What? That docent make any scene?
Number of moles of FeCl2 used = mass/ molar mass
Number of moles = 507/126.751 = 4.
If one mole of Fe reacts with two moles of sodium
Then 4 moles of Fe produces 8 moles of sodium.
Number of moles of sodium = mass/molar mass
Molar mass of sodium chloride = 23 +35.5 = 58.5 g/mol
Hence mass = 8 * 58.5 = 468 g. Hence Option A.
The mass in grams of nitric acid that is required to react with 454g C7H8 is 932.72 grams
calculation
find the moles of C7H8 used
moles = mass/molar mass
= 454 g/92 = 4.935 moles
balanced reacting equation
C7H8 +3 HNO3 = C7H5N3O6 +3 H20
by use of mole ratio between C7H8 to HNo3 which is 1:3 the moles of HNO3 =4.935 x3 = 14.805 moles
mass of HNo3 = moles x molar mass
= 14.805 x 63 = 932.72 grams
part B
the mass of C7H5N3o6 = 2045.5 grams
calculate the moles of C7H8
= 829 g/92 g/mol = 9.011 moles
by use of mole ratio between C7H8 to C7H5N3O6 which is 1:1 the moles of C7H5N3O6 is also = 9.011 moles
mass of C7H5N3O6 is therefore = moles x molar mass
=9.011 x227 = 2045.5 grams