PPT-Empirical and Molecular Formulas

Chemistry GT 32015 Drill Calculate the percent composition of Na 2 SO 4 HW Molecular Formula WS pg 4 MM 14205 g mol 3237 Na 2258 S 4505 O Chem Joke of the Day The photon checked into a hotel What did it say when the bellhop asked for its bag. Week 22 Chemistry. Warm Up: . 3. Minutes. A certain bag of M&M’s has 8 blue candies, 7 red candies, 4 green candies, and 6 yellow candies. What percentage of the bag is blue M&M’s? . Record your Learning . . vs. . Empirical Formula. Different compounds can have the . same. empirical formula. but . different. molecular formulas. .. Empirical . Formula is a . reduced. . form of Molecular formula . Molecular Formula and Empirical Formula. 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. 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. 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. 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 . 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.. Due at end of Period. The compound . benzamide. has the following percent composition. What is the empirical formula? . C . = 69.40 % H= 5.825 % O = 13.21 % N= 11.57 % . 2. A . component of protein called serine has an approximate . Empirical Formula . = . consists of the symbols for the elements combined in a compound, with subscripts . showing the smallest whole number ratio. Molar mass. = . the mass in grams of 1 mole of a substance. Lowest whole # ratio . H. 2. O. 2. (hydrogen peroxide) is it a empirical Formula?. No, you can reduce it to HO . . H. 2. O. 2 . is the molecular formula. Molecular formula shows the way the molecule is actually found in nature.. 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. Breaks down the amount of an element in a compound by percentage. Total mass of element / total mass of compound. Result will always be a decimal. Multiply by 100 to get the final percentage. 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 .