Stoichiometry Limiting Reactant Notes
Pancake Recipe again
1 cup flour + 1 cup milk + 1 egg + 0.5 cups blueberries  6 pancakes
How many pancakes can you make with, 4.5 cups flour, 6.5 cups of
milk, 5 eggs and 3.5 cups of blueberries?
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Given the numbers of grams (mass) or the number of moles of each
reactant in an equation
Do 2 calculations solving for the same product in moles or grams
Type 1 Example:
Solve just for limiting reactant – mole to mole
Given: 6.0 moles of sodium in
3.0 moles of water, what is L.R.?
2Na(s) + 2H2O  2NaOH(aq) + H2(g)
(Given)
(Product)
1st
2nd
How much can you make?
What is the Limiting Reactant?
What is the excess Reactant?
Type 2 Example: mass to mole
2Na(s) + 2H2O(l)  2NaOH + H2(g)
Given: 46.0 g sodium reacting with 54.0 g H2O
Which is the L.R.?
1st
2nd
How much can you make?
What is the Limiting Reactant?
What is the excess Reactant?
Type 3 Example: mass to mass
How many grams of hydrogen gas can be produced from 10.0 g sodium
in 32.0 g of water?
1st
2nd
How much can you make?
What is the Limiting Reactant?
What is the excess Reactant?