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The Mole Concept. What is a mole?. In 1811, a scientist named Amedeo Avogadro performed an experiment where he found that “ equal volumes of gases , at the same temperature and pressure, contain equal numbers of molecules .” http://www.bulldog.u-net.com/avogadro/avoga.html.
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What is a mole? • In 1811, a scientist named Amedeo Avogadro performed an experiment where he found that “equal volumes of gases, at the same temperature and pressure, contain equal numbers of molecules.” http://www.bulldog.u-net.com/avogadro/avoga.html
What is a mole? • Avogadro had no idea what the number of molecules was and he couldn’t measure them • BUT his hypothesis did lead to the eventual determination of this number, 6.02 x 1023 This became known as the measure of a MOLE.
What is a mole? • The mole became the reference point for most calculations and equations in chemistry • A mole is: 6.02 X 1023 particles Or: 602 000 000 000 000 000 000 000 particles!
How big is a mole? • You can have 6.02 x 1023 (or a mole) of anything! • For example: • A mole of standard soft drink cans would cover the surface of the earth to a depth of over 200 miles! http://www.bulldog.u-net.com/avogadro/avoga.html
What is a mole? • If you had mole of unpopped popcorn kernels, and spread them across the United States, the country would be covered in popcorn to a depth of over 9 miles! http://www.bulldog.u-net.com/avogadro/avoga.html
If the number is so big, how does it help us? • The mole helps measure atoms in a more manageable way because atoms are so small! • One mole of silver contains 6.02 x 1023 atoms of silver, but those atoms can fit into a small beaker!
Molar Mass • The atomic mass number under a symbol on the periodic table is also the molar mass of that element • The new units are: grams/mole. C 12.01 Molar Mass: 12.01 grams Mole
Molar Mass • For example: • A mole of sodium = 23.0 grams mole This means that if you could measure 6.02 x 1023atoms of sodium (or one mole) into a beaker, it would weigh 23.0 grams!
Moles and Compounds • What about a mole of water? • A mole of water (or 6.02 x 1023 molecules) weighs 18.0 grams! You can determine the molar mass of any compound by adding the molar mass of each atom or multiples of atoms!
Please note! A mole is 6.02 x 1023particles! A mole of copper will not have the same volume as a mole of sodium chloride!
And now it’s time for: Holey Moley Day!