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Homework Help: Help on empirical formula

  1. Feb 4, 2010 #1
    Vitamin B5 is called niacin or nicotinic acid. Its percentage composition by mass is (58.4% Carbon) (4.09% Hydrogen) (25.99% Oxygen) and (11.38% Nitrogen). What is the empirical formula of vitamin B5?
  2. jcsd
  3. Feb 6, 2010 #2
    Assume you have 100g of niacin. From your percentages, what mass of carbon, hydrogen, nitrogen and oxygen do you have? How many moles of each?
  4. Feb 8, 2010 #3


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    And Niacin is Vitamin B3, BTW. Minor mistake that won't really affect your problem.
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