Chapter F, Problem F.4BST

Interpretation Introduction

Interpretation:

Molecular formula of oxalic acid has to be deduced if its molar mass is $90.0\text{g}\cdot {\text{mol}}^{-1}$ and the empirical formula is ${\text{CHO}}_{\text{2}}$.

Concept Introduction:

Empirical formula is the one that can be determined from the molar mass of the elements that is present in the compound and the mass percentage of the elements.  The mass percentage of the elements present in the compound is converted into the moles of each element considering the molar mass of each element.  The relative number of moles for each type of atoms is found out finally.

Molecular formula of a compound can be found if the empirical formula and molar mass of the compound is known.  The molar mass of compound is divided by the molar mass of the empirical formula in order to obtain the factor which is multiplied with the coefficients of empirical formula in order to obtain the molecular formula.