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WHAT IS A MOLE?. 602214199000000000000000 6.02 x 10 23. Mole Facts. 6.02 X 10 23 Pennies: Would make at least 7 stacks that would reach the moon. 6.02 X 10 23 Watermelon Seeds: Would be found inside a melon slightly larger than the moon.
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WHAT IS A MOLE? • 602214199000000000000000 • 6.02 x 1023
Mole Facts • 6.02 X 1023 Pennies: Would make at least 7 stacks that would reach the moon. • 6.02 X 1023 Watermelon Seeds: Would be found inside a melon slightly larger than the moon. • 6.02 X 1023 Blood Cells: Would be more than the total number of blood cells found in every human on earth. • 1 Liter bottle of Water contains 55.5 moles H20
A Brief History… • Amadeo Avogadro was an Italian physics professor who proposed in 1811 that equal volumes of different gases at the same temperature contain equal numbers of molecules • Josef Loschmidt, an Austrian high school teacher,in 1865, calculated the number of molecules in one cm3 of gaseous substance to be somewhere around 2.6 x 1019 • J.Perrin (1908) estimated the value to be between 6.5 x 1023 and 6.9 x 1023 • Rutherford and Geiger used radioactive methods: 6.2 x 1023 • The best modern values for what we now call "Avogadro's Number" are the result of the x-ray diffraction measurement of lattice distances in metals and salts.
Definition of a Mole • The amount of atoms in 12.0 grams of Carbon 12 (6.02 x 1023 atoms known as Avogadro’s number). • A sample of any element with a mass equal to that element's atomic weight (in grams) will contain precisely one mole of atoms (6.02 x 1023 atoms).
How do we determine MOLAR MASS? • Molar Mass: Mass in grams of one mole of that substance • What is the molar mass of H2O? 2 Hydrogen atoms: 2 x 1g = 2g 1 Oxygen atom: 1x 16g = 16g 1 mole H2O = 18g • What is the molar mass of CO2? • Fe2O3?
Why is the mole an important unit in chemistry? • Atoms and molecules react with one another particle by particle • The mole is the translation factor between weights and numbers of particles
How do we convert mass to particles? How many moles in 10 g of O2? 10g O2 x 1 mole 32g = 0.3125 mol How many molecules in 55 g of H2O? 55g H2O x 1mole x 6.02 • 1023 18g 1mole = 18.4 • 1023 = 1.84 • 1024 molecules