To calculate the molar mass of phosphoric acid (H₃PO₄), we need to sum the molar masses of all the atoms in the formula.
- Hydrogen (H): 3 atoms × 1.01 g/mol = 3.03 g/mol
- Phosphorus (P): 1 atom × 30.97 g/mol = 30.97 g/mol
- Oxygen (O): 4 atoms × 16.0 g/mol = 64.0 g/mol
Now, add these values together:
\[ 3.03 , \text{g/mol (H)} + 30.97 , \text{g/mol (P)} + 64.0 , \text{g/mol (O)} = 98.0 , \text{g/mol} \]
Therefore, the molar mass of phosphoric acid (H₃PO₄) is 98.0 grams.
The correct answer is:
D. 98.0 grams