The foul odor of rancid butter is due largely to butyric acid, a compound containing carbon, hydrogen, and oxygen. combustion analysis of a 4.30-g sample of butyric acid pro- duces 8.59 g co2 and 3.52 g h2o. determine the empirical formula for butyric acid.

The answer to your question is:   C₂H₄O

Explanation:

Data

Butyric acid                 CxHyOz

mass = 4.30 g

mass CO2 = 8.59 g

mass H2O = 3.52 g

Empirical formula = ?

Molecular weight CO2 = 44g

Molecular weight H2O = 18 g

Reaction

                           CxHyOz + O2  ⇒   CO2 + H2O

Process

Find the mass and moles of carbon

                         44g of CO2  12 g of C

                         8.59g of CO2   x

                         x = 2.34 g of C

                        12 g of C   1 mol of C

                        2.34 g of C      x

                        x = 0.195 moles of carbon                      

Find the moles and mass of hidrogen

                        18 g of H2O  2 g of H

                        3.52 g of H2O     x

                        x = 0.39 g of H        

                        1 g of H    1 mol of H

                       0.39 g of H  x

                       x = 0.39 mol of H            

Find the mass and moles of oxygen

Mass of O = 4.30 - 2.34 - 0.39

                  = 1.57 g      

Moles of Oxygen  

                        16 g of O  1 mol

                         1.57 g of O  x

                         x = 0.098 moles            

Divide the number of moles by the lowest number

Carbon            0.195/0.098 = 1.98 ≈ 2

Hydrogen        0.39/0.098 = 3.97 ≈ 4

Oxygen           0.098/0.098 = 1

Finally

Empirical formula =    C₂H₄O