Question

certain alcohol contains only three elements, carbon, hydrogen, and oxygen. Combustion of a 40.00 gram sample of the alcohol produced 76.40 grams of CO2 and 46.96 grams of H2O. What is the empirical formula of the alcohol? Express your answer as a chemical formula.

Answer 1

Answer:

The answer to your question is:    C₂H₆O₁   = C₂H₆O

Explanation:

Data

CxHyOz

mass = 40 g  produced 76.40 g of CO2

                                       46.96 g of H2O

Empirical formula = ?

Process

                         CxHyOz    + O2    ⇒    CO2  + H2O

                         44g of CO2 --------------------  12 g of Carbon

                         76.40 g of CO2 --------------- x

                          x = 20.84 g of Carbon

                         12 g of Carbon ---------------  1 mol

                         20.84 g of C    ---------------   x

                         x = (20.84 x 1) / 12

                         x = 1.74 mol of Carbon

                        18 g of H2O --------------------  2 g of H

                        46.96 g of H2O --------------   x

                        x = (46.96 x 2) / 18

                        x = 5.22 g of H

                        1 g of H ------------------------  1 mol of H

                        5.22 g of H -------------------   x

                        x = 5.22 mol of H

Mass of Oxygen = 40 - 20.84 - 5.22g

                           = 13.94 g

                         16 g of Oxygen ----------------  1 mol

                         13.94 g of O --------------------   x

                         x = 0.87 mol of O

Divide by the lowest number of moles

Carbon = 1.74 / 0.87 = 2

Hydrogen = 5.22 / 0.87 = 6

Oxygen = 0.87 / 0.87 = 1

                           

Empirical formula

                                 C₂H₆O₁   = C₂H₆O