An organic compound contains C,H,and O.The percentages of H and C are 6.73% H,and 39.99% C by mass.The molecular mass is 60.06 u.What is the molecular formula of the compound?

Question

Quizplus · Accepted Answer

The molecular formula is determined by first finding the empirical formula from the given percentages and then relating it to the molecular mass. Given 39.99% C, 6.73% H, and the rest being O (100% - 39.99% - 6.73% = 53.28% O), we calculate the moles of each element in 100 g of the compound: C (39.99 g / 12.01 g/mol = 3.33 mol), H (6.73 g / 1.01 g/mol = 6.66 mol), O (53.28 g / 16.00 g/mol = 3.33 mol). The ratio of C:H:O is approximately 1:2:1, making the empirical formula CH2O. The empirical formula mass of CH2O is 12.01 + (2*1.01) + 16.00 = 30.03 u. The molecular mass is given as 60.06 u, which is twice the empirical formula mass, indicating the molecular formula is C2H4O2, which corresponds to choice D when written with subscript notation.

An Organic Compound Contains C,H,and O