1. Limiting reagents

2. CO(g) + 2 H2(g) ⟶ CH3OH(g) Before the reaction has started
After the reaction is complete
CO(g) + 2 H2(g) ⟶ CH3OH(g)

3. Limiting reactant Excess reactant
Used up first in a reaction
Limits the max amount of product that can be produced
Present in greater quantity than needed
Remains at the end (left over)

4. Steps
Use stoichiometry to convert reactant(s) into the desired product
Identify the max amount of product (if two product amounts are given, choose the smaller one)
Identify the limiting reactant (LR); reactant that predicted the smaller amount of product
Identify the excess reactant (ER); reactant that predicted the larger amount of product

5. Example 1
How many grams of silver bromide can be formed when solutions containing 50.0 g of magnesium bromide and g of silver nitrate are mixed together? What is the limiting reactant? What is in excess?

6. Example 2
How many grams of hydrogen chloride can be produced from 1.00 g of hydrogen and 55.0 g of chlorine? What is the limiting reactant? What is in excess?

7. Example 3
How many grams of barium sulfate will be formed from g of barium nitrate and g of sodium sulfate? What is the limiting reactant? What is in excess?