1. Formula Mass of Compounds

2. Molar mass of an element
Molar mass = mass in grams of 1 mole of any pure substance.
Molar mass of an element numerically equal to atomic mass but units change to grams per mole.

3. Molar mass of elements
Na has an atomic mass of amu so its molar mass = grams
K has an atomic mass of amu so its molar mass = grams.
Ca has an atomic mass of amu so its molar mass = grams.

4. Molar mass
Also called formula mass.
Or gram formula mass.

5. Molar Mass of Compounds
= sum of the masses of the atoms in the formula.
Round atomic masses to the nearest tenth.
Ex: H2O
2 X H = 2 X 1.0 = 2.0
1 X O = 1 X 16.0 = 16.0
Sum = = 18.0

6. Molar Mass of Compounds
Try CH4
1 X C = 1 X 12.0 = 12.0
4 X H = 4 X 1.0 = 4.0
Sum = = 16.0

7. Molar Mass of Compounds
Try CO2
1 X C = 1 X 12.0 = 12.0
2 X O = 2 X 16.0 = 32.0
Sum = = 44.0

8. Molar Mass of Compounds
Try NaCl
1 X Na = 1 X 23.0 = 23.0
1 X Cl = 1 X 35.5 = 35.5
Sum = = 58.5

9. Molar Mass of Compounds
Try C6H12O6
6 X C = 6 X 12.0 = 72.0
12 X H = 12 X 1.0 = 12.0
6 X O = 6 X 16.0 = 96.0
Sum = = 180.0

10. Molar Mass of Compounds
Try Cu(OH)2
1 X Cu = 1 X 63.5 = 63.5
2 X O = 2 X 16.0 = 32.0
2 X H = 2 X 1.0 = 2.0
Sum = = 97.5

11. Molar Mass of Compounds
Try Al(NO3)3
1 X Al = 1 X 27.0 = 27.0
3 X N = 3 X 14.0 = 42.0
9 X 0 = 9 X 16.0 = 144.0
Sum = = 213.0