CHEM 1021 Lecture Notes - Lecture 18: Fluorine, Chemical Formula, Molar Mass
Document Summary
Mass percent data can be used to determine the empirical formula of a compound. Smallest whole # ratio of one element to another in a compound. Mass or mass percent data gives us the empirical formula not the molecular formula. To get molecular formula we need more information: molar mass. Benzene: empirical formula ch: molar mass benzene = 78 g/mol o o. The empirical formula for a compound is c5h3 (63 g/mol). Freon-12 mass 9. 933% carbon, 58. 63% chlorine, and the rest fluorine. Carbon: (9. 933 g c)(1 mol c/ 12. 01 g) = 0. 82706 mol c. Chlorine: (58. 63 g cl)(1 mol cl/ 35. 45 g) = 1. 65444 mol cl. Fluorine: 100-9. 933-58. 63 = 31. 437 g f (31. 44 g f) (1 mol f/19. 00g) = 1. 65474 mol f. Carbon is smallest number moles divide everything by carbon (1. 65444 mol cl/0. 82706 mol c) = 2 mol cl/ 1 mol c. Carbon: (7. 568 g c)(1 mol c/12. 01g) = 0. 63014 mol c.
