When two combinations are observed, they must be presumed to be a binary
and a ternary…
NO3 SO SH3 C3H
“When four…one binary, two ternary, and one quarternary, &c.
When three…a binary,
and the other two ternary. ”
Dalton’s Logic
Dalton Notation (1808)
Latin (international)
Analytical (NOT structural)

27. Benzoic should be H10C14O3 (“acid” as anhydride)
Abbreviations:
Dots denote O atoms
= KO CrO3
Didn’t catch on
Superscripts denote numbers of atoms
Benzoic should be H10C14O3 (“acid” as anhydride)

28. Atomic Weights and Equivalents

29. Dalton’s Atomic Weights (1808) Weights
% err 9 16 5 12 H C N O P S
2004 1 12 14 16 31 32
Dalton’s Atomic Weights (1808) Weights 1 5 7 9 13 /1 /2 /3 •

30. ? Silicon Chloride SiCl T. Thomson SiCl2 L. Gmelin
SiCl3 J. J. Berzelius
Chasing the Molecule p. 165
SiCl4 Wm. Odling

31. Joseph Louis Gay-Lussac (1809)
Oxidation of Sugar, etc. with NaClO3
Cleans up Lavoisier's Mass Balance
( )
,016 m
(record for 50 years)
volumes of hydrogen
per
volumes of oxygen
Water gives
Established that
atmosphere
composition
is invariant
with altitude.
   Volontaires, le 20 août 1804, Gay-Lussac et Biot réalisent l'ascension à partir du jardin du Conservatoire des Arts et Métiers.
 La nacelle ressemblait à l'arche de Noé. On y trouvait à la fois un cabinet de physique, où régnaient boussoles, baromètres, thermomètres, piles de Volta et hygromètres, et une ménagerie de petits animaux, pigeons, hirondelles, grenouilles, reptiles divers, abeilles et insectes variés. "
 Trop chargé le ballon ne parvint pas à dépasser mètres d'altirtude. Ils décidèrent de redescendre, Gay-Lussac se réservant de repartir seul. Mais un atterrissqage mouvementé abîma la nacelle et il dut y renoncer. Le 16 septembre, Gay-Lussac s'éleva du Conservatoire à 9h40. Parvenu à mètres il reprit des mesures relatives au magnétisme. A et mètres il prit des échantillons d'air. A 3h. 11', ne disposant plus que de 15 kilogrammes de lest il décida de descendre et se posa à Saint-Gourgons, à six lieues au nord-ouest de Rouen. Il avait atteint l'altitude record de mètres. Cet exploit, qui n'a pas été égalé pendant cinquante ans lui valut plus de renommée que les mesures effectuées, que les conditions rendirent, à son avais, pas assez fiables. Mais il en ressortit que le magnétisme terrestre ne variait pas sensiblement avec l'altitude et que la composition de l'air était inchangée.
- première loi : 1805
" Les quantités des corps entrant dans une combinaison chimique quelconque occupent, à l'état de vapeur ou de gaz, des volumes égaux ou multiples, toutes les conditions physiques étant identiques."
- deuxième loi 1808
" Le volume d'une combinaison, à l'état de vapeur ou de gaz, est toujours dans un rapport simple ou multiple avec le volume de chacun des composants ( et par conséquent avec la somme de volumes des éléments qui la composent). "
Service des Poudres
En 1824, avec Liebig, son assistant à Polytechnique, il étudia des détonateurs.
23,000 feet is more that half as high as commercial airliners fly.
volumes of hydrogen
per
1 volume of nitrogen
Ammonia gives
Alternative to Dalton's Law of Greatest Simplicity

32. End of Lecture 20 Oct. 22, 2008
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