Chemical Quantities
1.
2.
3.
A chemical equation tells you what reactant
chemicals are used and what product
chemicals are formed.
A chemical equation does tell you the ratio to
mix the chemicals in with the coefficients.
A chemical equation does not tell you how long
the chemical reaction will take, how to mix
the chemicals, or at what temperature.
2 eggs + 3 cup flour +
1.5 cup brown sugar +
1 bag chocolate chips +
1 tsp vanilla +
2/
3
cup butter
= 5 doz. cookies
Scaling Chemical Reactions
_____ moles
2 HgO
______grams

.5
_____moles
moles
2 Hg
______grams
+
O2
_____grams
Stoichiometry : The relationships among
the quantities of reactants and products
involved in a chemical reaction.
a. Balance the chemical equation.
b. Work in moles.
Change all grams to moles using: Moles = grams/molar mass
c. Use the coefficients in the balanced equation to
determine the moles of other chemicals (scaling)
d. If asked for grams, change moles to grams
grams = (moles)(molar mass)
Stoichiometry Worksheet
1. Balance the following equation:
Na
+
H2O

NaOH
+
H2
a. How many moles of NaOH would be produced if you used 0.30 moles of
Na?
b. How many grams of NaOH is your answer to a?
c. How many moles of H2 would be produced if you used 0.30 moles of Na?
d. How many grams of H2 is your answer to c?
1.
2.
Balance the equation.
If we use 22.4 g of Fe2O3, how many grams of Al will
be needed?
3.
How many grams of Al2O3 will be produced?
4.
How many grams of Fe will be produced?
The following reaction shows the chemical reaction
used for the manufacturing of iron.
Fe2O3 (s) + CO (g)  Fe (L) + CO2 (g)
a. How many moles of iron can be made from 10 moles
of Fe2O3 (iron ore)?
b. How many grams is your answer?
Decomposition of Sodium Chlorate
NaClO3 (s) 
NaClO2 (s)
+
O2 (g)
1. How many grams of NaClO2 (s) will be produced if equation 1 is
correct and we start with 1.00 gram of NaClO3?
.
NaClO3 (s) 
NaClO (s)
+
O2 (g)
2. How many grams of NaClO will be produced if equation 2 is
correct and we start with 1.00 gram of NaClO3?
NaClO3 (s) 
NaCl (s)
+
O2 (g)
3. How many grams of NaCl will be produced if equation 3 is
correct and we start with 1.00 gram of NaClO3?
The Haber process is used to make ammonia for fertilizer.
N2 (g) +
H2 (g) 
NH 3(g)
Suppose 25.0 kg of N2(g) and 5.00 kg of H2(g) are mixed and reacted
to form ammonia. Calculate the mass of NH3(g) produced when this
reaction is run to completion.
(
Actual yield
(Theoretical yield
100
Actual yield is the amount of product measured when a
reaction is done
Theoretical yield is the amount of product that should
be produced according to the stoichiometry
calculations.
H2 (g) +
CO(g)

CH3OH(L)
If 68.5 kg of CO is reacted with 8.60 kg of H2, what is the
theoretical yield? If 35.7 kg CH3OH is produced,
what is the % yield?
.625 mol
1.25 mol
Cu
2 AgNO3
+
39.72 g
a.
b.
c.
d.
e.
f.
g.
h.
212.34 g
0.625 mol Cu
39.72 g Cu
1.25 mol Ag
134.84 g Ag
0.625 mol Cu(NO3)2
117.22 g Cu(NO3)2
212.34 g AgNO3
93.38 % yield
1.25 mol

2 Ag
134.84 g
.625 mol
+
Cu(NO3)2
117.22 g