The Mole: A Measurement of Matter Chemistry The Mole: A Measurement of Matter

Formula Mass Sum of the masses of all the atoms represented in a chemical formula Units are amu

Sample Find the formula mass for Calcium Hydroxide. The formula for Calcium Hydroxide is Ca(OH)2 1 Ca x 40.08 amu = 40.08 amu 2 O x 16.00 amu = 32.00 amu 2 H x 1.01 amu = 2.02 amu 74.10 amu

Try These Find the formula masses for the following compounds: H2O MgCl2 Fe2(SO4)3 P2O5 18.02 amu 95.21 amu 399.91 amu 141.94 amu

The Mole (mol) The number of atoms to get exactly 12 g of 12C It’s a number used to measure amount Can be used as a conversion factor 1 mol = 6.02 x 1023 particles Often called Avogadro’s number

Sample How many moles are 1.5 x 1024 atoms of He? ? mol He = 1.5x1024 atoms He 6.02x1023 atom He 1 mol He = 2.5 mol He

Try These How many moles are 3.0 x 1022 molecules of water? How many molecules of ammonia are in 1.6 mol of ammonia? How many atoms are in 4.7 mol of Argon? 0.050 mol 9.6 x 1023 molecules 2.8 x 1024 atoms

Molar Mass The mass of one mole of a substance The same quantity as atomic mass or formula mass but has g/mol as its units. Can be used as a conversion factor

Try These Determine the Molar Mass of the following compounds NaCl NH3 58.44 g/mol 17.04 g/mol