LAB 6: CHEMICAL REACTIONS:
CHEMICAL EQUATIONS
PURPOSE: To perform and recognize different types of chemical reactions.
To complete and balance chemical equations.
To test the Law of Conservation of Mass.
SAFETY CONCERNS:
Always wear safety goggles. Tie back long hair when using flames.
The heavy metals, Silver, Chromium, and Lead, must be disposed in designated waste
containers.
PHYSICAL AND CHEMICAL PROPERTIES:
Each element or compound has unique properties that make it distinguishable from other
elements or compounds. Physical properties, such as color, luster, softness, electrical
conductivity, the temperature at which it melts or boils, crystal structure etc. are characteristics
that are visible or measurable qualities used to identify a substance. Physical changes, such
as melting, boiling, or stretching do not affect the identity of the substance, just its form.
Aluminum, Al, for example, is shiny and malleable (it can be physically stretched into wire,
rolled into pellets, or pounded into sheets and foil). It conducts heat and electricity but is not
magnetic. It has a high melting point (it takes a lot of energy to make it turn from a solid to a
liquid) and it is not soluble (doesn’t dissolve) in water. These characteristics are physical
properties used to describe aluminum.
Chemical properties are not so obvious. They are determined by how a substance changes
or reacts with other substances to form different compounds. When substances react together to
create new and different substances we call the change a chemical change or chemical
reaction.
Aluminum, Al, for example, chemically undergoes a change (chemical reaction) when put in the
presence of hydrochloric acid, HCl. Once reacted, it is no longer aluminum, Al, but has become
a new substance, aluminum chloride, AlCl3. The fact that it reacts with hydrochloric acid is a
characteristic chemical property of aluminum. Aluminum chloride is a completely different
compound with completely different physical properties than those of the aluminum and
hydrochloric acid from which it was made.
CHEMICAL REACTIONS:
Not every chemical will react with every other chemical. However, when a chemical reaction
does occur there are observable clues that indicate to us that a change has indeed taken place.
The following events are measurable or visible indicators that a chemical reaction may have
occurred:
A.
Gas production (bubbles form)
B.
Solid formation (an insoluble solid, called a precipitate, forms)
C.
Color change (not just a dilution of color but a real change)
D.
Temperature change (a reaction that produces heat is exothermic, a reaction that gets
cold is endothermic)
CH104 Lab 6: Chemical Reactions (F15)
79
Many metals will react with acids (sources of H+) to form hydrogen gas (H2). Shown is a series
of some of the most common metals, listed in descending order of reactivity. A metal higher on
the list can replace an ion of a substance on the list below it. As we go up the list from the
bottom to the top the metals:
 reactivity increases. (react more vigorously and quickly)
 lose electrons more easily to readily form positive ions (so corrode more easily)
 becomes stronger reducing agents
A Reactivity Series of Common Metals:
Metals
K
Na
Li
Ca
Mg
Al
Zn
Cr
Fe
Ni
Sn
Pb
H2
Cu
Hg
Ag
Au
Pt
Metal Ion
K+
Na+
Li+
Ca2+
Mg2+
Al3+
Zn2+
Cr2+
Fe2+
Ni2+
Sn2+
Pb2+
H+
Cu2+
Hg2+
Ag+
Au3+
Pt+
Reactivity
reacts with water
reacts with acids
H+ is the acid (included for comparison)
highly unreactive
CHEMICAL EQUATIONS:
Chemical changes are represented by expressions called chemical equations. (Review the
introduction to chemical equations presented in the discussion section of the Lab 1, Burners and Flames.) The
chemical equation to describe the reaction of aluminum with hydrochloric acid is as follows:
2Al(s) + 6HCl(aq)  2AlCl3(aq) + 3H2(g)
Al and HCl on the
left side of the arrow are
reactants.

AlCl3 and H2 on the
right side of the arrow are
products.
This chemical equation can be translated into words. The expression reads:
2Al(s)
=
2 units (atoms or moles) of solid Aluminum
+
=
plus (and, combined with)
6HCl(aq)
=
6 units (molecules or moles) of aqueous (dissolved in water)
hydrochloric acid

2AlCl3(aq)
+
3H2(g)
=
yields (gives, results in, produces)
=
=
=
2 units (molecules or moles) of aqueous Aluminum chloride
and (plus)
3 units (molecules or moles) of hydrogen gas.
Not all substances, when placed together, will undergo a chemical change. If nothing new
happens (no gas formed, no precipitate formed, no color change, or no temperature change) then
we simply write no reaction in place of the products.
CH104 Lab 6: Chemical Reactions (F15)
80
GASES:
When a gas is formed from a chemical reaction we may be able to identify it by observing its
color, odor, and flammability. Never smell a gas directly as it may be toxic. If the smell is
not obvious then gently waft the fumes toward your nose being very careful not to inhale too
much.
The following is a list of the identifying properties of some common gases. Use it to prove the
identity of gases that may be produced in your reactions:
COMMON GAS
PROPERTIES
Colorless, odorless, and not flammable at all.
Large amounts will actually put out a flame so it is used as the gas
in standard fire extinguishers.
Very toxic. Colorless. Has the odor of rotten eggs. (Report this to
Carbon dioxide, CO2
Dihydrogen sulfide, H2S
your instructor immediately. )
Colorless, odorless, but highly flammable. When a burning splint
comes in contact with a test tube of hydrogen it gives a “pop” sound
when the gas ignites.
