Chapter 3, Problem 3.34P

Interpretation Introduction

Interpretation:Molecular formula of menthol should be written.

Concept introduction:An empirical formula depicts the ratio of simplified whole-number of atoms contained in a molecule. The molecular formula depicts exact number of each atom found in a molecule.

The steps to determine empirical formula are stated as follows:

Divide mass of element by its molar mass to convert mass to moles as follows:

  $\text{Amount}\left(\text{mol}\right)=\left(\text{Given mass}\left(\text{g}\right)\right)\left(\frac{1\text{ mol}}{\text{No}\text{. of grams}}\right)$

Number of moles thus calculated is written as subscript of element’s symbol and this results in a preliminary empirical formula.

In order to convert the moles to the whole number subscripts, each subscript is divided by the smallest subscript. Finally, empirical formula can be simply written from the molar ratio of each element specified at the superscript of each symbol present in the compound.

The formula to calculate the whole number multiple is as follows:

  $\text{Whole}-\text{number multiple}=\frac{\text{Molar mass of compound}}{\text{Empirical formula mass}}$

The product of this whole number with the subscript of each element results in the molecular formula.