Moles

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Moles
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Is this a chemistry mole?
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Is this a chemistry mole?
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OK What the heck is it?
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Chemistry Mole

• The SI unit used to count tiny things called
  atoms or molecules or formula units or ions or
  anything else that comes in large quantities!

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Count the following

• a dozen donuts
• a pair of shoes
• a gross of pencils

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A mole is used to count in the same way that a
dozen, pair, or gross is.
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So. . .

• A mole is the SI unit used to measure the amount
  of a substance.
• It is used to count atoms, molecules, formula
  units, ions, or anything else!
• abbreviation mol

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• Avogadro came up with the mole.
• AKA Avogadros number
• 1 mole 6.02 x 1023 atoms, ions, molecules, or
  anything!

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A mole of something is very, very BIG!

• a mole of apples 6.02 x 1023 apples
• Thats 602,000,000,000,000,000,000,000 apples!

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How many . . .

• marbles are in one mole of marbles?
• ? 6.02 x 1023
• 1 mole 6.02 x 1023 of anything
• balloons are in one mole of balloons?
• ? 6.02 x 1023
• 1 mole 6.02 x 1023 of anything
• molecules are in one mole of C12H22O11?
• ? 6.02 x 1023
• 1 mole 6.02 x 1023 molecules sugar

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Molar Mass

• The molar mass is the mass (in grams) of one mole
  of a substance.
• molar mass of element (in g) 1 mole
• molar mass of compound (in g) 1 mole

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Finding Molar Mass of Elements

• To find the molar mass of an element, look at
  atomic mass on the periodic table.

6 C 12.0
atomic number
atomic mass

• Round atomic mass to one decimal place (tenth
  place).

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Examples

• Find the molar mass for
• 1 mole of carbon (C)
• 1 mole of lithium (Li)
• 1 mole of hydrogen (H2)
• H 2 x 1.0 g/mol
• 1 mole of oxygen (O2)
• O 2 x 16.0 g/mol

12.0 g/mol
6.9 g/mol
2.0 g/mol
32.0 g/mol
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Finding Molar Mass of Compounds

• Look up each elements atomic mass and round to 1
  decimal place.
• ADD the masses of EACH element together.
• Find the molar mass of one mole of KCl
• K 1 x 39.1 g/mol 39.1 g/mol
• Cl 1 x 35.5 g/mol 35.5 g/mol
• 74.6 g/mol

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Try these

• Find the molar mass of and write the mole/molar
  mass conversion for
• one mole of H2O
• one mole of C6H12O6

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Final Thought

• one mole 6.02 x 1023 things (atoms,
  molecules, formula units, ions)
• one mole molar mass (g/mol)
• So whats the relationship b/w moles, molar mass
  and molecules/formula units, atoms, ions?

6.02 x 1023 (particles)
1 mole
Molar mass _____________ _____________
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The End