Question

An unknown compound was decomposed into 63.2 g carbon, 5.26 g hydrogen, and 41.6 g oxygen. what is its empirical formula?

Answer 1

Step 1:
           Divide mass of each element with its M.mass in order to find out moles.

                       C  =  63.2 g / 12 g/mol  =  Moles  =  5.26 moles

                       H  =  5.26 g / 1.008 g/mol  =  Moles  =  5.21 moles

                       C  =  41.6 g / 16 g/mol  =  Moles  =  2.6 moles

Step 2:
          Select moles of the element with least value and divide all moles of element by it,
                             C                H             O          
                       5.26/2.6  :  5.21/2.6  :  2.6/2.6

                          2.02     :     2.00     :       1

Result:
               Empirical Formula  =     C₂H₂O