1 The Mole

2 How you measure how much? How you measure how much? n You can measure mass, n or volume, n or you can count pieces. n We measure mass in grams. n We measure volume in liters. n We count pieces in MOLES.

3 Moles n Defined as the number of carbon atoms in exactly 12 grams of carbon- 12. n 1 mole is 6.02 x particles. n Treat it like a very large dozen n 6.02 x is called Avagadro’s number.

4 The Mole Song

5 Representative particles n The smallest pieces of a substance. n For a molecular compound it is a molecule. n For an ionic compound it is a formula unit. n For an element it is an atom.

6 Types of questions n How many oxygen atoms in the following? –CaCO 3 –Al 2 (SO 4 ) 3 n How many ions in the following? –CaCl 2 –NaOH –Al 2 (SO 4 ) 3

7 Types of questions n How many molecules of CO 2 are the in 4.56 moles of CO 2 ? n How many moles of water is 5.87 x molecules? n How many atoms of carbon are there in 1.23 moles of C 6 H 12 O 6 ? n How many moles is 7.78 x formula units of MgCl 2 ?

8 Gram Atomic Mass n The mass of 1 mole of an element in grams. n Same as formula mass on the periodic table

9 Examples n How much would 2.34 moles of carbon weigh? n How many moles of magnesium in g of Mg? n How many atoms of lithium in 1.00 g of Li? n How much would 3.45 x atoms of U weigh?

10 Examples n How many moles is 4.56 g of CO 2 ? n How many grams is 9.87 moles of H 2 O? n How many molecules in 6.8 g of CH 4 ? n 49 molecules of C 6 H 12 O 6 weighs how much?