1. 6/29/2011
Introduce moles
• Similar concept to dozen
• 12 vs
• 602 000 000 000 000 000 000 000
• 1 mole pennies
• Distribute evenly to everyone in world
• Each person could spend $1 000 000 every hour day
and night
• When die still have ½ of their pennies left
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2. 6/29/2011
Powers of 10
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3. 6/29/2011
The dozen and mass
• Buy potatoes by the ______
• Buy cantalopes by _______
• # lb/doz
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4. 6/29/2011
A Mole of Particles
Contains 6.02 x 1023 particles
1 mole C = 6.02 x 1023 C atoms
1 mole H2O = 6.02 x 1023 H2O molecules
1 mole NaCl = 6.02 x 1023 Na+ ions and
6.02 x 1023 Cl– ions
NaCl represents a “formula unit”
What about 1 mole of C6H12O6??
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5. 6/29/2011
Avogadro's Number
conversion factor!!!
6.02 x 1023 particles
1 mole
or
1 mole
6.02 x 1023 particles
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6. 6/29/2011
C as basis for mole mass
• 1 12C atom = 12 amu
• 1 mol 12C = 12 g
• Other atoms are related to C
• Atomic “weights” on PT
– Weighted averages of naturally occurring isotopes
– 1 mol naturally occurring C = 12.01 g
– Atomic mass C = 12.01 g/mol
• Due to differences in isotopic composition,
several elements have “range” of atomic weights
(2010)
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7. 6/29/2011
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