The mass ratio of zinc to iodine in zinc iodide is 0.25755 .
Given: mass of zinc consumed = 1.05 g; mass of iodine consumed = 1.98 g; mass of zinc iodide = 2.45 g
Implied: atomic mass of zinc = 65.38 g/mole; atomic mass of iodine = 126.92 g/mole
Required: mass ratio of zinc to iodine in zinc iodide
Strategy:
Obtain the mass percent of zinc in zinc iodide.
Solution:
molar mass of zinc iodide = 319.22 g/mole
zinc = 1 (atom) x 65.38 g/mole = 65.38 g/mole
iodine = 2 (atoms) x 126.92 g/mole = 253.84 g/mole
Now that we know the molar mass of zinc iodide we will now compute for the mass percent of zinc in zinc iodide. We can do this by dividing the atomic mass of zinc by the molar mass of zinc iodide.
[ (65.38 g/mole) / (319.22 g/mole) ] x 100 % = 20.48 %
This means that there is 0.50176 g of zinc and 1.94824 g of iodine in the zinc iodide that was formed after the reaction.
Now that we know the mass of zinc and the mass of iodine in the zinc iodide that was formed we can divide the mass of zinc by the mass of iodine to get the mass ratio.
0.50176 g / 1.94824 g = 0.2575452716 or 0.25755