34) What is the mole fraction of phosphoric acid in a 20.5% (by mass) aqueous solution? A) 0.0474 B) 0.0905 C) 0.0453

To find the mole fraction of phosphoric acid in a 20.5% (by mass) aqueous solution, we need to follow these steps:1. **Determine the masses of each component in the solution:** - Let's assume we have 100 g of the solution. - The mass of phosphoric acid (H₃PO₄) is 20.5 g. - The mass of water (H₂O) is 79.5 g.2. **Calculate the number of moles of each component:** - Molar mass of H₃PO₄ = 3(1.01) + 31.00 + 4(16.00) = 97.99 g/mol - Molar mass of H₂O = 2(1.01) + 16.00 = 18.02 g/mol Number of moles of H₃PO₄: Number of moles of H₂O: 3. **Calculate the mole fraction of phosphoric acid:** Therefore, the mole fraction of phosphoric acid in the solution is approximately 0.0453.The correct answer is:C) 0.0453