Using Conversion Factors

Just like a dozen represents 12 of something, such as donuts, iguanas, chemistry assignments, etc., a mole also represents an amount of something. It is 6.02 x 10 of something. A mole can represent 6.02 x 10 donuts, iguanas, toes, etc. In chemistry, it is normally used to represent an amount of atoms, ions, molecules, or formula units. Collectively, atoms, ions, molecules, or formula units are called representative particles. 23

Because chemists deal with such large amounts of particles, it is easier to work with moles of particles

amounts of particles can be expressed not only as moles, but as mass (grams), as volume (liters), and as individual particles (atoms, molecules, ions, formula units, etc.)

a measurement of a sample of a molecule, H2O for example, can be converted from mass to moles to particles to volume and back again to any unit of measurement desired O H

using the right conversion factors this is so cool!!

35 g Al

35 g Al ? moles Al

1 mol 35 g Al x 27 g

1 mol 35 g Al x 27 g 35 g Al x 1 mol 27g =

1 mol 35 g Al x 27 g 35 mol Al 27 = = 1.3 mols Al

? mass SiO2 0.8 moles SiO2

? mass SiO2 0.8 moles SiO2

0.8 moles SiO2 x 60.1 g SiO2 1 mole SiO2 = 0.8 x 60.1 g SiO2 = 48.1 g SiO2

200 g N2O ? molecules N2O

200 g N2O ? molecules N2O

200 g N2O x x 1 mole N2O 6.02 x 10 molecules N2O 44.0 g N2O 1 mole N2O 23 200 x 6.02 x 10 molecules N2O 44.0 23 = = 2.74 x 10 molecules N2O 24 this is so cool!!