Stoichiometry
Problems
Problem 1
One way to remove NO from
smokestack emissions is to
react it with ammonia:
4 NH3 + 6 NO → 5 N2 + 6 H2O
Fill in the blanks:
16.5 mol NO reacts with ___ mol NH3
9.30 mol NO yields ___ mol N2
0.772 mol N2 requires ___ mol NO
Problem 2
The combustion of butane gas,
C4H10, in air, yields CO2 and
H2O.
Write a balanced equation for
the reaction.
How many moles of butane are
required to form 11.6 mol
CO2?
Problem 3
A tool set contains 4
wrenches, 3 screwdrivers,
and 2 pliers. The
manufacturer has in stock
1000 pliers, 2000
screwdrivers, and 1500
wrenches.
Can an order for 500 tool sets
be filled?
Problem 4
Chlorine and fluorine react to form
gaseous chlorine trifluoride,
ClF3. You start with 3.40 mol Cl2
and 7.16 mol F2.
Write a balanced equation for the
reaction.
What is the limiting reactant?
What is the theoretical yield of
ClF3?
Balance
C6H14 + O2 → CO2 + H2O
Al + HCl → AlCl3 + H2
KClO3 → KClO4 + KCl
Problem 5
Determine the mass percentages
of the compound ammonium
dichromate.
Problem 6
Determine the simplest formula of
a compound with the following
composition:
43.2% K, 39.1% Cl, 17.7% O
Problem 7
Determine the simplest formula of
a compound with the following
composition:
62.1% C, 5.21% H, 12.1% N,
20.7% O
Problem 8
Iron reacts with sulfur to form a
sulfide. If 2.561 g of iron reacts
with 2.206 g of sulfur, what is
the simplest formula of the
sulfide?
Problem 9
The insecticide DDD
contains only C, H, and Cl.
When a 3.200 gram sample
is burned in oxygen, 6.162
gram CO2 and 0.9008 gram
H2O are formed. What is
the simplest formula of
DDD?
Problem 11
Caffeine contains C, H, O and
N. Combustion of 1.000 mg
of caffeine produces 1.83 mg
CO2, 0.4639 mg H2O and
0.2885 mg N2. Estimate the
molar mass of caffeine,
which lies between 150 and
200 g/mol.
Problem 12
Consider separate 100.0 gram
samples of each of the
following:
H2O N2O C3H6O2
CO2
Rank them from greatest to
least number of oxygen
atoms.
Objectives
1. Convert mass quantities to
atoms (or molecules) using
FLC
2. Solve mass-mass problems
using stoichiometry,
theoretical and % yield
3. Use mass %’s to find
empirical, molecular
formulas