If a sample of water contains 12 × 10^{23} oxygen atoms, how many moles of water molecules are present in the sample?

• A. 2 moles
• B. 6 moles
• C. 1 mole
• D. 0.5 mole

Answer: (A)

Verified step by step guidance

1. Recognize that each water molecule (H\_2O) contains exactly one oxygen atom. Therefore, the number of oxygen atoms is equal to the number of water molecules in the sample.
2. Identify Avogadro's number, which is the number of entities (atoms, molecules, etc.) in one mole: \$6.022 \times 10^{23}$ entities/mole.
3. Use the relationship between the number of molecules and moles: \(\text{moles} = \frac{\text{number of molecules}}{\text{Avogadro's number}}\).
4. Substitute the given number of oxygen atoms (which equals the number of water molecules) into the formula: \(\text{moles of water} = \frac{12 \times 10^{23}}{6.022 \times 10^{23}}\).
5. Simplify the fraction to find the number of moles of water molecules present in the sample.