1. Starter S-89 1.List the elements and how many there are of each in Iron (III) oxide. 2.Multiply the number of each element by the average atomic mass of each. 3.Add these numbers together, this is called the molar mass.

2. Starter S-90 1.What is the molar mass of H 2 S? 2.How many moles of H 2 S would be found in 100 g? 3.How many formula units (particles) of H 2 S would be in 100g? Remember the lab from Tuesday

3. Chemical Quantities Chapter 10

4. 10.1 The Mole: A Measurement of Matter Chapter 10

5. Quantitative – yield a number value Most common methods count mass volume 10.1 The Mole

6. Words often mean a quantity pair – 2 dozen – 12 mole? 10.1 The Mole

7. Mole – means a specific number of particles This is called Avogadro’s Number The unit is used for atoms molecules (covalent compounds) formula units (ionic compounds) 10.1 The Mole

8. To convert numbers of particles to moles we need an equality This could also be Or Depending on what type of particle you are trying to convert 10.1 The Mole

9. The rest is just the conversion we have always done remember – the unit you have goes on the bottom of the fraction -the unit you are converting to goes on the top So to convert 2500 atom of C to moles 10.1 The Mole

10. Converting from moles to partciles follows the same process How many molecules of Carbon Dioxide are in 1.55 mol? 10.1 The Mole

11. Convert the following quantities to moles 1. 9,487,212 formula units of AgNO 3 2. 5.78x10 23 atoms of Nitrogen 3. 4.1x10 24 molecules of Carbon Monoxide 10.1 The Mole

12. Convert the following to the correct type of particle 1. 95 moles of CCl 4 2. 7.211x10 -3 moles of CuCO 3 3. 0.08 moles of Helium 10.1 The Mole

13. By definition, the atomic mass of an element in grams is the mass of one mole of the element. This is called the molar mass 10.1 The Mole

14. For a compound we must calculate the molar mass 1.Write down what type of atoms, and how many of each are present C 1 H 4 2. Multiply by the molar mass of each element 10.1 The Mole CH4CH4

15. For a compound we must calculate the molar mass 1.Write down what type of atoms, and how many of each are present C 1 x 12.0107g = H 4 x 1.00794g = 2. Multiply by the molar mass of each element 10.1 The Mole CH4CH4

16. For a compound we must calculate the molar mass 1.Write down what type of atoms, and how many of each are present C 1 x 12.0107g = 12.0107g H 4 x 1.00794g = 4.03176g 2.Multiply by the molar mass of each element 3.Add to get a total 10.1 The Mole CH4CH4

17. For a compound we must calculate the molar mass 1.Write down what type of atoms, and how many of each are present C 1 x 12.0107g = 12.0107g unit H 4 x 1.00794g = 4.03176g 2.Multiply by the molar mass of each element 3.Add to get a total 16.0425g CH 4 10.1 The Mole CH4CH4

18. Starter S-92 1.What is the molar mass of CO? 2.How many moles of CO would be found in 0.56 g? 3. How many molecules of CO would be found in 3.51 moles?

19. 10.2 Mole-Mass and Mole-Volume Chapter 10

20. 10.1 The Mole 10.2 Mole-Mass and Mole-Volume We don’t convert from particles to moles nearly as often as we do from moles to grams. The reason is that we usually measure the amount of a substance on the balance We need to know numbers of particles so that we can compare ratios of atom or compounds

21. 10.1 The Mole 10.2 Mole-Mass and Mole-Volume This is just another conversion problem The equality is Again, the quantity you have goes on the bottom, the quantity you want goes on top So if you have 9.5g of Carbon Value Molar Mass = 1 mole

22. 10.1 The Mole 10.2 Mole-Mass and Mole-Volume If you have 2.2 moles of Silver Nitrate convert to mass First we need to know the formula of Silver Nitrate Then the molar mass And finally we can convert

23. Try the following example: How many moles is 8.2g of Copper (II) Chloride Formula Molar mass Moles 10.1 The Mole 10.2 Mole-Mass and Mole-Volume

24. And another one: How many grams is 2.4 mol of Iron (III) Sulfate Formula Molar mass Moles 10.1 The Mole 10.2 Mole-Mass and Mole-Volume

25. In 1811, Amedeo Avogadro proposed Avagador’s Hypothesis – equal volumes of gases at the same temperature and pressure contain equal numbers of particles 10.1 The Mole 10.2 Mole-Mass and Mole-Volume

