Question

Metal carbonyls are molecular compounds. assume that you heat and decompose completely 1.322 g of fex(co)y to form 0.377 g of iron. what is the empirical formula of the compound?

Answer 1

We are given total of 1.322g of compound. The masses are therefore:

mass Fe = 0.377 g

mass CO = 1.322 – 0.377 = 0.945 g

Convert this to moles by dividing with molar mass:

moles Fe = 0.377 / 55.845 = 6.75 x 10^-3 mol

moles CO = 0.945 / 28 = 0.03375 mol

To get the empirical formula, divide the two by the lowest mol = 6.75 x 10^-3 mol, so that we get:

Fe = 1

CO = 5

Therefore:

Fe(CO)5