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O.A # 1

O.A # 1. Molecular Formula. Page # 1. Cornell Notes- Video: The Mole 5 questions or main ideas Summary: 3-4 complete sentences. Molar Mass is the mass in grams of one mole of any pure substance. Ca = H = O = H 2 O = Ca(NO 3 ) 2 =. 40.1 g. 1.0 g. (from the periodic table).

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O.A # 1

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  1. O.A # 1 Molecular Formula

  2. Page # 1 Cornell Notes- Video: The Mole 5 questions or main ideas Summary: 3-4 complete sentences

  3. Molar Massis the mass in grams of one mole of any pure substance • Ca = • H = • O = • H2O = • Ca(NO3)2 = 40.1 g 1.0 g (from the periodic table) 16.0 g 18.0 g Mass of 1 Mole (1.0 x 2) + 16.0 164.1 g (14.0 x 2)+ (16.0 x 6)= 40.1 +

  4. O.A # 2 Mole

  5. Chapter 11 The Mole

  6. Page # 2 11.1 Measuring Matter The Mole Is the number of representative particles in exactly 12 g of pure Carbon-12 • How many eggs are in a dozen? • How many cans in a six pack of soda? • How many sheets of paper in a ream? • How many hours in a day? Is a quantity similar to………

  7. Conversions from mole to mass and mass to mole Practice Problems • Determine the mass in grams • of 3.57 mole of Al : Start with given amount. Multiply by the conversion factor 96.4 grams of Al 27.0 g 3.57 moles x ___________ = 1 mole Periodic table: mass of 1 mole = 27.0 g

  8. 2) Determine the mass in g in 42.6 mol Si? 28.1 g Si 42.6 mol Si x _________________ = 1 mole 1.20 x 103 grams of Si 3) What is the mass of 0.650 moles of CaCO3? 100.1 g 0.650 moles x __________ = 65.1 g CaCO3 1 mole 4) How many moles are contained with a 100.0 gram sample of NO2 1 mole 100.0 gram x ____________ = 2.174 moles NO2 46.0 g

  9. 5) Determine the number of moles in 25.5 g Ag ? 25.5 g Ag x _________________ = 1 mole 0.236 moles of Ag 107.9 g Ag 6) Determine the number of moles in 300.0 g S ? 300.0 g S x _________________ = 1 mole 9.346 moles of S 32.1 g S

  10. O.A #3 1. What mass (grams) is 0.04100 moles of BaF2 175.3 g 7.187 grams 0.04100 moles x ___________= 1 mole 2. How many moles in 4.5 g of CaSO3 4.5 g x 1 mole = 120.2 g 0.037 moles

  11. Page # 3 • Conversions among moles, grams, and representative particles • Representative Particle • A representative particle is any kind of particle such as atoms, molecules, or ions. • Avogadro’s number • 6.02 x 1023 particles in a mole. • 602 000 000 000 000 000 000 000

  12. Atoms Molecules Ions 1 Mole = 6.02 X 1023 1) How many atoms in 2.51 moles of zinc? 2.51 moles 6.02 X 1023 atoms 1.51 X 1024 atoms Zn x ______________ = 1 mole 2) How many moles in 5.75 X 1024 atoms of Al ? 1 mole 5.75X 1024atoms x ______________ = 9.55 Moles Al 6.02 X 1023 atoms 3) How many grams in 3.75 X 1024 Molecules of CO2? 44.0 g 3.75 X 1024 Molecules x ____________________ 6.02 X 1023 Molecules = 274 grams CO2

  13. O.A # 4(answer the question) A man died and his relatives found he had saved 20 barrels of pennies over his 92 years. Imagine you are one of those relatives and you want to find out how much money is in the barrels. It would take a really long time and a lot of effort to count each penny. Can you think of any way the value of the pennies could be found without counting each and every penny?

  14. O.A # 5 1. Calculate number of molecules in 0.7215moles of KClO4 2. How many grams in 5.52X 1023 atoms of Li ? 0.7215 moles X _________________ = 6.02 X 1023Molecules 1 mole 4.343 X 1023mc 5.52 X 1023 atoms x 6.9 g______ 6.02 X 1023 Atoms = 6.33 grams

  15. Quick Write • Explain in detail the steps needed to convert the mass (g) of a substance to the number of moles and to convert the number of moles to the number of atoms or molecules. (and vice versa)

  16. O.A # 6 Empirical Formula

  17. Page # 4 Empirical Formula of a Compound is the formula with the smallest ratio of the element Molecular Formula 1) H2O2 2)C6H12O6 Empirical Formula 1) HO 2) CH2O • Determine the empirical formula for a compound with a percentage composition of 54.1% calcium, 43.2% oxygen, and 2.70% hydrogen.

