Question

What is the molar mass of acetic acid?

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 Acetic acid $\left({\mathrm{CH}}_3\mathrm{COOH}\right)$:

$$\begin{gathered} \mathrm{Molar}\mathrm{mass}\mathrm{of}{\mathrm{CH}}_3\mathrm{COOH}=\mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{C}+\mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{H}+\mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{O} \\ \mathrm{Molar}\mathrm{mass}\mathrm{of}{\mathrm{CH}}_3\mathrm{COOH}=\left(2\times 12.011\mathrm{g}{\mathrm{mol}}^{-1}\right)+\left(4\times 1.0079\mathrm{g}{\mathrm{mol}}^{-1}\right)+\left(16.00\mathrm{g}{\mathrm{mol}}^{-1}\times 2\right) \\ \mathrm{Molar}\mathrm{mass}\mathrm{of}{\mathrm{CH}}_3\mathrm{COOH}=24.022+4.0316+32=60.05\mathrm{g}{\mathrm{mol}}^{-1} \end{gathered}$$

Thus, the molar mass of acetic acid is $60.05\mathrm{g}{\mathrm{mol}}^{-1}$.