Lesson Plan : Stoichiometry
This lesson plan is intended to be a guide to see how a demonstration might fit in to the lesson,
information wise. This lesson plan does not contain the modes of how to teach, rather a
suggested outline of information.
Students will:


know how to convert between amounts of reactants and amounts of products using
stoichiometric coefficients
calculate the amount of product/reactant given another amount of a substance in the
same reaction
Background Knowledge Assumed
𝑚𝑎𝑠𝑠

students can manipulate: moles = 𝑚𝑜𝑙𝑎𝑟 𝑚𝑎𝑠𝑠

students can manipulate: moles =

students can manipulate: density

students can balance chemical reactions
𝑚𝑜𝑙𝑒𝑐𝑢𝑙𝑒𝑠
𝐴𝑣𝑜𝑔𝑎𝑑𝑟𝑜′ 𝑠 𝑛𝑢𝑚𝑏𝑒𝑟
𝑚𝑎𝑠𝑠
= 𝑣𝑜𝑙𝑢𝑚𝑒
Hook
The instructor does the demonstration “Genie in a Bottle”
Lesson
1. What did you see during the demo?
Students will answer steam coming out of the flask.
You saw a chemical reaction. If we want to determine how much steam was released we
can do that using the balanced chemical equation:
KI
2H2O2 → 2H2O + O2
2. You can use the balanced chemical equation to calculate the amount of product formed
if you know the amount of a reactant, or you can find the amount of reactant used of
you know that amount of a product. You can do this because of moles. The coefficients
in an equation are the ratio of one compound to another. In the reaction we just
balanced, there are 2 moles of hydrogen peroxide for every 2 moles of water. So if you
know the moles of hydrogen peroxide that you start with you can use the ratio to
calculate the moles of steam (water) formed. For example, say you start with 0.5 moles
of H2O2:
0.5 𝑚𝑜𝑙 𝐻2 𝑂2
2 𝑚𝑜𝑙 𝐻2 𝑂
x
= 0.5 mol H2O
2 𝑚𝑜𝑙 𝐻2 𝑂2
The units top and bottom cancel, and you always want to set it up so that they cancel,
and that the units you’re looking for are on top.
3. Do another example calculating number of moles of O2 starting with 0.5 mol H2O2.
http://sites.jmu.edu/chemdemo
JMU Department of Chemistry and Biochemistry
4. Remember the other ways that we learned to calculate moles, we can use any of them
𝑚𝑎𝑠𝑠
to give us the moles of something in order to do calculations like this. (moles = 𝑚𝑜𝑙𝑎𝑟 𝑚𝑎𝑠𝑠
𝑚𝑜𝑙𝑒𝑐𝑢𝑙𝑒𝑠
moles = 𝐴𝑣𝑜𝑔𝑎𝑑𝑟𝑜′ 𝑠 𝑛𝑢𝑚𝑏𝑒𝑟)
There is a set of practice problems that goes along with this lesson, found under Genie
in a Bottle. It practices balancing reactions and doing stoichiometric calculations to go
along with this lesson.
There is an additional problem set to go along with this demonstration (Genie in a Bottle)
It practices calculating moles and calculating the amount of product formed.
http://sites.jmu.edu/chemdemo
JMU Department of Chemistry and Biochemistry