Question

What is the molar mass of ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{CO}}_3$?

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 ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{CO}}_3$

Molar mass of ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{CO}}_3$=$\left[\left(\text{The atomic mass of N+}\left(\text{4×}\mathrm{The}\mathrm{atomic}\mathrm{mass}\mathrm{of}\text{H}\right)\right)\times 2\right]+\mathrm{The}\mathrm{atomic}\mathrm{mass}\mathrm{of}\text{C}+3\times \mathrm{The}\mathrm{atomic}\mathrm{mass}\mathrm{of}\text{O}$

=$\left[\left(\text{14.0067+4×1.0079}\right)\times 2\right]{\text{g mol}}^{-1}+12.01{\text{g mol}}^{-1}\hspace{0.17em}+\left(3\times 16.00\right){\text{g mol}}^{-1}$

= $\left[\left(18.0383\right)\times 2\right]{\text{g mol}}^{-1}+12.01{\text{g mol}}^{-1}\hspace{0.17em}+48{\text{g mol}}^{-1}$

=${\text{36.0766 g mol}}^{-1}+12.01{\text{g mol}}^{-1}\hspace{0.17em}+48{\text{g mol}}^{-1}$

= ${\text{96.0866 g mol}}^{-1}$

= ${\text{96 g mol}}^{-1}$

Hence, the molar mass of ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{CO}}_3$ is ${\text{96 g mol}}^{-1}$.