Empirical/Molecular Notes

Empirical Formula A formula giving the proportions of the elements present in a compound but not the actual numbers or arrangement of atoms. Calculate the ratio of moles of each element in the compound Smallest whole number ratio becomes the subscripts

Determine the empirical formula for compound that has the following analysis: 66.0% barium and 34.0% chlorine BaCl2

A 0. 858g sample of an unknown substance is composed of 0 A 0.858g sample of an unknown substance is composed of 0.537g copper and 0.321g fluorine. CuF2

60.9% As and 39.1% S As2S3

Determine the empirical formula for compounds that have the following analyses: 80.38% bismuth, 18.46% oxygen, 1.16% hydrogen BiO3H3 12.67% aluminum, 19.73% nitrogen, and 67.60% oxygen AlN3O9

Molecular Formula a chemical formula based on analysis and molecular weight Multiple of empirical formula Need both molar mass (experimental mass) and empirical formula to find Find empirical first if not given

Determine the molecular formulas for compounds having the following empirical formulas and molar masses: C2H4S; experimental mass 179 C6H12S3

41.39% carbon, 3.47% hydrogen, and 55.14% oxygen; experimental molar mass 116.07 C4H4O4

C2H3O2; experimental molar mass 119 C4H6O4 54.53% Carbon, 9.15% hydrogen, and 36.32% oxygen; experimental molar mass 88 C4H8O2