1. The Mole Mass & The Mole Ch. 10.1-10.2 CHM Hon.

2. How do you measure matter? Measure the amount by: –Counting –Mass –Volume

3. Measuring Matter Different forms of measurement relate –1 dozen apples = 12 apples –2.0 kg apples = 1 dozen apples –1 dozen apples = 0.2 bushel apples

4. Finding Mass from a Count What is the mass of 9 average- sized apples if 1 dozen apples has the mass of 2.0 kg? 15 kg

5. Finding Mass from a Count If 0.20 bushel is 1 dozen apples and a dozen apples has a mass of 2.0 kg, what is the mass of 0.5 bushel of apples? 5.0 kg

6. What is a mole? Remember: Matter is composed of atoms, molecules and ions Mole (mol) –6.02 x 10 23 representative particles of that substance –The SI Unit for measuring the amount of a substance

7. What is a mole? Avogadro’s number –The number of representative particles in a mole –6.02 x 10 23 –Avogadro (1776-1856): Italian scientist who helped clarify the difference between atoms and molecules

8. The Representative Particle Refers to the species present in a substance –Usually atoms, molecules or formula units –The representative particle of most elements is the atom –Sometimes the representative particle is a molecule ex) Molecular compounds (H 2 O) 7 elements normally exist as diatomic molecules –H 2, N 2, O 2, F 2, Cl 2, Br 2, I 2

9. The Representative Particle –A mole of any substance contains Avogadro’s number of representative particles (6.02 x 10 23 )

10. Converting Number of Particles to Moles 1 mol = 6.02 x 10 23 representative particles Conversion Factor:

11. Converting Number of Particles to Moles

12. 0.208 mol Mg

13. How many moles is 2.8 x 10 24 atoms of silicon? 4.65 mol Si

14. Converting Moles to Number of Atoms 1.40 x 10 25 atoms

15. amu Remember that atomic mass of an element (the mass of a single atom) is expressed in atomic mass units! –Relative values based on C-12 atom C-12 atom = Mass 12 amu H atom = Mass 1 amu

16. Atomic mass & Molar mass Molar mass = the mass of a mole of an element The Atomic mass of am element expressed in grams is the mass of a mole of the element –Carbon: molar mass = 12 g –Hydrogen: molar mass = 1 g –Sulfur: molar mass = ? –Mercury: molar mass = ? 32.1 g 200.6 g

17. Molar mass is the mass of 1 mol of atoms of any element!! Magnesium (Mg): 1 mol Mg  6.02 x 10 23 atoms Mg  Molar mass 24.3 g

18. Determining the Mass of a Mole of a Compound First step: determine the molecular formula –Ex) Sulfur trioxide: Second step: calculate the mass of the molecule –Add the atomic masses of the atoms

19. Finding the Molar Mass of a Compound 34.0 g

20. Finding the Molar Mass of a Compound Find the molar mass of PCl 3 106.5 g

21. Mole to Mole conversion 13.1 mol Ca

22. Determine the number of moles in 25.5 g Ag 0.236 mol Ag

23. Mass to Atoms Conversion

24. How many atoms are in 55.2 g Li? 4.79 x 10 24 atoms Li

25. Atoms to mass Conversion 0.366 g He

26. What is the mass in grams of 6.02x10 24 atoms Bi 2.09 x 10 3 g Bi

27. I am so confused!? Putting it into prospective… MASS  MOLES  REP. PARTICLES