The laboratory analysis of an organic compound determined the mass percent composition to be 75% carbon (C = 12), and 25% hydrogen (H = 1). What is the empirical formula of this compound?

CH4 (Methane)

Explanation:

The compound is found to be composed of 75% carbon and 25% hydrogen.

100 g of the compound contains 75 g of carbon and 25 g of hydrogen.

The atomic masses of carbon and hydrogen are 12 g/mol and 1 g/mol respectively.

The number of moles of C =   12 g/mol  /75 g   = 6.25 moles

The number of moles of H =   1 g/mol  / 25 g  = 25 moles

The mole ratio C:H=6.25:25=1:4

The empirical formula of the compound is CH  4

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