Download Limiting Reactants… to the particle level and beyond!

NAME:
Mods:
Limiting Reactants…
to the particle level and beyond!
We have looked at Stoichiometry, and the concept of limiting reactants on
the “nuts and bolts” level, but now it’s time to start applying it to the chemical world.
First, we will look at where the chemistry happens – at the particle level!
Remember, the limiting reactant limits the amount of product that can be
made in a chemical reaction. The other reactant (or reactants) is called the excess
reactant because when the limiting reactant runs out, the excess reactant is still
present! Let’s look at these concepts at the particle level:
1.
Write the balanced equation to represent the synthesis of water:
Below, we see containers that show how many molecules of each reactant that are
available to make water. Given these quantities, draw the water molecules you could
make and then answer the questions.
*Follow the recipe! Use the Mole Ratios!*
+
Hydrogen
Oxygen
Water
a)
which reactant is the limiting reactant? ____________________
b)
which reactant is the excess reactant? _____________________
c)
how many molecules of the excess reactant remained? ____________
d)
how many molecules of water were made?
_______________
2.
Here is the balanced equation for the complete combustion of methane (CH4):
CH4 + 2 O2
CO2 +
2 H2O
Below, we see containers that show how many molecules of each reactant that are
available for the combustion. Given these quantities, draw the carbon dioxide and
water molecules you could make and then answer the questions.
*Follow the recipe! Use the Mole Ratios!*
+
Methane
3.
+
Oxygen
Carbon Dioxide
Water
a)
which reactant is the limiting reactant? ____________________
b)
which reactant is the excess reactant? _____________________
c)
how many molecules of the excess reactant remained? ____________
d)
how many molecules of carbon dioxide were made? _____________
e)
how many molecules of water were made? _______________
Below is the balanced equation for the synthesis of glucose (C6H12O6):
6 C + 6 H2 + 3 O2
C6H12O6
If you were given 144 carbon atoms, 186 hydrogen molecules, and 255 oxygen molecules…
a)
which reactant is the limiting reactant? ____________________
b)
how many molecules of glucose can be made? ________________
c)
which reactants are the excess reactants? ___________________
d)
how many particles of each excess reactant remain?