molecular formula a wholenumber multiple of an empirical

molecular formula: a whole-number multiple of an empirical formula… …showing the total number of each atom in a molecule formaldehyde CH 2 O acetic acid C 2 H 4 O 2 glucose C 6 H 12 O 6 all same empirical formula: (same ratio of atoms) CH 2 O

Calculate the molecular formula of a compound with the empirical formula CH 4 N and a molar mass of 60. 0 g/mol. molecular mass = multiple of emp. form. empirical mass 1(C) + 4(H) + 1(N) = 12. 01 + 4(1. 01) + 14. 01 = 30. 06 g/mol 60. 0 = 1. 996 ≈ 2 30. 06 2 (CH 4 N) = C 2 H 8 N 2 multiple of emp. form.

Calculate the molecular formula of benzene with the empirical formula CH and a molar mass of 78 g/mol. molecular mass = multiple of emp. form. empirical mass 1(C) + 1(H) = 12. 01 + 1. 01 = 13. 02 g/mol 78 = 5. 991 ≈ 6 13. 02 6 (CH) = C 6 H 6 multiple of emp. form.

Quick Quiz. 1. True or False: A molecular formula can be the same as an empirical formula. Example: Formaldehyde has the empirical formula CH 2 O, which is the formula of the actual molecule.

Quick Quiz. 2. Determine the molecular formula of a compound with 40. 0 % C, 6. 70 % H, and 53. 3 % O by mass that has a CH 2 O molecular mass of 60 g/mol. A. C 2 H 4 O 2 B. CH 2 O C. C 2 H 3 O D. C 2 H 4 O mol C = 1 C 40. 0 g C x 1 mol C = 3. 33 ____ 12. 01 g C 3. 33 mol H = 2 H 6. 70 g H x 1 mol H = 6. 63 _____ 1. 01 g H 3. 33 ____ mol O = 1 O 53. 3 g O x 1 mol O = 3. 33 16. 00 g O 60 = 2 30. 03 2 (CH 2 O) =