Question

An unknown compound contains only C, H, and O. Combustion of 6.10 g of this compound produced 14.9 g of CO₂ and 6.10 g of H₂O. What is the empirical formula of the unknown compound?

Answer 1

Answer:

The answer to your question is   C₃H₃O

Explanation:

Data

Combustion of a compound C, H, O

mass = 6.10 g

mass CO2 = 14.9 g

mass of water = 6.10 g

Reaction

                     Cx Hy Oz   +   O2   ⇒     CO2   +   H2O

Process

1.- Calculate the moles of carbon

                          44 g of CO2   --------------  12 g of carbon

                           14.9 g of CO2 -------------   x

                            x = (14.9 x 12) / 44

                            x = 4.06 g

                          12 g of C    ------------------ 1 mol

                          4.06 g       ------------------- x

                          x = (4.06 x 1) / 12

                          x = 0.34 moles

2.- Calculate the moles of hydrogen

                           18 g of water -------------  1 g of hydrogen

                            6.10 g of water ----------   x

                            x = (6.10 x 1) / 18

                            x = 0.33 g

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

                           0.33 g     ----------------  x

                           x = (0.33 x 1) / 1

                           x = 0.33 moles of H

3.- Calculate the mass of oxygen

mass of Oxygen = 6.10 - 4.06 - 0.33

                            = 1.71 g

                          16 g of O ---------------  1 mol of O

                          1.71 g of O -------------   x

                          x = (1.71 x 1) / 16

                          x = 0.11 moles

4.- Divide by the lowest number of moles

Carbon   = 0.34 / 0.11  = 3                          

Hydrogen = 0.33 / 0.11 = 3

Oxygen = 0.11 /0.11 = 1

5.- Write the empirical formula

                                    C₃H₃O