What is the approximate mass percent of nitrogen and oxygen in nitrogen dioxide (NO_2)?

• A. Nitrogen: 50%, Oxygen: 50%
• B. Nitrogen: 30%, Oxygen: 70%
• C. Nitrogen: 20%, Oxygen: 80%
• D. Nitrogen: 44%, Oxygen: 56%

Answer: (B)

Verified step by step guidance

1. Step 1: Write down the molecular formula of nitrogen dioxide, which is \(\mathrm{NO_2}\), indicating 1 nitrogen atom and 2 oxygen atoms per molecule.
2. Step 2: Find the atomic masses of nitrogen and oxygen from the periodic table. Typically, nitrogen has an atomic mass of approximately 14.0 g/mol, and oxygen has an atomic mass of approximately 16.0 g/mol.
3. Step 3: Calculate the molar mass of \(\mathrm{NO_2}\) by adding the atomic masses of all atoms in the molecule: \(\mathrm{Molar\ mass} = (1 \times 14.0) + (2 \times 16.0)\) g/mol.
4. Step 4: Calculate the mass percent of nitrogen using the formula: \(\mathrm{Mass\%\ of\ N} = \left( \frac{\text{mass of N in the formula}}{\text{molar mass of } \mathrm{NO_2}} \right) \times 100\).
5. Step 5: Calculate the mass percent of oxygen similarly: \(\mathrm{Mass\%\ of\ O} = \left( \frac{\text{mass of O in the formula}}{\text{molar mass of } \mathrm{NO_2}} \right) \times 100\). These percentages should add up to approximately 100%.