1. Stoichiometry Notes Part II Multi-Step Problems

2. From yesterday… Why are mole/mole problems impractical in a laboratory setting? We don’t ever measure directly in moles!

3. Steps to solve every problem: 1)Write a balanced equation. 2)Put what you have over 1. 3)Convert into moles. 4)Compare using the mole to mole ratio from the equation. 5)Convert into the unit the question asks for.

4. Al + Cl 2  AlCl 3 How many grams of aluminum are needed to produce 22.7g aluminum chloride? Balance the equation first!!!

5. 2 Al + 3 Cl 2  2 AlCl 3 How many grams of aluminum are needed to produce 22.7g aluminum chloride?

6. 2 Al + 3 Cl 2  2 AlCl 3 How many liters of chlorine gas are needed to react with 23.1g aluminum? 23.1 g Al x 1 mole Al x 3 moles Cl 2 x 22.4 L Cl 2 = 28.7 L Cl 2 27.0 g Al 2 moles Al 1 mole Cl 2

7. How many grams of iron (III) oxide can be produced with 17.2g Fe? Balance the equation first!!! Fe + O 2  Fe 2 O 3

8. How many grams of iron (III) oxide can be produced with 17.2g Fe? 17.2 g Fe x 1 mole Fe x 2 moles Fe 2 O 3 x 159.6 g Fe 2 O 3 = 24.6 g Fe 2 O 3 55.8 g Fe 4 moles Fe 1 mole Fe 2 O 3 4 Fe + 3 O 2  2 Fe 2 O 3

9. How many grams of iron will react with 5.25 liters of O 2 (@STP)? 5.25 L O 2 x 1 mole O 2 x 4 moles Fe x 55.8 g Fe = 17.4 g Fe 22.4 L O 2 3 moles O 2 1 mole Fe