Name ___________________
Section _____
Intro to Limiting Reactants
Do Now – Balancing Equations and Mole Ratio
Homework Review
Balance the following equation:
____ Zn + ____ HCl → ____ ZnCl2 + ____ H2
Part A
How many moles of Hydrogen gas are produced from three moles of Zinc?
Part B
How many moles of Zinc are needed to produce five 3.5 moles of Zinc (II) Chloride?
Part C
How many moles of Hydrogen are needed to produce 15 moles of Hydrogen Chloride?
Part D
How many liters of HCl are needed to react with eleven liters of Zinc?
Name ___________________
Section _____
Intro to Limiting Reactants
Launch
1. How many of each race car part on the list is needed to assemble 1 race car?
2. How many of each part is needed to assemble 3 cars?
3. Suppose you need to assemble 3 cars. You have 14 tires, 2 cylinders and 3 engines
and 3 bodies, what are the excess and limiting parts?
4. How would you relate this idea to the amount of reactants and products in a
chemical reaction?
Name ___________________
Section _____
Intro to Limiting Reactants
Explore Part I: Intro to Limiting and Excess Reactants
** When the quantity of each reactant in a chemical reaction is given, you must
determine which one is __________________ first. This is defined as the limiting
reactant/reagent.
** The other reactant that is not completely ________________ in the reaction.
This is defined as the excess reactant (________________).
STAMP… repetition is memorization.
Limiting Reactant
● ______________________________________________________
______________________________________________________
● ______________________________________________________
______________________________________________________
Excess Reactant
● ______________________________________________________
______________________________________________________
Let’s identify the steps necessary to successfully find the limiting reactant in a chemical
equation.
1. Write a _________________ equation if one is not provided to you already.
2. For each _________________, calculate the amount of _______________
formed.
a. A _____________ product amount indicates that the
_______________ in question is ___________________.
b. The smaller product amount is the _____________ amount of product
that can be formed.
Name ___________________
Section _____
Intro to Limiting Reactants
Explore Part II: Practice Limiting Reactants
Aluminum combines with Chlorine Gas to produce Aluminum Chloride
1. Write a ______________ chemical equation.
100 grams of Aluminum is combined with 80 grams of Chlorine Gas. Which of the two
reactants limit the amount of Aluminum Chloride produced?
2. Find the amount of ____________ formed from the amount of each
______________ provided in the problem.
a.
Al
b.
Cl2
3. Which amount of ______________ formed is the limiting factor? The excess?
** How much Aluminum Chloride can be formed if there are 100 grams of
Aluminum and 80 grams of Chlorine Gas?
_______________________________________________________
Name ___________________
Section _____
Intro to Limiting Reactants
You Try: Finding the Limiting Reactant
Calculate the mass of Magnesium Oxide possible if 2.4 grams of magnesium
reacts with ten grams of Oxygen Gas.
1. Write a ______________ chemical equation.
2. Find the amount of ____________ formed from the amount of each
______________ provided in the problem.
a.
Mg
b.
O2
4. Which amount of ______________ formed is the limiting factor? The excess?
Name ___________________
Section _____
Intro to Limiting Reactants
Discussion
1. Define the limiting reactant.
2. Define the excess reactant.
3. Explain how our practice with moles for the past few weeks has been
incorporated into finding limiting/excess reactants.