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Khan Academy
Khan Academy: Chemistry: Formula From Mass Composition
Learn how to calculate the empirical formula of a compound by knowing the mass composition. The video gives two step-by-step examples of how to figure out the empirical formula. [12:58]
Khan Academy
Khan Academy: Chemistry: Molecular and Empirical Formulas
A video lecture explaining the difference between the molecular and empirical formula. The video also shows how to calculate the molecular mass of a compound. [15:54]