This video shows step by step solutions to a few different percent composition problems.
You can view the transcript for “Percentage Composition” here (opens in new window).
Molecular and Empirical Formulas
Introduction to molecular and empirical formulas. The presenter shows both types of formulas for a variety of molecules. He also reviews the process of calculating molecular mass.
Formula from Mass Composition
How to figure out the empirical formula from a molecule’s mass composition.
Molecular and Empirical Formulas from Percent Composition
Presenter works through a multi-step problem to calculate molecular and empirical formulas from percent composition.
[NOTE: at 8:58 the presenter accidentally writes 6 instead of 2 (he says aloud “2 oxygens”), it is corrected it later]