Which of the following correctly represents the formula for calculating the molar mass of water (H_2O)?

• A. ext{molar mass of H} + ext{molar mass of O}
• B. 1 imes ext{molar mass of H} + 2 imes ext{molar mass of O}
• C. 2 imes ext{molar mass of O} + 1 imes ext{molar mass of H}
• D. 2 imes ext{molar mass of H} + 1 imes ext{molar mass of O}

Answer: (D)

Verified step by step guidance

1. Identify the chemical formula of water, which is \(\mathrm{H_2O}\), indicating there are 2 hydrogen atoms and 1 oxygen atom in each molecule.
2. Recall that the molar mass of a compound is calculated by summing the molar masses of each element multiplied by the number of atoms of that element in the formula.
3. Write the general formula for molar mass of water as: \$2 \times \text{molar mass of H} + 1 \times \text{molar mass of O}$.
4. Understand that the molar mass of hydrogen (H) and oxygen (O) are constants found on the periodic table, typically in units of grams per mole (g/mol).
5. Combine these values according to the formula to find the total molar mass of water, ensuring the correct coefficients (2 for H and 1 for O) are used.