Terephthalic acid, used in the production of polyester fibers and films, is composed of carbon, hydrogen, and oxygen. When 0.6943 g of terephthalic acid was subjected to combustion analysis it produced 1.471 g CO2 and 0.226 g H2O. What is its empirical formula?Group of answer choices C5H12O4C3H4O2C4H3O2C2H2O

To find the empirical formula, we first need to determine the moles of each element in the compound.

1. Determine the moles of Carbon (C) and Hydrogen (H) from the products of combustion:

   The molar mass of CO2 is approximately 44.01 g/mol, and it contains one mole of carbon. Therefore, the moles of carbon in 1.471 g of CO2 is (1.471 g / 44.01 g/mol) = 0.0334 mol.

   The molar mass of H2O is approximately 18.02 g/mol, and it contains two moles of hydrogen. Therefore, the moles of hydrogen in 0.226 g of H2O is (0.226 g / 18.02 g/mol) * 2 = 0.0251 mol.

2. Determine the moles of Oxygen (O):

   The original mass of the terephthalic acid was 0.6943 g. The mass of carbon and hydrogen in the compound can be found by multiplying the moles of each by their respective molar masses (12.01 g/mol for C and 1.01 g/mol for H). Subtracting these from the original mass gives the mass of oxygen in the compound.

   Mass of C = 0.0334 mol * 12.01 g/mol = 0.401 g Mass of H = 0.0251 mol * 1.01 g/mol = 0.025 g

   Mass of O = 0.6943 g - 0.401 g - 0.025 g = 0.268 g

   The moles of oxygen is then (0.268 g / 16.00 g/mol) = 0.0168 mol.

3. Determine the ratio of moles of C, H, and O:

   C:H:O = 0.0334 : 0.0251 : 0.0168

   To find the empirical formula, we divide each of these by the smallest value (0.0168) to get the ratio in whole numbers:

   C:H:O = 2:1.5:1

   Since we can't have half atoms in a formula, we multiply all numbers by 2 to get whole numbers:

   C:H:O = 4:3:2

So, the empirical formula of terephthalic acid is C4H3O2. Therefore, the correct answer is C4H3O2.