Molecular Formulas 1.Find empirical formula 2.Calculate molar mass of empirical formula 3.Molar mass of compound / molar mass of empirical formula (we’ll call this the factor) 4.Multiply subscripts by factor to get molecular formula
Molecular Formula A compound is found to have an empirical formula of C 2 H 3 O 2. The molar mass of the compound has g/mol. What is the molecular formula? –Molar mass of C 2 H 3 O 2 C 2 H 3 O 2 = 2x12 + 3x1 + 2x16= 59 g/mol –Molar mass of compound / molar mass of empirical / 59 = 2
Molecular Formula A compound was found to contain g carbon and g of hydrogen. The molar mass of the compound is 58.12g/mol. Determine the molecular formula C= / 12 = / = 1 x 2 = 2 H= / 1 = / = 2.5 x 2 = 5 C 2 H 5 = 2x12 + 5x1 = /29 = 2 C 2 H 5 x2 C 4 H 10
Molecular Formula Practice I 1. Analysis of a chemical used in photographic developing fluid indicates a chemical composition of 65.45% C, 5.45% H, and 29.09% O. The molar mass is found to be 110 g/mol. Determine the molecular formula.
Molecular Formula Practice I 2. A compound was found to contain g carbon and g hydrogen. The molar mass of the compound is g/mol. Determine the molecular formula.
Molecular Formula Practice I 3. A colorless liquid composed of 46.68% nitrogen and 53.32% oxygen has a molar mass of g/mol. What is the molecular formula?