Empirical Formula from Stoichiometry?

[jacksonpeeble]

Empirical Formula from Stoichiometry!?

Homework Statement

More than 1 billion pounds of adipic acid (MW 146.1 g/mol) is manufactured in the US each year. Most of it is used to make synthetic fabrics. Adipic acid contains only C, H, and O. Combustion of a 1.6380g sample of adipic acid gives 2.960g of CO2 and 1.010 g of H2O. What is the simplest formula for adipic acid? What is its molecular formula?

Homework Equations

(Adipic Acid) + O2 -> CO2 + H2O

The Attempt at a Solution

Convert to .0561 mol H2O
Convert to .0673 mol Co2
Convert to .0112 mol adipic acid using stoichiometry (I understand this part).

 

[iRaid]

Divide each of the moles by the least amount (adipic acid), then you'll get (roughly) even numbers, which is the empirical formula.

 

[Borek]

Use given masses of water and carbon dioxide to calculate masses of hydrogen and carbon in the sample of adipic acid - you will see the sample weighted more. Missing mass is the oxygen. Then calculate moles of H, C and O (not H₂, C and O₂) and find their ratio as iRaid suggested.