26. Standard Temperature and Pressure (STP) T – 0 o C or 273K P – 101.3 kPa, or 1 atm At STP the volume of one mole is 22.4L So the equality for conversion is 10.1 The Mole 10.2 Mole-Mass and Mole-Volume

27. To do these problems, the identity of the gas doesn’t really matter. If we have 15 L of Chlorine gas The number of moles would be 10.1 The Mole 10.2 Mole-Mass and Mole-Volume

28. If instead we calculate for a more complicated gas such as propane And we also have 15 L of propane gas The number of moles would be 10.1 The Mole 10.2 Mole-Mass and Mole-Volume

29. Starter S-96 1.What is the molar mass of Pb(SO 4 ) 2 ? 2.How many moles of Pb(SO 4 ) 2 would be found in 250 g? 3.How many moles of H 2 gas are found in 250 L?

30. 10.3 Percent Composition and Chemical Formulas Chapter 10

31. The relative amounts of the elements in a compound is called the percent composition The percent by mass of an element is the number of grams of the element divided by the mass in grams of the compound multiplied by 100% 10.1 The Mole 10.3 Percent Composition

32. Calculating the mass percent from a formula 1.Formula 2.Calculate the total mass of each element 3.Calculate the total mass of the compound 4.Calculate the percent by mass for each element 10.1 The Mole 10.3 Percent Composition

33. Calculate the mass percent 1.Formula 2.Mass of each element 3.Total mass 4.Mass Percent 10.1 The Mole 10.3 Percent Composition

34. Starter S-95 What is the percent by mass of the all the elements in Cu(NO 3 ) 2.

35. Empirical Formula – smallest whole number ratio of the elements in a compound The empirical formula can be calculated from the percent composition 10.1 The Mole 10.3 Percent Composition CompoundEmpirical Formula H2OH2OH2OH2O CH 3 COOHCH 2 O C 6 H 12 O 6 CH 2 O S8S8 S

36. To calculate the empirical formula 1.List the elements and their percent compositions 2.Convert the percent compositions to moles 3.Calculate the mole ratio (divide by the smallest number of moles) 4.Smallest Whole Number ratio 5.Write the Formula 10.1 The Mole 10.3 Percent Composition

37. To calculate the empirical formula 1.Elements 2.Convert to Moles 3.Mole ratio 4.Whole Number ratio 5.Write the Formula 10.1 The Mole 10.3 Percent Composition

38. Starter S-97 What is the empirical formula if Lead is 59.7% Hydrogen is 2.9% Arsenic is 21.6% Oxygen is 18.4%

39. The molecular formula can be calculated from the empirical formula and the molar mass 10.1 The Mole 10.3 Percent Composition Comparison of Empirical and Molecular Formulas FormulaClassificationMolar Mass CHEmpirical13 C2H2C2H2 Molecular26 (2x13) C6H6C6H6 Molecular78 (6x13) CH 2 OEmpirical30 C2H4O2C2H4O2 Molecular60 (2x30) C 6 H 12 O 6 Molecular180 (6x30)

40. Steps in calculations (if mass=60.0g) 1.Determine the empirical formula 2.Calculate the mass of the empirical formula 3.Divide the actual molar mass by this number 4. Multiply the empirical formula 10.1 The Mole 10.3 Percent Composition

41. Starter S-99 What is the empirical formula if Silver – 63.5% Nitrogen – 8.2 % Oxygen – 28.2% If the formula mass is 170g, what is the formula of this compound?

42. Practice Problem 1 A.How many moles of AgNO 3 are found in 125 g? B.How many grams of AgNO 3 are found in 2.99 moles?

43. Practice Problem 2 A.How many molecules are found in 19.5 moles of CH 2 O? B.How many grams of CH 2 O are found in 1.8x10 24 molecules?

44. Practice Problem 3 A.What is the empirical formula of the following compound Na-43.4% C – 11.3% O – 45.3%

45. Practice Problem 4 A.What is the empirical formula C – 3.2g H – 0.53g O – 4.3 g B.If the molar mass is 330, what is the molecular formula?

46. Starter S-102 Test Day Great and Glorious Test Day Yahoo Yipee Yah

47. Starter S-105 What is the empirical formula if Carbon – 49.5% Hydrogen – 5.2% Nitrogen – 28.9% Oxygen – 16.5% What if the molecular formula, if the molar mass is 194g?