1. The Mole

2. What is a mole? A conversion factor we use in chemistry to make it easier to talk about a very large amount of particles of elements or compounds 1 dozen bagels = 12 bagels 1 mole bagels = 6.02 x 10 23 bagels

3. Avogadro’s Number Avogadro’s # = 6.02 x 10 23 units How does this number relate to a mole? 1 mole = 6.02 x 10 23 units *Units can be anything but in chemistry these units are referred to as: Particles Atoms Molecules Formula Units

4. How big is 6.02 x 10 23 ? Astronomers estimate that there is a mole of stars in the Universe. One mole of high school textbooks would cover the USA to a depth of about 300 Km. One mole of marshmallows would cover the USA to a depth of 105 000 Km. One mole of moles placed to head to tail would stretch 11 million light years and weigh 9/10 as much of the moon. One mole of pennies would make at least seven stacks that would reach the moon. One mole of watermelon seeds would be found inside a melon slightly larger than the moon.

5. Examples 1 mole Fe = 6.02 x 10 23 atoms Fe 1 mole C 12 H 22 O 11 = 6.02 x 10 23 molecules C 12 H 22 O 11 1 mole Al = 6.02 x 10 23 atoms Al 1 mole BeF 2 = 6.02 x 10 23 formula units BeF 2

6. Moles Particles Conversion Remember… 1 mol = 6.02 x 10 23 units Units in chemistry are atoms, molecules, formula units, particles

7. Moles To Particles How many atoms of carbon make up 6.80 moles of carbon? 6.80 mol C 6.02 x 10 23 atoms C 4.09 x 10 24 atoms C 1 mol C

8. Moles To Particles How many formula units of potassium phosphate make up 1.3 moles? 1.3 mol K 3 PO 4 6.02 x 10 23 f.u. K 3 PO 4 7.8 x 10 23 f.u. K 3 PO 4 1 mol K 3 PO 4

9. Moles To Particles 2 moles of carbon dioxide = ? molecules 2 mol CO 2 6.02 x 10 23 molecules CO 2 1 x 10 24 molecules CO 2 1 mol CO 2

10. Particles To Moles 5.60 x 10 25 atoms Cu 1 mol Cu 93.0 mol Cu 6.02 x 10 23 atoms Cu How many moles make up 5.60 x 10 25 atoms of copper?

11. Particles To Moles How many moles make up 6.3 x 10 23 formula units of ammonium nitride? 6.3 x 10 25 f.u. (NH 4 ) 3 N 1 mol (NH 4 ) 3 N 1.0 x 10 2 mol (NH 4 ) 3 N 6.02 x 10 23 f.u. (NH 4 ) 3 N

12. Particles To Moles 25 molecules of carbon tetrahydride = ? moles 25 molecules CH 4 1 mol CH 4 4.2 x 10 -23 mol CH 4 6.02 x 10 23 molecules CH 4

14. How is the mole measured in the lab? It is impossible to count up individual particles of chemicals in the lab because of their small size We must find another way to measure 6.02 x 10 23 particles of a substance

15. How does mass relate to the mole? What does an amu (atomic mass unit) measure? 1 amu = 1.66053886 × 10 -27 kilograms A relative scale used to measure the mass of single elements or compounds

16. Learning the termonology… Atomic Mass Atomic Mass - measures the mass of a single atom in amu’s Example: 1 atom Fe = 55.85 amu *Always go to the hundredths place when taking measurements from the periodic table

17. Formula Mass Formula Mass - measures the mass of a single formula unit (ionic compound) in amu’s Example: 1 formula unit BeF 2 = 1Be9.01 amu + 2F2(19.00 amu) = 47.01 amu

18. Molecular Mass Molecular Mass - measures the mass of a single molecule in amu’s Example: 1 molecule C 12 H 22 O 11 = 12 C atoms 12(12.01 amu) + 22 H atoms22(1.01 amu) + 11 O atoms11(16.00 amu) = 342.34 amu

19. Molar Mass The mass of 1 mole of any substance in grams Example: 1 atom Fe = 55.85 amu 1 mole (6.02 x 10 23 atoms) Fe = 55.85 g 1 molecule C 12 H 22 O 11 = 342.34 amu 1 mole (6.02 x 10 23 molecules) C 12 H 22 O 11 = 342.34 g

20. What is a representative particle? The smallest particle that represents the true identity of the entire substance without altering it’s characteristics or properties Example: What is the representative particle of 52 Al atoms?

