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A Chemist’s “Dozen” http://www.ccs.k12.in.us/chsteachers/VKundrat/MOLE_DAY_EXPLOD%5B1%5D.gif The particles that make up matter (ions, atoms, and molecules) are extremely small Only large amounts of these particles can be weighed. In order to simplify these large numbers we use the mole 1Mole = 6.022 x 1023 particles ▪ Particles can be atoms, molecules, ion, bananas, lollipops, etc. 1Mole = 6.022 x 1023 particles Particles can be atoms, molecules, ion, bananas 6.022 x 1023 is known as Avogadro’s Number Amedeo Avagadro 1776-1856 How does the mole get this specific value? The value of the mole is equal to the number of atoms in exactly 12 grams of pure carbon-12. ▪ 12g C = 1 mole C atoms = 6.022 x 1023 C atoms This definition gives a relationship between mass (grams) and the number of atoms (Avagadro’s number) A Road Map Grams Remember: The Molar Mass is the sum of the weights of each element in the compound. NH3 would be 1(14)+3(1)= 17 g/mol Atoms Mole E.g. How many atoms are in one mole of pennies? Avagadro’s Number 1 mole pennies 6.022 x 1023 pennies = 6.022 x 1023 pennies 1 mole pennies http://www.vectorjunky.com/gallery/m/Mole-with-Shovel.jpg E.g. How many grams are in 1 mole of sodium? 1 mol Na 23 g Na 1 mol Na = 23 grams sodium This is the Gram Formula Mass (gfm) ratio E.g. How many molecules are in 13 grams of H2SO4? Solve in two steps. Avagadro’s Number 13 g H2SO4 1 mol H2SO4 6.022 x 1023 molecules H2SO4 = 98 g H2SO4 1 mol H2SO4 Gfm = 7.988 x 1022 molecules H2SO4 E.g. How many moles are in 31 atoms of copper? 31 atoms 1 mol = 5.148 x 10-23 moles copper 6.022 x 1023 Avagadro’s Number http://farm5.static.flickr.com/4007/4212783868_9ba7287e6e.jpg