Empirical Formula

The empirical formula is the simplest whole number ratio between atoms in a compound. It is determined experimentally by measuring the mass of the elements that combine to form a compound.

A compound is found to contain 63. 55 % Ag, 8. 23 % N and 28. 24 % O A compound is found to contain 63.55 % Ag, 8.23 % N and 28.24 % O. Calculate the empirical formula. Assume that you have 100 g- that means 63.55 g Ag, 8.23 g N, and 28.24 g O When in doubt- mole it out! 63.55 g Ag x 1 mole 107.9 g = 0.5890 mol = 1 0.5879 mol 8.23 g N x 1 mole 14.0 g = 0.5879 mol AgNO3 = 1 0.5879 mol 28.24 g O x 1 mole 16.0 g = 1.765 mol = 3 0.5879 mol

A compound is found to contain 50. 07 % Cu, 16. 29 % P and 33. 64% O A compound is found to contain 50.07 % Cu, 16.29 % P and 33.64% O. Calculate the empirical formula. Double Rearrange 50.07 g Cu x 1 mole 63.5 g = 0.7885 mol = 1.5 = 3 0.5255 mol 16.29 g P x 1 mole 31.0 g = 0.5255 mol = 1 = 2 Cu3P2O8 0.5255 mol Cu3(PO4)2 33.64 g O x 1 mole 16.0 g = 2.103 mol = 4 = 8 0.5255 mol Only do this for ionic compounds Not for covalent! Braniac Alkali Metals

A compound is found to contain 46. 08 % C, 27. 0 % N and 27. 0 % O A compound is found to contain 46.08 % C, 27.0 % N and 27.0 % O. Calculate the empirical formula. 46.08 g C x 1 mole 12.0 g = 3.84 mol = 2.2749 x 7 = 16 1.688 mol 27.0 g N x 1 mole 14.0 g = 1.929 mol = 1.1428 x 7 = 8 1.668 mol 27.0 g O x 1 mole 16.0 g = 1.688 mol = 1 x 7 = 7 1.688 mol C16N8O7 Braniac Alkali Metals