Answer:
Percent Composition (C) = 71.40%
Explanation:
To find the percent composition of carbon by mass, you need to (1) calculate the molar mass of C₂₀H₂₉FO₃ (using the atomic masses of each atom in the molecule), then (2) calculate the total amount of carbon in C₂₀H₂₉FO₃ (using the atomic mass of carbon), and then (3) calculate the percent composition of carbon.
(Step 1)
Atomic Mass (C): 12.011 g/mol
Atomic Mass (H): 1.008 g/mol
Atomic Mass (F): 18.998 g/mol
Atomic Mass (O): 15.999 g/mol
Molar Mass (C₂₀H₂₉FO₃):
20(12.011 g/mol) + 29(1.008 g/mol) + 18.998 g/mol + 3(15.999 g/mol)
= 336.447 g/mol
(Step 2)
Atomic Mass (C): 12.011 g/mol
Total Mass (C): 20(12.011 g/mol) = 240.22 g/mol
(Step 3)
mass of carbon
Percent Composition (C) = ----------------------------- x 100%
mass of molecule
240.22 grams
Percent Composition (C) = ----------------------------- x 100%
336.447 grams
Percent Composition (C) = 71.40%
