Question

Where can formula mass be applicable?

Answer 1

Formula unit mass:

• “The formula unit mass of a substance is a sum of the atomic masses of all atoms in a formula unit of a compound.”
• For example, the formula unit mass of Sodium chloride$\left(\mathrm{NaCl}\right)$ is expressed below:

$$\begin{gathered} \mathrm{Formula}\mathrm{unit}\mathrm{mass}\mathrm{of}\mathrm{NaCl}=\mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{Na}+\mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{Cl} \\ \mathrm{Formula}\mathrm{unit}\mathrm{mass}\mathrm{of}\mathrm{NaCl}=\left(1\times 23\right)+\left(1\times 35.5\right)=58.5\mathrm{u} \end{gathered}$$

Application of formula unit mass:

• The formula unit mass is applicable for ionic compounds such as Sodium chloride.
• It is used for stoichiometric measurements of any ionic/covalent network solid compound.