Question

What is the molar mass of methane,${\mathrm{CH}}_4$?

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 ${\mathrm{CH}}_4$

Molar mass of ${\mathrm{CH}}_4$=$\left(\text{The atomic mass of Carbon+}\left(\text{4×}\mathrm{The}\mathrm{atomic}\mathrm{mass}\mathrm{of}\text{hydrogen}\right)\right)$

=$\left(12.01+4\times 1.0079\right){\text{g mol}}^{-1}$

=$16.0416{\text{g mol}}^{-1}$

$\simeq 16{\text{g mol}}^{-1}$

Hence, the molar mass of ${\mathrm{CH}}_4$ is $16{\text{g mol}}^{-1}$.