1. Molar Mass and Percent Composition

2. Molar Mass Mass of 1 mol of a substance 128.21g NiF2 =_______ mol
On Periodic Table for elements
Must calculate for compounds
128.21g NiF2 =_______ mol

3. 59.49g (NH4)2HPO3=_______formula units

4. Hydrates—solids that contain a fixed number of H2O molecules as part of their structure
3.10 x 1023 formula units Na2(CO3)∙10H2O =____ g

5. % Composition Gives the % of each element in a compound.
Average atomic mass of compound divided by molar mass of compound and then multiplied by 100.
Make sure you keep track of how many of each element you have
All percentages need to add to 100%