Question

What is the molar mass of potassium permanganate?

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 Potassium permanganate

The formula for Potassium permanganate is ${\mathrm{KMnO}}_4$.

Molar mass of ${\mathrm{KMnO}}_4$=$\left(\mathrm{The}\mathrm{atomic}\mathrm{mass}\mathrm{of}\text{K+}\mathrm{The}\mathrm{atomic}\mathrm{mass}\mathrm{of}\text{Mn+}\left(\text{4×}\mathrm{The}\mathrm{atomic}\mathrm{mass}\mathrm{of}\text{O}\right)\right)$

=$\left[39.10{\text{g mol}}^{-1}{\text{+54.94 g mol}}^{-1}\text{+}\left(\text{4×16.00}\right){\text{g mol}}^{-1}\right]$

=$158.04{\text{g mol}}^{-1}\hspace{0.17em}$

Hence, the molar mass of ${\mathrm{KMnO}}_4$ is $158.04{\text{g mol}}^{-1}\hspace{0.17em}$.