Question

1).Determine the number of moles represented by the given massof each of the following substances:
a).23.68 g of lead iodine,PbI2
b).0.791 g of propane,C3H8
c).3.45x10^2 g of potassium dichromate,K2Cr2O7
d).14.32g of calcium phosphate,Ca3(PO4)2
e).4.92 g of copper sulfate pentahydrate,CuSO4 X 5H2O

2).Calculate the mass represented by the given number of moles ofthe following substance:
4.35 X 10^-6 mol of iron (III)oxide,Fe2O3

3).Calculate the mass percent made up by each element in thefollowing compound :
phosphoric acid, H3PO4