1. Adjusting to reality- Limiting and Excess Reactants
Stoich
Adjusting to reality-
Limiting and Excess Reactants

2. Limiting Reactant Bread Peanut butter
Definition: The reactant that limits the amount of product made.
Think of the activity we did with the bread and peanut butter
Which one was the limiting reactant? (the one we ran out of)
Bread
Which one was the excess reactant? (the one we had extra of)
Peanut butter

3. Example 1:
Sodium chloride can be prepared by the reaction of sodium metal with chlorine gas:
2Na + Cl2  2NaCl
Suppose that 6.70 mol Na reacts with mol Cl2.
What is the limiting reactant?
What is the excess reactant?
How many moles of NaCl is produced?

4. Example 2:
The equation for the complete combustion of ethene (C2H4) is :
C2H4 + 3O2  2CO2 + 2H2O
If 2.70 mol C2H4 is reacted with 6.30 mol O2
What is the limiting reactant?
What is the excess reactant?
Calculate the moles of water produced.

5. Example 3:
2Cu + S  Cu2S
80.0g of copper reacts with 25.0 g of sulfur.
What is the limiting reactant?
What is the excess reactant?
What is the maximum number of grams of Cu2S that can be formed?

6. Example 4:
2KBr(aq) + Cl2(aq)  2KCl (aq) + Br2(l)
When g of Cl2 and g of KBr are mixed in solution:
A) What is the limiting reactant?
B) What is the excess reactant?
C) How many grams of Br2 are formed?