1. Lecture 5.3 – Moles to Moles and Grams to Grams

2. Today’s Learning Targets
LT 4.5 – I can convert from moles of one compound to moles of another compound using the mole ratio from a balanced chemical reaction.
LT 4.6 – I can convert from grams of one compound to grams of another compound.

3. Focus for Last Unit Molarity of Substance A Volume of Substance B
Moles of A
Moles of B
Grams of Substance B
Grams of Substance A
Atoms of Substance A
Atoms of Substance B

4. Molarity of Substance A Molarity of Substance B
Moles of A
Moles of B
Grams of Substance B
Grams of Substance A
Atoms of Substance A
Atoms of Substance B

5. What is a mole ratio?

6. I. The Importance of Balanced Reactions
We have been balancing chemical reactions so that we can use them in these calculations.
Without a balanced reaction, we CANNOT do the calculations that we use in stoichiometry.

7. II. Mole Ratios
The coefficients in a balanced equation represent the moles of each substance.
These coefficients can be used as a conversion factor known as a mole ratio
Mole ratios allow for us to convert between moles of two substances

8. 3Mg + N2  Mg3N2 3 moles Moles Mg 1 moles Moles Mg3N2
Mole Ratio for Mg to Mg3N2
3Mg + N2  Mg3N2
3 moles
Moles Mg
1 moles
Moles Mg3N2

9. Class Example For the following reaction: NaCl + CaO  Na2O + CaCl2
Write the mole ratio of NaCl to CaCl2?

10. _____Fe + ____CuSO4  ____Cu + ___Fe2(SO4)3
Table Talk
For the following reaction:
_____Fe + ____CuSO4  ____Cu + ___Fe2(SO4)3
Write the mole ratio of Fe to Cu?

11. How do we convert between moles of two substances?

12. I. Mole to Mole Conversion Factor
Our conversion factor for converting moles to moles is:
Mole Ratio

13. Class Example
For the following chemical reaction of the airbag in our car:
NaN3 (s)  Na (s) + N2 (g)
If you have 6 moles of NaN3, how many moles of Na will this reaction produce?

14. Table Talk For the following reaction: N2O5 + H2O  NH4OH + O2
If you have 5 moles of N2O5 determine the number of moles of NH4OH do you get?

15. Molarity of Substance A Molarity of Substance B
Moles of A
Moles of B
Grams of Substance B
Grams of Substance A
Have students label the conversion factor above each arrow, then have them label the entire set
Atoms of Substance A
Atoms of Substance B

16. How do we convert grams of one substance to grams of another substance?

17. I. Converting Grams to Grams
We know how to go from grams to moles of one substance and moles of one substance to moles of another substance
To go from grams of one substance to grams of another substance, we simply combine these steps

18. Molarity of Substance A Molarity of Substance B
Moles of A
Moles of B
Grams of Substance B
Grams of Substance A
Atoms of Substance A
Atoms of Substance B

19. Class Example
If you react 360 g of C6H12O6 with excess O2 in the following reaction:
C6H12O6 + O2  CO2 + H2O
How many grams of H2O did you react in this reaction?

20. Class Example
If we place 65 g of NaN3 in the steering wheel and the following reaction occurs:
NaN3 (s)  N2 (g) + Na (s)
How many grams of Na do you have before the reaction?

21. Table Talk For the following reaction: N2O5 + H2O  NH4OH + O2
If you start with 36 g of H2O, then how many grams of NH4OH do you react?

22. Table Talk
The Whoosh bottle reaction also involves the following combustion:
C6H12O6 + O2  CO2 + H2O
If I start with 40 g of C6H12O6, then how many grams of H2O will be produced?