1. Moles of Compounds

2. A properly written compound shows the ratio of atoms in the compound. For example, sodium carbonate (Na 2 CO 3 ) shows that for every 1 compound there are 2 atoms of Na, 1 atom of C, and 3 atoms of O.

3. This also works with the mole. For 1 mole of the compound, there are 2 moles of Na, 1 mole of C, and 3 moles of O. This information allows us to calculate the molar mass of the entire compound, often called the formula mass.

4. 2 mols Na22.9897 g = 45.9794 g Na 1 mol 1 mol C12.0107 g = 12.0107 g C 1 mol 3 mols O15.9994 g = 47.9982 g O 1 mol The total molar mass of Na 2 CO 3 is 105.9883 g.

5. Once it is known that 1 mol of Na 2 CO 3 = 105.9883 g, conversion factors can be made of this information: These conversion factors can then be used in other calculations. 105.9883 g Na 2 CO 3 or 1 mol 105.9883 g Na 2 CO 3

6. What is the molar mass for potassium oxide (K 2 O)?

7. K 2 O = 2 x K + 1 x O

8. What is the molar mass for potassium oxide (K 2 O)? K 2 O = 2 x K + 1 x O K 2 O = (2 x 39.0983 g) + (15.9994 g)

9. What is the molar mass for potassium oxide (K 2 O)? K 2 O = 2 x K + 1 x O K 2 O = (2 x 39.0983 g) + (15.9994 g) K 2 O = 78.1966 g + 15.9994 g = 94.1960 g

10. If you have 560.0 grams of K 2 O, how many moles do you have?

11. 560.0 g K 2 O =

12. If you have 560 grams of K 2 O, how many moles do you have? 560.0 g K 2 O1 mol = 94.196 g

13. If you have 560.0 grams of K 2 O, how many moles do you have? 560.0 g K 2 O1 mol = 5.945 mol K 2 O 94.196 g

14. If you have 3.4 moles of K 2 O, how many grams do you have?

15. 3.4 mols K 2 O =

16. If you have 3.4 moles of K 2 O, how many grams do you have? 3.4 mols K 2 O94.2 g = 1 mol

17. If you have 3.4 moles of K 2 O, how many grams do you have? 3.4 mols K 2 O94.2 g = 320 g K 2 O 1 mol

18. If you have 54.3 grams of cobalt(II) chloride, how many formula units (compounds) and how many atoms is this? 54.3 g CoCl 2 =

19. If you have 54.3 grams of cobalt(II) chloride, how many formula units (compounds) and how many atoms is this? 54.3 g CoCl 2 = 129.8 g 58.93g + (2 x 35.45 g)

20. If you have 54.3 grams of cobalt(II) chloride, how many formula units (compounds) and how many atoms is this? 54.3 g CoCl 2 1 mol CoCl 2 = 129.8 g

21. If you have 54.3 grams of cobalt(II) chloride, how many formula units (compounds) and how many atoms is this? 54.3 g CoCl 2 1 mol CoCl 2 = 129.8 g1 mol CoCl 2

22. If you have 54.3 grams of cobalt(II) chloride, how many formula units (compounds) and how many atoms is this? 54.3 g CoCl 2 1 mol CoCl 2 6.022 x 10 23 formula units = 129.8 g1 mol CoCl 2

23. If you have 54.3 grams of cobalt(II) chloride, how many formula units (compounds) and how many atoms is this? 54.3 g CoCl 2 1 mol CoCl 2 6.022 x 10 23 formula units = 2.52 x 10 23 formula units 129.8 g1 mol CoCl 2

24. If you have 54.3 grams of cobalt(II) chloride, how many formula units (compounds) and how many atoms is this? 2.52 x 10 23 formula units CoCl 2

25. If you have 54.3 grams of cobalt(II) chloride, how many formula units (compounds) and how many atoms is this? 2.52 x 10 23 formula units CoCl 2 1 formula unit CoCl 2

26. If you have 54.3 grams of cobalt(II) chloride, how many formula units (compounds) and how many atoms is this? 2.52 x 10 23 formula units CoCl 2 3 atoms 1 formula unit CoCl 2

27. If you have 54.3 grams of cobalt(II) chloride, how many formula units (compounds) and how many atoms is this? 2.52 x 10 23 formula units CoCl 2 3 atoms = 7.56 x 10 23 atoms 1 formula unit CoCl 2