Question

What is the molar mass of ${\mathrm{MgCl}}_2$? (in grams per mole)

Answer 1

Step1. Molar mass

The mass of $1$ mole of a substance is called its molar mass.

Step2. Formula for molar mass

Molar mass =$\text{The atomic mass of element × number of atoms given in subscript}$

Step3. Molar mass of ${\mathrm{MgCl}}_2$

Molar mass of ${\mathrm{MgCl}}_2$=$\left(\text{The atomic mass of Mg+}\left(\text{2×}\mathrm{The}\mathrm{atomic}\mathrm{mass}\mathrm{of}\text{Cl}\right)\right)$

=$\left(24.31+2\times 35.45\right){\text{g mol}}^{-1}$

= ${\text{95.21 g mol}}^{-1}$

Hence, the molar mass of ${\mathrm{MgCl}}_2$ is .${\text{95.21 g mol}}^{-1}$.