PPT-Percent Composition, Empirical Formulas, Molecular Formulas

Percent Composition Percent Composition the percentage by mass of each element in a compound note not the ratio of elements in the compound Law of Definite Proportions compounds always contain the same proportions of elements by mass. Molecular Formulas. Let’s use those mole conversions!. Empirical formula . tells you the lowest ratio of atoms within a molecule. Molecular formula . tells you the actual ratio of atoms within a molecule. Do Now: from last years regents. Chemical Formulas. Tell . type. & . number. atoms in compound. Microscopic level: . Formula gives atom ratios. Macroscopic level: . Formula gives mole ratios. EXAMPLE. Chemistry GT 3/20/15. Drill. Calculate the percent composition of Na. 2. SO. 4. .. HW: Molecular Formula WS (pg. 4). MM. =142.05 . g. /mol. 32.37% Na, 22.58% S, 45.05% O. Chem. Joke of the Day. The photon checked into a hotel. What did it say when the bellhop asked for its bag?. and Scientific Thinking . Brendan Conway. Corrine Vicari. Kaitlyn Creel. Matt Graham . Empirical Thought . Empirical thinking depends on past habit.. Based on observation and experience.. Ex. A-“It will probably rain tomorrow”. Percent Composition. . Percent Composition – . the percentage by mass of each element in a compound . Percent =. _______. Part. Whole. x 100%. So…. Percent composition. of a compound or =. molecule. Represents the . actual. number of . atoms. of each . element. in . compound. Not necessary for . ionic compounds. Necessary for . covalent compounds. The molecular formula for water is . H. 2. O. Why Study Chemistry?. . Think about current issues in the news.. . . . . . . 2. Why Study Chemistry?. . Think about current issues in the news.. Energy sources. . . Percent Composition, . Empirical/ Molecular . Formula . Finishing Up Ch. 10. In 1811, Avogadro proposed a hypothesis:. Volumes of gases at the same temp and pressure have the same number of particles. Seating Chart. Warm Up 1/5-6. Imagine your boss wants you to count the number of Styrofoam packing peanuts in a large bag. Suppose you found the mass of 100 peanuts to be 5.5 g. How could you use this to find the number of peanuts in the bag?. Nivaldo. J. . Tro. Chapter 6. Chemical Composition. Dr. Sylvia Esjornson. Southwestern Oklahoma . State University . Weatherford, OK. How Much Sodium? . Sodium is an important dietary mineral . that . The Mole. Chemist’s counting number. amount. of a substance . 1 mole is equal to 6.022 x 10. 23. atoms or particles or molecules (Avogadro’s number). There are always 6.022 x 10. 23 . particles in . Nivaldo. J. . Tro. Chapter 6. Chemical Composition. Dr. Sylvia Esjornson. Southwestern Oklahoma . State University . Weatherford, OK. How Much Sodium? . Sodium is an important dietary mineral . that . Determining Molecular Formulas. Calculate the molecular formula of a compound whose molar mass is 60.0 g/mol and has an empirical formula of CH4N.. What you need:. Empirical Formula. Molar Mass. Calculate the molar mass of the empirical formula. Percent Composition. ~percent by mass of atoms present in a compound. = (mass of atom). . (total molar mass) x 100. water is . 88.81 . % Oxygen and . 11.19 . % Hydrogen. O- 16.00/18.016 x 100 = . 88.81 .