[kidd101]

Q#1)
A piece of nickel foil, 0.550 mm thick and 1.25 cm on each side, reacted with fluorine, F₂, to give a nickel fluoride. The density of nickel is 8.908 g/cm^3.
     a) How many moles of nickel foil was used?
     b) If you isolate 1.261 g of nickel fluoride, what is its formula?
     c) what is the stock system name of this compound?
Is the following calculation correct for 1a?:
Ni²⁺_(s) + F_2(g)  NiF₂
M_Ni = 58.690 g/mole
P_Ni = 8.908 g/cm³
T_Ni = 0.055 cm
V = 0.086 cm³
n_Ni = (P_Ni)/(M_Ni) * Volume
       (0.152 mol/cm³) * (0.086 cm³)

n_Ni = 0.013 mol


Q#2)
Uranium is used as a fuel, primarily in the form of uranium (VI) oxide, in nuclear power plants. The following calculations are based on uranium chemistry.
    A small quantity of uranium metal, 0.169g, was heated in air to between 800-900*c to give 0.199g of dark green oxide, U_xO_y.
          a)  How many moles of uranium metal were used?
          b) how many moles of U_xO_y were obtained?
Is this correct:
O₂ is L.R.
0.199 g UO₃ * (mol UO3)/(286.0273 g UO3) * (2 mol U)/(2 mol UO3) * (238.029 g U)/(1 mole U) = 0.166 g U
 U_avl. - U_used = 0.003 g U(s) = 1.23E-5 mol U_(s) (Q#2a)

thx in advance

[kidd101]

no help
for 1b. do you just take the mass of NiF2 and change it in to mol and balance it out?
M(NiF2) = 96.71 g/mol
n(NiF2) = 0.01304 mol

1c. Nickel(II) fluoride

[Borek]

Moles of Ni are OK.

Find number of moles of fluroide in the compound.

What is ratio of number of moles of F to number of moles of Ni?