What is the mass percent of oxygen in sodium carbonate (Na2CO3)?

• A. 48.0%
• B. 30.4%
• C. 16.0%
• D. 53.0%

Answer: (A)

Verified step by step guidance

1. Identify the chemical formula of sodium carbonate, which is \(\mathrm{Na_2CO_3}\), and note the elements present: sodium (Na), carbon (C), and oxygen (O).
2. Determine the atomic masses of each element from the periodic table: sodium (Na) approximately 23 g/mol, carbon (C) approximately 12 g/mol, and oxygen (O) approximately 16 g/mol.
3. Calculate the molar mass of sodium carbonate by summing the contributions of each element: \$2 \times 23\( for sodium, \)1 \times 12\( for carbon, and \)3 \times 16\( for oxygen. Express this as \)M_{\mathrm{Na_2CO_3}} = 2(23) + 12 + 3(16)$.
4. Calculate the total mass of oxygen atoms in one mole of sodium carbonate, which is \$3 \times 16$ g.
5. Find the mass percent of oxygen by dividing the total mass of oxygen by the molar mass of sodium carbonate and multiplying by 100%, using the formula: \(\text{Mass \% O} = \frac{3 \times 16}{M_{\mathrm{Na_2CO_3}}} \times 100\%\).