1. The Molar Mass Lesson 2

2. Molar Mass The atomic mass of an element is the relative mass of the element. It is measured in grams and found on the periodic table. The molar mass is the mass of one mole of particles and the unit is grams/mole. Let’s see where to find it on the periodic table!

3. Formula Molar Mass (g/mol) 1 H 1.0 g/mole 4.0 g/mole He CO 2 more than one atom ???

4. To find the Molar Mass Consider the molar mass of all the atoms involved: CO 2 1 ( 12.0 )+2 (16.0) = 44.0 g/mole.

5. Formula Molar Mass (g/mol) 1 H 1.0 g/mole 4.0 g/mole He CO 2 44.0 g/mole Fe 2 O 3

6. To find the molar mass: Fe 2 O 3 2 (55.8)+ 3 (16.0) = 159.6 g/moles.

7. TRY: Find the molar mass of: Ni 2 (CO 3 ) 3

8. Formula Molar Mass (g/mol) 1 H 1.0 g/mole 4.0 g/mole He CO 2 44.0 g/mole Fe 2 O 3 159.6 g/mole Al(NO 3 ) 3. 5H 2 O Ni 2 (CO 3 ) 3 297.4 g/mole

9. Al(NO 3 ) 3. 5H 2 O 1 ( 27.0) + 3 (14.0) + 9 (16.0) + 10 (1.0) + 5 (16.0) Al N O H O 303.0 g/mole

10. TRY: Find the molar mass of Lead(II) iodate

11. Conversion factors are back!

12. Particles MolesGrams 1.00 mole = 6.02 x 10 23 particles Molar Mass From Periodic Table ? g / mole The molar mass is a new conversion factor that can convert between grams and moles Avogadro’s number is another conversion factor that can convert between moles and particles

13. Convert 56.6 grams of C to moles. Don’t forget sig figs! 3 sig figs = 4.72 moles x 1 mole 12.0 g 56.6 g

14. Convert 6.9 moles of PbO 2 into grams = 1.7 x 10 3 g 1 mole x 239.2 g 6.9 moles

15. Two-Step Mole Calculations

16. Convert 2.00 g CH 4 into molecules grams moles molecules = 7.51 x 10 22 molecules x 6.02 x 10 23 molecules 1 mole 16.04 g x 1 mole 2.00 g CH 4

17. Convert 9.56 x 10 26 molecules Cl 2 into grams. moleculesmolesgrams = 1.13 x 10 5 g x 71.0 g 6.02 x 10 23 molec x 1 mole9.56x10 26 molec Cl 2 1 mole

18. Try: Convert 692.5 grams Na 2 CO 3 into molecules. g moles molecules

19. Try: Convert 8.66 x 10 24 particles of CaCl 2 into grams particles moles g Happy Mole day to You

20. Homework page 80 page 84 #6 a, c, e, g, i, k, p #15 b, c, g #7 a, c Page 82 #8 b, f, I #9 a, h, g