The Mole Mass Formulas Dr Ron Rusay Chem

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The Mole, Mass & Formulas Dr. Ron Rusay Chem 106 Spring 2004 © Copyright

The Mole, Mass & Formulas Dr. Ron Rusay Chem 106 Spring 2004 © Copyright 2004 R. J. Rusay

The Mole http: //dbhs. wvusd. k 12. ca. us/Mole. html • • Definition: The

The Mole http: //dbhs. wvusd. k 12. ca. us/Mole. html • • Definition: The number of carbon atoms in exactly 12 grams of pure 12 C. The number equals 6. 02 10 23 atoms. 1 mole = 6. 02 10 23 units 6. 02 10 23 “units” of anything: atoms, people, stars, $s, etc. = 1 mole There about 6. 2 billion people in the world. How many moles of people are there?

Avogadro’s Number http: //www. carlton. paschools. pa. sk. ca/chemical/molemass/avogadro. htm Avogadro’s number equals 1

Avogadro’s Number http: //www. carlton. paschools. pa. sk. ca/chemical/molemass/avogadro. htm Avogadro’s number equals 1 mole …. which equals 6. 022 23 10 “units” How many molecules are there in 0. 5 moles of oxygen? What do you get if you divide an avocado into 6. 02 x 10 guaca-mole! 23 pieces?

Calculate the number of atoms of silicon in 0. 367 moles of silicon. a)

Calculate the number of atoms of silicon in 0. 367 moles of silicon. a) 6. 10 x 10 -25 atoms Si b) 2. 21 x 10 23 atoms Si c) 2. 21 atoms Si d)1. 64 x 10 24 atoms Si What do you need ? Avogadro’s Number 1 mole = 6. 02 x 10 23 atoms 0. 367 mol x 6. 02 x 10 23 atoms / 1 mol = 2. 21 x 10 23 atoms Si

Counting by Weighing 12 red marbles @ 7 g each = 84 g 12

Counting by Weighing 12 red marbles @ 7 g each = 84 g 12 yellow marbles @4 g each=48 g 55. 85 g Fe = 6. 022 x 1023 atoms Fe 32. 07 g S = 6. 022 x 1023 atoms S Consult the Periodic Table

Relative Masses of 1 Mole Ca. CO 3 Name? 100. 09 g Oxygen 32.

Relative Masses of 1 Mole Ca. CO 3 Name? 100. 09 g Oxygen 32. 00 g Copper 63. 55 g Water 18. 02 g What is the volume of 1 mole of water? 1 mole of a gas equals 22. 4 Liters. (A balloon diameter of 35 cm. )

Atomic and Molecular Weights Mass Measurements • 1 H weighs 1. 6735 x 10

Atomic and Molecular Weights Mass Measurements • 1 H weighs 1. 6735 x 10 -24 g and 16 O 2. 6560 x 10 -23 g. • DEFINITION: mass of 12 C = exactly 12 amu. • Using atomic mass units: • 1 amu = 1. 66054 x 10 -24 g • 1 g = 6. 02214 x 1023 amu

Atomic and Molecular Weights • Formula Weight a. k. a. Molecular Weight • Formula

Atomic and Molecular Weights • Formula Weight a. k. a. Molecular Weight • Formula weights (FW): sum of Atomic Weights (AW) for atoms in formula. • FW (H 2 SO 4) = 2 AW(H) + AW(S) + 4 AW(O) • = 2(1. 0 amu) + (32. 0 amu) + 4(16. 0) • = 98. 0 amu

Atomic and Molecular Weights • Molecular weight (MW) is the weight of the molecular

Atomic and Molecular Weights • Molecular weight (MW) is the weight of the molecular formula in amu. • MW of sugar (C 6 H 12 O 6 ) = ? • MW = 6(12. 0 amu) + 12(1. 0 amu) + 6(16. 0 amu) • = 180 amu

Molar Mass • A substance’s molar mass is the mass in grams of one

Molar Mass • A substance’s molar mass is the mass in grams of one mole of the element or compound. (Equals the formula weight: atomic or molecular weight in grams) Molar Mass CO 2 = ? C = 12. 01 grams per mole (g/mol) O = 16. 00 grams per mole (g/mol) CO 2 = 44. 01 grams per mole (g/mol) 12. 01 + 2(16. 00) = 44. 01

