Question

Match the following elements with their respective mass percentage in the compound ${\mathrm{NaHCO}}_3$

• A. 27.4 %
• B. 1.2 %
• C. 14.3 %
• D. 57.1 %

Answer 1

The molecular weight of${\mathrm{NaHCO}}_3$ is 23 + 1 + 12 + $3\times 16$ = 84 u
In 84 u -
mass % of $\mathrm{Na}$ = $\left(\frac{23}{84}\right)\times 100$= 27.4 %
mass % of $H$ = $\left(\frac{1}{84}\right)\times 100$= 1.2 %
mass % of $C$ = $\left(\frac{12}{84}\right)\times 100$ = 14.3 %
mass % of $O$ = $\left(\frac{3\times 16}{84}\right)\times 100$= 57.1 %