What is the mass percent of carbon in oxalic acid,H 2 C 2 O 4 ?

The molecular formula of oxalic acid is H2C2O4. The molar mass of the compound = 2(1.0079+1.008) + 2(12.011) + 4(15.999) = 90.034 g/mol. The mass percent of carbon in oxalic acid = (2 x 12.011 g/mol) / 90.034 g/mol x 100% = 26.7%. Therefore, the correct answer is (C).

What is the mass percent of carbon in oxalic acid,H 2 C 2 O 4 ?

The molecular formula of oxalic acid is H2C2O4. The molar mass of the compound = 2(1.0079+1.008) + 2(12.011) + 4(15.999) = 90.034 g/mol. The mass percent of carbon in oxalic acid = (2 x 12.011 g/mol) / 90.034 g/mol x 100% = 26.7%. Therefore, the correct answer is (C).