Question

An aqueous solution of orthophosphoric acid, H3PO4, has a measured density of 1.2089 g/mL and is 5.257 molal. How many moles of H3PO4 are there in one liter of this solution? 1) 0.4261 moles O2) 4.194 moles O 3) 4.349 moles 4) 5.152 moles 5) 6.355 moles

Answer 1

5.257 molal solution means 5.257 moles of the are present in 1000g - 1kg of water (solvent) density = 1.2089 g/m2 may of water = 1000g : үbtwoqМАЛ%buteo molar man of H3PO4 = 97.99 g/mol man of H3PO4 = moles x molar mass = 5.257 mol x 97.99 g/mol may = 515.19 Holoce of solution may of water t mans of Hapoy = 1000g + 515:19 = 1515.1g Volume of solution may = 1515. 19. density 1.2089 g/ml = 1253.3 mL In 1253.3 ml of solution, moles of H3PO4 = 5.257 mol In 1000 ml = 1L of solution, moles of HopOy = 5.257 mol x 1000 mL 1253.3 mL = 4.194 mol Hence option 2) is correct. Please Rate