21. Answer: 1 atom Al Example: What is the representative particle of 1 molecule of BeF 2 ?

22. Answer: 1 molecule BeF 2 1 atom of Be or 1 atom of F would not truly represent the properties and characteristics of BeF 2

23. Moles Grams Conversion Remember… molar mass can be used as a conversion for any type of particle 12.01 grams C = 1 mole C 58.44 grams of NaCl = 1 mole NaCl 44.01 grams of CO 2 = 1 mole CO 2

24. Moles To Grams How many grams is 4.672 mol barium chloride? 1 mol BaCl 2 = 208.23 g BaCl 2 4.672 mol BaCl 2 208.23 g BaCl 2 972.9 g BaCl 2 1 mol BaCl 2

25. Grams To Moles.0025 g disulfur trioxide = ? mol 1 mol S 2 O 3 = 112.14 g S 2 O 3.0025 g S 2 O 3 1 mol S 2 O 3 2.2 x 10 -5 mol S 2 O 3 112.14 g S 2 O 3

27. Grams Particles Converting This is a 2-step process. You must ALWAYS go through the mole first.

28. Grams To Particles How many atoms of platinum are needed to obtain 15.00 g? 195.08 g Pt = 1 mol Pt 1 mol Pt = 6.02 x 10 23 atoms Pt 15.00 g Pt1 mol Pt6.02 x 10 23 atoms Pt4.629x 10 22 atoms Pt 195.08 g Pt1 mol Pt

29. Particles To Grams What is the mass of 2.77 x 10 13 molecules of oxygen? 32.00 g O 2 = 1 mol O 2 1 mol O 2 = 6.02 x 10 23 molecules O 2 2.77 x 10 13 molecules O 2 1 mol O 2 32.00 g O 2 1.47 x 10 -9 g O 2 6.02 x 10 23 molecules O 2 1 mol O 2

30. Liters Moles Conversion Liters (L) are a volume unit of measurement STP = standard temperature and pressure conditions (0°C and 1 atm) This conversion only may be used when: – At STP conditions – Working with gases 1 mole = 22.4 L of gas @ STP

31. Liters To Moles How many moles of chlorine gas @ STP take up 4.9 L of space? 4.9 L Cl 2 1 mol Cl 2.22 mol Cl 2 22.4 L Cl 2

32. Mole To Liters How much space does.0359 moles of carbon monoxide gas take up @ STP?.0359 mol CO 22.4 L CO.804 L CO 1 mol CO

33. Liters Particles Converting This is a 2-step process. You must ALWAYS go through the mole first.

34. Liters To Particles How many molecules of iodine gas take up 3.56 L of space @ STP? 1 mole = 22.4 L of gas @ STP 1 mole = 6.02 x 10 23 particles 3.56 L I 2 1 mol I 2 6.02 x 10 23 molecules I 2 9.57 x 10 22 molecules I 2 22.4 L I 2 1 mol I 2

35. Particles To Liters How much space does 3.5 x 10 22 molecules of nitrogen dioxide gas take up @ STP? 1 mole = 22.4 L of gas @ STP 1 mole = 6.02 x 10 23 particles 3.5 x 10 22 molecules NO 2 1 mol NO 2 22.4 L NO 2 1.3 L NO 2 6.02 x 10 23 molecules NO 2 1 mol NO 2

36. Liters Grams Converting This is a 2-step process. You must ALWAYS go through the mole first.

37. Liters To Grams What is the mass of.57 L of hydrogen gas @ STP? 1 mole = 22.4 L of gas @ STP 1 mole = 2.02 g H 2.57 L H 2 1 mol H 2 2.02 g H 2.051 g H 2 22.4 L H 2 1 mol H 2

38. Grams To Liters How much space does 5 x 10 5 g of water vapor take up @ STP? 1 mole = 22.4 L of gas @ STP 1 mole = 18.02 g H 2 O 5 x 10 5 g H 2 O1 mol H 2 O22.4 L H 2 O6 x 10 5 L H 2 O 18.02 g H 2 O1 mol H 2 O