THE MOLE H Chem. Fall 2013

What do these words mean? Pair = 2 Dozen = 12 Half = 0.5 Baker’s Dozen = 13 Gross = 144 Mole = 6.02 x 1023 (Also called Avagadro’s number)

The Mole One mole = 6.02 x 1023 = 602,000,000,000,000,000,000,000 of bananas, monkeys, stars, anything….

How many atoms are in 4.2 moles of carbon? 4.2 moles C x 6.02 x 1023 atoms C = 2.5 x 1024 atoms C 1 mole C How many atoms are in 4.2 moles of magnesium? 4.2 moles Mg x 6.02 x 1023 atoms Mg = 2.5 x 1024 atoms Mg 1 mole Mg

One mole of anything always has 6.02 x 1023 items in it.

Don’t write this Notice when we ask “how many” it is like asking how many baseballs are in 4.5 dozen and how many basketballs are in 4.5 dozen? It is the same number. The mole allows us to count numbers.

The Mole Example: How Many Molecules of water are in a mole of water molecules? 6.02 x 1023 molecules

The Mole You try it: How many molecules are in 1 mole of CO2 molecules? 6.02 x 1023 molecules

5.72 x 1024 atoms Ca 1 mole Ca = 9.50 moles Ca The Mole We can also go from number of particles to moles: (use unit analysis to show your work) How many moles of Ca in 5.72 x 1024 atoms of calcium? 5.72 x 1024 atoms Ca 1 mole Ca = 9.50 moles Ca 6.02 x 1023 atoms Ca

The Mole You try it: How many moles of Mg in 9.76 x 1023 atoms of magnesium?

Do Now: How many moles are in 4.27 x 1023 molecules of water?

Where does the number come from? The mole is defined by the number of molecules found in exactly 12 grams of carbon 12.