2. 1 Chapter 12 Mole Objectives Relate Avogadro’s number to a mole of a substance Calculate the mass of a mole of any substance Convert among mass, volume and number of particles

3. 2 You may count your CD’s in numbers, soda cans in six packs or cases of 12, apples by the dozens, or you weigh yourself on a scale in lbs or kilograms, measure volume of milk in liters or gallons etc. How do you measure quantities?

4. 3 The Mole: A measurement of matter SI Unit This sand sculpture contains millions of grains of sand How big is a mole? 6.02 x 10 23 particles One mole of sand grains would cover the area of Los Angeles to a height of 600 meters (about 0.35 miles)

5. 4 How big is a mole? 6.02 x 10 23 representative particles = Avogadro’s number Amadeo Avogadro 1776 - 1856 Representative particle refers to the species present: usually atoms, molecules or formula units Most elements are composed of atoms, but 7 gases exist as diatomic molecules: Hydrogen H 2, Nitrogen N 2, Oxygen O 2, Fluorine F 2, Chlorine Cl 2, Bromine Br 2, Iodine I 2 (start at 7, make a 7)

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7. 6 1 mole = 6.02 x 10 23 representative particles Why specifically Avogadro’s number? Why specifically Avogadro’s number? Example Sodium atom (Na): 11 protons 12 neutrons (11 electrons) 23 u (atomic mass units) If we take exactly 6.02 x 10 23 sodium atoms of this isotope, it’s mass will be 23.0 g 23 u  1 mole  23 g What is the mass of 1 mole of Carbon-12 atoms (6 protons, 6 neutrons)? 12 g (molar mass)

8. 7 The mass of a mole of a molecular compound = 32.1 u + 3x (16.0 u) = 80.1 u 80.1 u  1 mole  80.1 g molar mass What is the molar mass of SO 2 ? 64.1g

9. 8 The mass of a mole of an ionic compound 23.0 u + 35.5 u = 58.5 u 58.5 u  1 mole  58.5 g molar mass Cl - Na + smallest whole number ratio NaCl What is the molar mass of Na 2 O? 62.0g

10. 9 To calculate the molar mass of any compound, just add the atomic mass (see periodic table) of each atom in the formula Keyterms so far Mole Avogadro’s number Representative Particle Molar mass __1 Mole__can be used as a Molar mass conversion factor

11. 10 Chemical Quantities A chemist may have to find out how many grams of the elements hydrogen and nitrogen must be reacted to make 200 g of the fertilizer ammonia (NH 3 ) A chemist uses the balanced equation and the Mole as a measurement of matter

12. 11 The Molar Mass of any substance is the mass in grams of one mole of the substance What is the molar mass of N 2 O 3 ? 1 mol N 2 O 3 = 76.0g How many grams are in 9.45 mol of N 2 O 3 ? Knownunknownconversion 9.45 mol? g ? 9.45 mol N 2 O 3 x 76.0g N 2 O 3 = 718g N 2 O 3 1.00 mol N 2 O 3

13. 12 Calculating around mole Conversion factors you typically use: 1 mole. 6.02 x 10 23 particles Your conversion factor contains the old and the new unit!!! Always Start with what you know and use your conversion factor so that the old unit cancels out until you reach the desired unit and for gases 1 mole 22.4L 1 mole =1 mole molar mass xy grams

14. 13 Mole Map Use the following conversion factors to convert between mole and mass, volume or # of particles

15. 14 Volume of gas (STP) 22.4L 1.00 mol 22.4L molar mass 1.00 mol 6.02 x10 23 p. 1.00 mol molar mass Particles 1.00 mol 6.02 x10 23 p. Mass Mole

16. 15 What is….. ? 1 (800) 602 – 1023 Avogadro’s number What is Avogadro's favorite kind of music? Rock 'N' Mole What is the chemists’ favorite food? Avogadros and Guacamole

17. 16 Avogadro’s Favored Currency The Mollar m

18. 17 How many moles are 23.7g of water? Knownunknownconversion Calculation

19. 18 Calculated the mass (grams) of 4.8 mol of C 2 H 8. Knownunknownconversion Calculation

20. 19 65.5g of C 3 H 6 O make how many moles? Knownunknownconversion Calculation

21. 20 Calculated the mass (grams) of 75 mol of hydrogen gas (H 2 ) Knownunknownconversion Calculation

22. 21 One teapoon of salt contains 7.34g NaCl. Convert this number to moles of NaCl. Knownunknownconversion Calculation

23. 22 Prepare for lab: 1) One teapoon of water contains 14.7g H 2 O. Convert this mass to moles of H 2 O. Knownunknownconversion Calculation

24. 23 2) How many water molecules are in 0.8 mol of H 2 O? Knownunknownconversion Calculation

25. 24 3) How many atoms are in 4.8 x10 23 H 2 O molecules? a)How many atoms are in one molecule H 2 O? b) Multiply your answer from a) with 1.57 x10 23