What is the molecular formula of a compound with the empirical formula C2H3N if its molar mass is about 123.15 g/mole? For your answer simply put subscripts directly after the element's symbol. You do not need to put anything for a subscript of '1'. For example, if your answer is supposed to be 'C2H2N2' then you would input 'C2H2N2'. Your answer should be written Carbon first, Hydrogen second, and Nitrogen third.