What is the molecular formula of these compounds?

Question

(a) empirical formula HCO2, molar mass = 90.0 g/mol

(b) empirical formula C2H4O, molar mass = 88 g/mol

Answer 1

HCO2 has a molar mass of 1 + 12 + 2(16) = 45

90/45 = 2

Therefore the molecular formula is H2C2O4

(probably oxalic acid)

C2H4O has a molar mass of 2(12) + 4(1) + 16 = 44

88/44 = 2

The molecular formula is C4H8O2

Hope this helps.

--David