Upload
paul-schumann
View
335
Download
0
Tags:
Embed Size (px)
DESCRIPTION
A ChemHistory Lesson by Paul Price, Trinity Valley School, Texas. This was presented at the ACT2 luncheon on 11/7/09 as part of CAST 2009 in Galveston Texas.
Citation preview
What We Do Is Hard!
• Memorization vs. Understanding• Various Levels of Abstraction• Critical Thinking• Putting it all together
The Use of History
• Puts Discoveries in Context– When?– Why Then?– How?
• The Human Element– I can do this
• Aligns with “Classic” Chem course – 2010 TEKS
The Organizing Principle
• When?
• Who?
• Why Then?
QuickTime™ and a decompressor
are needed to see this picture.
--->
--->
1913
1813
1803
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
--->
Dalton!?
• The mass of atoms?– Needs
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
Joseph Black (1728 - 1799)
• Analytical Balance
• Specific + Latent Heat
• Fixed Air (1754)– CaO + CO2 --> CaCO3
– Ca(OH)2 + CO2 --> CaCO3 + H2O
– MgCO3 + HCl --> H2O + CO2 + MgCl2
QuickTime™ and a decompressor
are needed to see this picture.
Pneumatic Chemistry
• H2 (1766) by Cavendish• O2, HCl, NH3, NO, N2O, SO2 by
Priestley (1774 - 86?)• Cl2 and O2 by Scheele (17??)• Lavoisier (O2 ?)
– Conservation of Mass
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
Proust and Dalton
CO
CO2
??
??
??
Nuts and Bolts
Cup 10 is BN. Can you figure out the rest?
Can you explain the data?
• All Matter is made up of indivisible particles called atoms.
• All atoms of the same element are exactly the same; atoms of different elements are different in some fundamental way
• Compounds form when atoms of different elements combine in unique fixed ratio
• In a chemical reaction, atoms are simply rearranged to create new compounds from old
Sample Homework
The Real Payoff
• CO
• One O weighs 1.33 times more!
• Define C = 1, O = 1.33
• Define C = 100 , O =
• Define C = 12, then O = 16133
A Small ProblemCompound Grams of
HydrogenGrams of Oxygen
Possible Formula
?
A 2.000 15.84
B 103.00 815.84
Rule of Greatest Simplicity
OH !
Dalton Mass Table
H = 1
O = 7.92
Gay-Lussac
• 2 vol H + 1 vol O = 2 vol water
• 3 vol H + 1 vol N = 2 vol ammonia
• 1 vol N + 1 vol O = 2 vol nitric oxide
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
Diatomics!
Future Developments
• Electrochemistry and diatomic bonding
• Why only H2? (not Hn)
• Organic Chemistry and Empirical vs. Molecular Formula
• Excellent Atomic Weights (Cannizzaro)
Periodic Table
• 6.02 x 1023
References• Arnold B. Arons; Development of Concepts of
Physics• Aaron J. Ihde; The Development of Modern
Chemistry• Classic Chemistry;
http://web.lemoyne.edu/~giunta/• Classic Papers from the History of Chemistry;
http://www.chemteam.info/Chem-History/Classic-Papers-Menu.html
Thank you Dennis
QuickTime™ and a decompressor
are needed to see this picture.