finding empirical and the molecular formulas of the compound...?

Question

A sample of a compound containing C,O and silver (Ag) weighed 1.372g. On analysis it was found to contain 0.288g O and 0.974g Ag. The molar mass of the compound is 308.8 g/mol. from this data how can I determine the empirical and the molecular formulas of the compound.

Answer 1

g of C = 1.372 - (0.288+0.974) = 0.065 g

M (Ag) = 108 g/mole
M (C) = 12 g/mole
M(O) = 16 g/mole

Ag moles = 0.974/108 = 0.009 moles Ag
C moles = 0.065/ 12 = 0.0054 moles C
O moles = 0.288/16 = 0.018 moles O

Ag moles/C moles = 1.67 Ag moles/ C mol (almost 2)
O moles/Ag moles = 2 O moles/Ag mol
O moles/Cmoles = 3.33 O moles/ C mol (almost 3 or 4)

According to these results, the empirical formula seems to be:

Ag2C2O4 (taking integers in each ratio above)

The molecular mass of the compound is 308.8 g/mol and according to the obtained empirical formula the molecular mass is 304 g/mol

308.8/304 = 1.015 (almost 1)

Conclusion: Molecular formula is

Ag2C2O4

That´s it!

Good luck!