Verified answer

we are not asked for the empirical formula so there is a much more elegant solution to this problem

the mass of each element in a mole can be calculated from the percentage of the molar mass

mass of C in 1 mole = 26.10% of 46.02g = 12g of C or 1 mole of C

mass of H = 4.38% of 46.02g = 2.0 g or 2 moles of H

mass of O = 69.52% of 46.02g = 32g og O or 2 moles of O

we now have the actual number of moles of each element in a mole of the compound

so the molecular formula is CH2O2

as you can see a much simpler solution .... 3 lines and easy to remember for your exams

Assume 100 g of formic acid is present. Therefore:

C = 26.10 g

H = 4.38 g

O = 69.52 g

Convert to moles:

C = 26.10 g / 12.011 g/mol = 2.173

H = 4.38 g / 1.008 g/mol = 4.345

O = 69.52 g / 16.00 g/mol = 4.345

Divide by lowest:

C = 2.173 / 2.173 = 1

H = 4.345 / 2.173 = 2

O = 4.345 / 2.173 = 2

Empirical formula = CH2O2

The empirical formula weighs 12 + 2 + 32 = 46

46.02 / 46 = 1

The molecular formula of formic acid is the same as the empirical formula and is usually written HCOOH.

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Molar Mass Of Formic Acid