# Oxalic acid is 26.68% carbon, 2.24% hydrogen, and the remainder oxygen, what is its empirical formula?

$C H {O}_{2}$ is the empirical formula for oxalic acid.
Assume 100 g of acid. Breaking it down into its components, there are (26.68*g)/(12.01 *g*mol^-1*C); (2.24*g)/(1.00794 *g *mol^-1*H); (71.08*g)/(16.00*g*mol^(-1)*O) $=$ $C : H : O$ $=$ $2.22 : 2.22 : 4.44$ $=$ $1 : 1 : 2$.
Therefore, empirical formula of oxalic acid is $C H {O}_{2}$. If its molecular mass is $90.03 \cdot g \cdot m o {l}^{-} 1$, what is its molecular formula?