Stoichiometry

Introductory Steps to Use the Road Map

The Steps:

1. Identify the given
2. Identify the unknown
3. Locate on the road map the starting point (the given)
4. Locate on the road map the ending point (the unknown)

---

Example Problem on Using the Road Map:

Given the following equation:

2 Na + 2 H₂O ==> 2 NaOH + H₂

How many grams of water does it take to react with 100.0 g of Na?

1. Identify the given:
·100.0 g of Na

2. Identify the unknown:
·g of water

3. Locate the starting point on the road map:
·The units of the given is "grams" (100.0 g of Na). Therefore, you would start at "Mass of A" on the road map.




4. Locate the ending point on the road map:
·The units of the unknown is "grams" (g of H₂O). In addition, water is a separate substance than Na. Therefore, you would end at "Mass of B" on the road map.