Calculate the molar mass of potassium phosphate. a) 134 g/mol b) 86. 07 g/mol

Calculate the molar mass of potassium phosphate. a) 134 g/mol b) 86. 07 g/mol c) 134. 07 g/mol d) 212. 27 g/mol What do you need ? 1) Formula of potassium phosphate: K 3 PO 4 2) Atomic Weights (molar mass) K = 39. 10, P = 30. 97, O = 16. 00 3(39. 10) + 30. 97 + 4(16. 00) = 212. 27 g/mol

Calculate the mass in grams of 4. 00 moles of sulfur. a) 128 g

Calculate the mass in grams of 4. 00 moles of sulfur. a) 128 g b) 128. 3 g c) 12. 5 g d) 0. 125 g What do you need ? Atomic Weight sulfur (S) = 32. 07 (molar mass) = 32. 07 g/mol 4 mol sulfur x 32. 07 g/mol sulfur = 128. 3 g

Percent Composition • Mass percent of an element: • For iron in (Fe 2

Percent Composition • Mass percent of an element: • For iron in (Fe 2 O 3), iron (III) oxide = ? Which iron ore would you buy: one high in Fe 2 O 3 or one high in Fe. O, Iron (II) oxide? 55. 84 / 71. 84 x 100 = 77. 7%

Calculate the percentage composition for all the elements in nicotine, C 10 H 14

Calculate the percentage composition for all the elements in nicotine, C 10 H 14 N 2. a) 64. 14% C, 14. 04% H, 21. 82% N b) 74. 017 % C, 8. 714 % H, 17. 27 % N c) 74. 02 % C, 8. 71 % H, 17. 27 % N d) 44. 43 % C, 3. 74 % H, 51. 83 % N What do you need ? Molar mass C 10 H 14 N 2 C = 12. 01, H = 1. 01, N = 14. 01 10(12. 01) + 14(1. 01) + 2(14. 01) = 162. 26 g/mol 120. 1 g/mol 14. 14 g/mol 28. 02 g/mol 120. 1/ 162. 26 14. 14 / 162. 26 28. 02 / 162. 26 x 100 = 74. 02% x 100 = 8. 71% x 100 = 17. 27%

Formulas: Dalton’s Law • Dalton’s law of multiple proportions: When two elements form different

Formulas: Dalton’s Law • Dalton’s law of multiple proportions: When two elements form different compounds, the mass ratio of the elements in one compound is related to the mass ratio in the other by a small whole number.

Formulas: Multiple Proportions

Formulas: Multiple Proportions

Formulas & Multiple Proportions Components of acid rain, SO 2(g) and SO 3(g) •

Formulas & Multiple Proportions Components of acid rain, SO 2(g) and SO 3(g) • Compound A contains: 1. 000 g Sulfur & 1. 500 g Oxygen • Compound B contains: 1. 000 g Sulfur & 1. 000 g Oxygen • Mass ratio A: 1 to 1. 5; Mass ratio B: 1 to 1 • MUST adjust for atomic mass differences: AW sulfur is 2 x the AW oxygen; therefore the oxygen ratios are 2 x sulfur. • S 1 O 3 and S 1 O 2 respectively

Formulas & Molecular Representations molecular formula = C 6 H 6 Benzene empirical formula

Formulas & Molecular Representations molecular formula = C 6 H 6 Benzene empirical formula = CH = C 6/6 H 6/6 molecular formula = (empirical formula)n [n = integer] (CH)6 • Other representations: Lewis Dot formulas, structural formulas, 2 -D, 3 -D

Formulas & Molecular Representations

Formulas & Molecular Representations

Structural Representations of Quinine http: //ep. llnl. gov/msds/pdb/quinine. pdb

Structural Representations of Quinine http: //ep. llnl. gov/msds/pdb/quinine. pdb

Molar Comparisons of Analgesics Moles : Doses (mmol/dose) Which analgesic has the most biologically

Molar Comparisons of Analgesics Moles : Doses (mmol/dose) Which analgesic has the most biologically active ingredient based on millimoles per dose (mmol/dose)? 5. 0 g of each would produce the following number of doses: Aspirin Ibuprofen Naproxen Sodium Acetaminophen Formula Doses C 9 H 8 O 4 15. 4 C 13 H 18 O 2 25 C 14 H 13 O 3 Na 22. 7 C 8 H 9 NO 2 5 mmol/dose • What is the road map for a dimensional solution? • Rank the analgesics in biological activity from highest to lowest.