Commercial perchloric acid is 70.0% by mass,HClO₄(aq).Calculate the mole fraction of perchloric acid in the solution.

Question

Quizplus · Accepted Answer

The mole fraction of perchloric acid in the solution can be calculated by first determining the moles of HClO4 and water in a given mass of the solution, then using these values to find the mole fraction. Given that commercial perchloric acid is 70.0% by mass HClO4, for a 100 g sample, we have 70 g of HClO4 and 30 g of water (H2O).The molar mass of HClO4 is approximately 100.46 g/mol, and the molar mass of water is 18.015 g/mol.Moles of HClO4 = mass / molar mass = 70 g / 100.46 g/mol ≈ 0.697 molesMoles of H2O = mass / molar mass = 30 g / 18.015 g/mol ≈ 1.665 molesTotal moles = moles of HClO4 + moles of H2O ≈ 0.697 + 1.665 ≈ 2.362 molesMole fraction of HClO4 = moles of HClO4 / total moles ≈ 0.697 / 2.362 ≈ 0.295

Commercial Perchloric Acid Is 70