What is the mass percent of sodium (Na) in a formula unit of sodium hydrogen carbonate (NaHCO_3)?

• A. 27.37%
• B. 42.39%
• C. 11.20%
• D. 15.18%

Answer: (A)

Verified step by step guidance

1. Identify the chemical formula of sodium hydrogen carbonate, which is NaHCO\_3, and note the elements present: sodium (Na), hydrogen (H), carbon (C), and oxygen (O).
2. Find the atomic masses of each element from the periodic table: Na, H, C, and O. These values are typically given in atomic mass units (amu) or grams per mole (g/mol).
3. Calculate the molar mass of sodium hydrogen carbonate by summing the atomic masses of all atoms in the formula: \(\text{Molar mass} = M_{Na} + M_H + M_C + 3 \times M_O\).
4. Calculate the mass percent of sodium in the compound using the formula: \(\text{Mass \% of Na} = \left( \frac{M_{Na}}{\text{Molar mass of NaHCO\_3}} \right) \times 100\%\).
5. Express the result as a percentage to find the mass percent of sodium in sodium hydrogen carbonate.