(NR) Nov. 18, 2010: Molar Mass (Mass of Atom)

- the mass (in grams) of 1 mole of a substance is called the molar mass.
- it can be determined from the atomic mass on the periodic table.
- measured in g/mol

  
Molar Mass of Compounds 

*REMEMBER SIGNIFICANT DIGITS

Element                           work                             Molar Mass

H2O                                       2(1.0) + 16.0                                        18.0 g/mol
NO2                                       14 + 2(16.0)                                         46.0 g/mol
NaCl                                       23.0 + 35.5                                          58.5 g/mol
FeO                                         55.8 + 16.0                                         71.8 g/mol
NaNO3                              23.0 + 14 + 3(16.0)                                  85.0 g/mol



Mole Conversions (converting between grams and moles)

- To convert between moles and mass we use molar mass as the conversion factor.
- be sure to cancel the appropriate units.