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?