Given a 2.5 kg solution of phosphoric acid and water (56 % phophoric acid, by mass), calculate the number of moles of phosphoric acid.

Answer 1

56% H3PO4 bu mass means 56 g H3PO4 in 100 g solution.
YOu have 2.5 kg or 2,500 g of the soln, therefore, you have
56 g H3PO4 x (2,500 g/100 g) = ?? g H3PO4.
Then number of moles = grams/molar mass.