Question

What is the molar mass of barium chloride $\left({\mathrm{BaCl}}_2\right)$ ?

Answer 1

Step 1: Molar mass:

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

Step 2: Formula for molar mass:

• $\mathrm{Molar}\mathrm{mass}=\mathrm{The}\mathrm{atomic}\mathrm{mass}\mathrm{of}\mathrm{element}\times \mathrm{number}\mathrm{of}\mathrm{atoms}\mathrm{given}\mathrm{in}\mathrm{subscript}$

Step 3: Molar mass of Barium chloride $\left({\mathrm{BaCl}}_2\right)$:

$$\begin{gathered} \mathrm{Molar}\mathrm{mass}\mathrm{of}{\mathrm{BaCl}}_2=\mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{Ba}+\mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{Cl} \\ \mathrm{Molar}\mathrm{mass}\mathrm{of}{\mathrm{BaCl}}_2=\left(137.34\mathrm{g}{\mathrm{mol}}^{-1}\right)+\left(2\times 35.45\mathrm{g}{\mathrm{mol}}^{-1}\right) \\ \mathrm{Molar}\mathrm{mass}\mathrm{of}{\mathrm{BaCl}}_2=137.34\mathrm{g}{\mathrm{mol}}^{-1}+70.9\mathrm{g}{\mathrm{mol}}^{-1}=208.23\mathrm{g}{\mathrm{mol}}^{-1} \end{gathered}$$

Thus, the molar mass of acetic acid is $208.23\mathrm{g}{\mathrm{mol}}^{-1}$.