How many molecules are present in 48.0 grams of oxygen gas (O_2)?

• A. 1.81 × 10^{24} molecules
• B. 3.01 × 10^{24} molecules
• C. 9.04 × 10^{23} molecules
• D. 6.02 × 10^{23} molecules

Answer: (A)

Verified step by step guidance

1. Identify the molar mass of oxygen gas (O\_2). Since each oxygen atom has an atomic mass of approximately 16.00 g/mol, the molar mass of O\_2 is calculated as \$16.00 \times 2 = 32.00$ g/mol.
2. Calculate the number of moles of O\_2 in 48.0 grams using the formula: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}}\). Substitute the values to get \(\text{moles} = \frac{48.0}{32.00}\).
3. Use Avogadro's number to convert moles to molecules. Avogadro's number is \$6.022 \times 10^{23}\( molecules per mole, so multiply the number of moles by this constant: \)\text{molecules} = \text{moles} \times 6.022 \times 10^{23}$.
4. Set up the full expression combining the previous steps: \(\text{molecules} = \left( \frac{48.0}{32.00} \right) \times 6.022 \times 10^{23}\).
5. Perform the multiplication to find the total number of molecules present in 48.0 grams of oxygen gas.