From the periodic table:
molar mass of Sn = 118.71 grams
molar mass of F = 18.99 grams
This means that:
molar mass of SnF2 = 118.71 + 2(18.99) = 156.69 grams
Therefore, 156.69 grams of SnF2 contains 37.98 grams of F. To know the amount of F in 36.5 grams of the compound, we will simply do a cross multiplication as follows:
mass of F = (36.6 x 37.98) / 156.69 = 8.847 grams
In Ni(CO)₄ the stoichiometry of Ni to C is 1:4
for every 4 atoms of C is attached to one Ni atom.
this means that if there are 4 atoms of C - 1 atom of Ni
in 5.23 x 10²⁴ atoms of C -1/4 x 5.23 x 10²⁴ atoms of Ni
= 1.3075 x 10²⁴ atoms of Ni
the number of atoms rounded off to the second decimal place = 1.31 x 10²⁴ atoms
correct answer is E
