1. Mr. Quinn & Ms. Tom February 10, Aim: How do we determine the limiting reagent in a chemical reaction? Do Now: balance the following chemical equations. ___ CH4 + ___ O2  __ CO2 + ___ H2O ___ CaO + ___ PbCO3  __ CaCO3 + ___ PbO

2. The Steps Balance the equation
Solve for the amount of product formed for each reactant
You will get different numbers
Whichever reactant formed a smaller amount of product is your limiting reagent.

3. Example 1: A Tabletop Volcano
Paper Mache volcanos bubble up because of the reaction between C2H4O2 and NaHCO3, according to the following balanced equation. If 10 g of C2H4O2 and 10 g of NaHCO3 are combined, which is the limiting reagent?
C2H4O2 + NaHCO3  NaC2H3O2 + H2CO3

4. Example 1: A Tabletop Volcano
C2H4O2 + NaHCO3  NaC2H3O2 + H2CO3

5. Example 2: The Human Body
Glucose (C6H12O6) is broken down to CO2 and H2O by the following unbalanced equation. If 180 g of glucose are reacted with 90 g of O2, what is the limiting reagent?
C6H12O O2  CO H2O

6. Example 2: The Human Body
1 C6H12O6 + 6 O2  6 CO2 + 6 H2O

7. Example 3: Architecture
Zinc protects iron from rusting by being oxidized according to the following unbalanced equation. If 120 g of zinc encounter 120 g of O2, which is the limiting reagent?
Zn O2  ZnO

8. Example 3: Architecture
2 Zn + 1 O2  2 ZnO

9. Your Turn!