To calculate the molar mass of NaHCO₃, we need to add the molar mass of each of its atoms.
This compound has 1 atom of Na, 1 of H 1 of C and 3 of O.
The molar mass of these atoms can be consulted on a periodic table, and they are:
[tex]\begin{gathered} M_{Na}=22.9898g/mol \\ M_H=1.0079g/mol \\ M_C=12.0107g/mol \\ M_O=15.9994g/mol \end{gathered}[/tex]So, the molar mass of NaHCO₃ is:
[tex]\begin{gathered} M_{NaHCO_3}=1\cdot M_{Na}+1\cdot M_H+1\cdot M_C+3\cdot M_O \\ M_{NaHCO_3}=(1\cdot22.9898+1\cdot1.0079+1\cdot12.0107+3\cdot15.9994)g/mol \\ M_{\mleft\{NaHCO_3\mright\}}=\mleft(22.9898+1.0079+12.0107+47.9982\mright)g/mol \\ M_{\mleft\{NaHCO_3\mright\}}=84.0066g/mol\approx84.01g/mol \end{gathered}[/tex]