A sample of trifluoroacetic acid, C2HF3O2, contains 64.1 g of oxygen. Calculate the mass of the trifluoroacetic acid sample.

Answer 1

The molar mass of oxygen is 15.999 g/mol, so 64.1 g of oxygen converts to 4.00 moles of oxygen. For every mole of acid, there are two moles of oxygen. Since there are 4 moles of oxygen, there are two moles of acid. To find grams of acid, determine the molar mass of the acid and multiply by 2 moles. This results in an answer of 228 g.