Answer:
In one liter of solution, there are 4.194 moles of H₃PO₄
Explanation:
A molal solution contains 1 mole of solute in 1 Kg of solvent.
A aqueous 5.257 molal solution of H₃PO₄ will contain 5.257 moles of H₃PO₄ in 1 Kg or 1000 g of water
.
Molar mass of H₃PO₄ = 98 g/mol
Therefore mass of H₃PO₄ = number of moles * molar mass
mass of H₃PO₄ = 5.257 mol * 98 g/mol = 515.2 g
mass of solution = mass of solute + mass of solvent
mass of solution = 515.2 + 1000 = 1515.2 g
Volume of solution = mass of solution / density of solution
Volume of solution = 1515.2 / 1.2089 = 1253.4 mL
Molarity of solution = number of moles / volume (L)
Molarity of solution = 5.257 / 1.2534 L = 4.194 mol/L
Therefore, in one liter of solution, there are 4.194 moles of H₃PO₄
