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Introduction to the Mole
Background
• When you buy eggs you usually ask for a _______ eggs.
• You know that one dozen of any item is ______.
Paper
• Paper is packaged by a ream.
• A ream of paper has 500 sheets.
• Why is it useful to use units like a dozen or a ream?
• What determines how many items should make up a particular unit?
One MOLE of anything has 602,200,000,000,000,000,000,000 items.
AVOGADRO’S NUMBER
• One MOLE of anything has 6.02 x 1023 items.–Items can be particles, atoms,
molecules, etc.
Converting Moles and Particles
• Write down what you are given.
• Set up a conversion factor to cancel units.
• 1 mole = 6.02 x 1023 ______
• Reminder: Units must be diagonal from each other in order to cancel!
• How many atoms of potassium make up two moles?
How many moles are 1.806 x 1024 atoms of iron?
• How many hydrogen atoms are in 2.5 moles of water?
• On the periodic table, the atomic mass given is the mass (in grams) of one mole of that atom.– Sodium (Na) Molar Mass = 22.99 g– Magnesium (Mg) = ____ g
Gram Formula Mass• The mass of one mole of a substance
• Sodium
• Potassium carbonate
• Barium hydroxide
• How many years would it take you to count to Avogadro’s Number if you counted one number per minute?