53I 95Am 22Ti75Re1D 2 Mastering Chemistry New assignment will be posted later today Due Tomorrow by 11:59PM

Empirical Formulae The simplest whole number ratio of atoms in a molecule Example: molecular formula = C6H12O2 empirical formula = C3H6O Example: molecular formula = C16H32O2N4 empirical formula = C8H16ON2 Example: molecular formula = KMnO4 empirical formula = KMnO4

Calculating Empirical Formulae What is the empirical formula of a compound that is made up of 10.95g C, 29.25g O, and 34.75g F? Step 1: convert each mass to MOLES Step 2: divide EACH by the smallest!!

Calculating Empirical Formulae What is the empirical formula of a compound that is made up of 10.95g C, 29.25g O, and 34.75g F? So we have 1 mol C, 2 mol O, and 2 mol F Step 3: if each is a whole number, write the empirical formula CO2F2

Calculating Empirical Formulae What is the empirical formula of a compound that is made up of 32.79% Na, 13.02% Al, and 54.19% F? Step 1: assume 100 g THEN convert each mass to MOLES Step 2: divide EACH by the smallest!!

Calculating Empirical Formulae What is the empirical formula of a compound that is made up of 32.79% Na, 13.02% Al, and 54.19% F? So we have 3 mol Na, 1 mol Al, and 6 mol F Step 3: if each is a whole number, write the empirical formula Na3AlF6

Calculating Empirical Formulae What is the empirical formula of a compound that is made up of 62.1% C, 5.21% H, 12.1% N, and 20.7% O? Step 1: assume 100 g THEN convert each mass to MOLES Step 2: divide EACH by the smallest!!

Calculating Empirical Formulae What is the empirical formula of a compound that is made up of 62.1% C, 5.21% H, 12.1% N, and 20.7% O? So we have 6 mol C, 6 mol H, 1 mol N, and 1.5 mol O Step 3: if each is a whole number, write the empirical formula Step 3a: multiply EACH ELEMENT by the smallest number that will make all of them whole numbers C6H6NO1.5 O 1.5 x 2 = 3 C 6 x 2 = 12 H 6 x 2 = 12 N 1 x 2 = 2 C12H12N2O3

What is the empirical formula of a compound made up of 74. 01% C, 5 What is the empirical formula of a compound made up of 74.01% C, 5.23% H, and 20.76% O? Step 1: assume 100 g THEN convert each mass to MOLES Step 2: divide EACH by the smallest!!

What is the empirical formula of a compound made up of 74. 01% C, 5 What is the empirical formula of a compound made up of 74.01% C, 5.23% H, and 20.76% O? So we have 4.75 mol C, 4 mol H, and 1 mol O Step 3: If all of the subscripts are NOT whole numbers, then multiply EACH ELEMENT by the smallest number that will make all of them whole numbers C4.75H4O multiply EACH of the subscripts by 4! H 4 x 4 = 16 O 1 x 4 = 4 C 4.75 x 4 = 19 C19H16O4