The composition of NaHCO₃ shows that it contains 1.0 atom of Na, 1.0 atom of H and 3.0 atoms of O.
The molar mass of NaHCO₃ = ∑(no. of atoms x Atomic mass of the element).
Atomic mass of Na = 22.99 g/mole, atomic mass of H = 1.01 g/mole, atomic mass of C = 12.01 g/mole, and atomic mass of O = 16.00 g/mole.
Then, the molar mass of NaHCO₃ = (1.0 x 22.99) + (1.0 x 1.01) + (1.0 x 12.01) + (3.0 x 16.00) = 84.01 g/mole.
To get the percentage of each element using the relation: <em>% composition = [(no. of atoms x its atomic mass) / (molar mass of the compound)] x 100</em>.
The % of Na = (1.0 x 22.99) / (84.01) x 100 = 27.365 %.
The % of H = (1.0 x 1.01) / (84.01) x 100 = 1.20 %.
The % of C = (1.0 x 12.01) / (84.01) x 100 = 14.30 %.
The % of O = (3.0 x 16.00) / (84.01) x 100 = 57.13 %.