34 A particular ore contains 578 calcium phosphate How many

34. A particular ore contains 57.8% calcium phosphate. How many pounds of ore must be processed to obtain 2.00 kg of phosphorus? HINT: 1 pound = 453.59 g a) 11.1 poundsb) 38.2 pounds c) 22.1 pounds d) 0.123 poundse) 12.8 pounds

Solution

34) Answer : b) 38.2 pounds

mass % Ca3(PO4)2 = 57.8 %

mass of Ca3(PO4)2 = 57.8 g

moalr mass of Ca3(PO4)2 = 310.2 g

mass of P = 61.95 g

310.2 g ---------------> 61.95 g P

?? g ----------------> 2000 g

mass of P = 2000 x 310.2 / 61.95

                = 10014.5 g

mass of ore = 10014.5 x 100 / 57.8

                    = 17325.95 g

mass of ore = 17325.95 g / 453.59

mass of ore = 38.2 pounds