  18. Step 1: Find moles of each element. Use the percents by mass as grams and convert to number of moles Step 2: Divide moles of each element by least number of moles 1 mole • Ca: 54.1 g • O: 43.2 g • H: 2.70 g x ________= 1.35 moles = 1 1.35 40.1 g x ________= 1 mole 2.70 moles = 2 1.35 16.0 g 1 mole 2.70 moles = 2 x ________= 1.35 1.0 g CaO2H2 Ca(OH)2 Step 3: Multiply the number of moles in the ratio by The smallest number that will produce a ratio of whole numbers

  19. Solve the Practice Problems on pg. 333 #46-48 46. N2O3 47. Al2S3 48. C3H8

  20. O.A # 7Find E.F of 48.8% Cd, 20.8% C, 2.62% H and 27.8 % O. Use the percents by mass as grams CdC4H6O4 Cd(C2H3O2)2 1 mole Cd: 48.8 g C: 20.8 g H: 2.62 g O: 27.8 g x ________= 0.434 moles = 1 112.4 g 0.434 x ________= 1 mole 1.73 moles = 4 0.434 12.0 g 1 mole 2.62 moles = 6 x ________= 0.434 1.0 g 1 mole = 4 x ________= 1.74 moles 16.0 g 0.434

  21. Page # 5 Molecular Formula Specifies the actual number of atoms of each element in one molecule or formula unit of the substance Mathematical relationship between molecular and empirical formula. molecular formula = n (empirical formula) n = Given molar mass calculated mass of E.F

  22. Find the molecular formula for a compound with a percentage composition of 30.4% nitrogen and 69.6% oxygen. The molar mass of the compound is 92.0 g/mol. • N: 30.4 g • O: 69.6 g 1 mole x ________= 2.17 moles = 1 2.17 14.0 g 1 mole 4.35 moles = 2 x ________= 2.17 16.0 g NO2 Calculate mass of E.F using periodic table + = 46.0 g 14.0 gNitrogen 16.0 x 2 g Oxygen

  23. molecular formula = n (empirical formula) = 92.0 g n=Given molar mass calculated mass of E.F 46.0 g n= 2 Multiply the subscripts in the empirical formula by nto determine the actual subscripts in molecular formula 2 x (N1O2) = N2O4

  24. Solve the Practice Problems on pg. 335 #51-53 51. C6H6O2 52. C4H10 53. N2O2

  25. O.A # 8 Percent Composition

  26. Page # 6 Percent Composition of a Compound percent by mass of each element in a compound Al2O3 What is the percent composition of Aluminum Oxide? Step 1: Find mass of each element (periodic table) Al: 2x27.0 = 54.0 g O: 3x16.0 = 48.0 g + = 102.0 g Step 2: Divide mass of each element by total mass of compound x 100 Al: 54.0 g x 100 102.0 g O: 48.0 g x 100 = 102.0 g + = 100% Al2O3 = 53% Al = 47% O

  27. Solve the Practice Problems on • pg. 331 #42- 45 • 42) CaCl2 Ca:36%, Cl: 64% • 43) Na2SO4 Na: 32%, S: 23%, O: 45% • 44) H2SO3 S: 39%, H2S2O8 S: 33% • 45) H3PO4  H: 3%, P: 32%, O: 65%

  28. O.A # 9 Calculate percent composition of each element in Mg3(PO4)2 Mg: 3 x 24.3 = 72.9 g P: 2 x 31.0 = 62.0 g O: 8 x 16.0 = 128.0 g / 262.9 x 100 = 27.7 % / 262.9 x 100 = 23.6 % / 262.9 x 100 = 48.7 %

  29. O.A # 10 • 1. Calculate number of molecules in 2.50 moles of Ag(C2H3O2)2 • 2. How many grams in 5.65X 1021 atoms of C6H6? 6.02 X 1023Molecules 2.50 moles X _________________ = 1 mole 1.51 x 1024mc 5.65 x 1021 atoms x 78.0g______ 6.02 X 1023 Atoms = 0.732 grams

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