Red-brown gas with a heavy, burning odor.
It is the toxic gas emitted from some factories and causes edema of
lung tissue. (Report this to your instructor immediately. )
Colorless and odorless. Is necessary for any combustion reaction to
occur. If present it will increase the flammability of other
substances. A glowing splint will burst into flame in the presence
of oxygen.
Toxic gas. Gives off the odor of sulfur when burned.
Hydrogen, H2
Nitrogen dioxide, NO2
Oxygen, O2
Sulfur dioxide, SO2
CONSERVATION OF MASS:
When elements or compounds chemically react to form products, no material (matter) is lost or
gained. All of the atoms used as reactants are converted into products. Every atom of every
element must be accounted for since they are not destroyed or created, just rearranged and
recombined into new things.
The numbers (coefficients) before each formula in a chemical equation indicate how many units
of each reactant are being used or how many units of product are formed. When expressing a
reaction as a chemical equation we use coefficients to balance the equation as an accounting
tool to accurately show that no atoms have been created from nothing or have vanished into
nothing.
Because no matter is lost or gained in a chemical change, the total mass of all of the products
will be the same as the total mass of all the reactants used. In any chemical reaction mass is
maintained or conserved from the beginning to the end. This phenomenon is called the Law of
Conservation of Mass.
The mass of an object is a measurement of the quantity of matter it contains. The weight of an
object is the measurement of how the force of gravity affects it. A quantity of matter will always
have the same mass but may have a different weight at sea level on earth than it does on a
mountain, or in space where the gravitational pull is different. Measuring the mass of an object
in grams assumes that we are at the constant gravitational pull of our planet.
CH104 Lab 6: Chemical Reactions (F15)
81
NOTES:
PROCEDURES:
1
ACTIONS:
CHEMICAL REACTIONS:
I. Metals + Hydrochloric Acid 
1. On separate weighing papers1 obtain
about2 0.10 grams of each of the following
metals:
A. Iron (Fe)
B. Copper (Cu)
C. Zinc (Zn) granules3
D. Magnesium (Mg) ribbon4
E. Aluminum (Al)
Chemical powders and liquids should never be
placed directly on the metal balance pan since they
may cause corrosion. Shiny paper or boats are used
so that powdered materials will slide off easily. If
porous paper, like filter paper or paper towels, were
used instead of shiny materials, then powders might
get caught in the fibers and be lost.
2
The measurement does not have to be exactly 0.10
grams. Anywhere from 0.08 to 0.12 g is fine. Just
record exactly what you have.
3
Zinc is the metal used in the coating of galvanized
materials like nails and buckets.
4
2. Ready 5 large test tubes with rubber
stoppers and label them A-E.
5
3. Into each test tube A-E place 3 mLs of 6M
HCl (6 molar hydrochloric acid6).
4. Have a couple of wooden splints and a
burning laboratory burner nearby for use
once your reactions start.
Magnesium is a light metal commonly used in “Mag”
wheels of race cars.
5
To expedite your process you measure out 15 mLs of
HCl and then divide it evenly between the 5 tubes.
6
Hydrochloric Acid is the acid in your stomach that
aids digestion. It is also used in some brands of toilet
bowl cleaner.
Molarity, M, is a measure of
concentration that indicates the number of moles of
hydrochloric acid in 1 liter of aqueous solution.
7
7
5. Without delay between samples put each
of the 0.10 g metal samples into their
corresponding tube of HCl and stopper the
tubes loosely.8
6. Watch each tube and notice if and how fast
each metal undergoes a chemical
reaction.9 Record your observations on
the report sheet (Box I #A-E). Rank the
metal/HCl reactions in order from fastest
to slowest. (Box IF)
7. Light a wooden splint by placing it in the
flame of a laboratory burner then carefully
bring the burning splint right next to the
mouth of each reaction test tube. Remove
the stopper and quickly ignite the gas.10
8. Determine the identity of the gas produced
in each reaction based on the information
about various common gases given in the
discussion section.
9. Observe each tube again after about several
minutes and record your observations.
82
We want to compare the rate at which these metals
react so we want to have each metal/HCl reaction start
as close to the same time as is reasonable.
8
The stopper must be loose so that it won’t pop off
from any increased pressure in the tube should a gas
be produced in the reaction.
9
Remember that there are several important
observations that will indicate that a chemical reaction
has taken place:
gas production:
bubbles will be visible
solid formation:
cloudiness is evidence of suspended solids
color change:
observable change not just a lightening of
shade by dilution
temperature change:
observable by touching the outside of the tube
with your hands or by placing a thermometer
inside.
Indicate which of these, if any, are present. If none
are present indicate “no reaction”.
10
If you are not quick enough to ignite the gas then the
gas present will escape into the atmosphere and be
gone. If this happens just add a little more zinc
powder to your HCl and try again.
CH104 Lab 6: Chemical Reactions (F15)
II. Other Reactions
1. Sodium Bicarbonate + Acetic Acid 
A. To a large test tube add a “large pea” sized scoop of Sodium
Bicarbonate (Baking soda = NaHCO3) and dissolve it completely
in about12 3 mLs of water.
B. Into the tube of dissolved sodium bicarbonate, pour about 2
mLs (40 drops) of 5% Acetic Acid (vinegar = HC2H3O2) and
stopper it loosely. 8 Record your observations on the report
sheet.9
C. Test the flammability of the gas using a burning wood splint
like you did in part I step 7, and report the identity of the gas.
2. Sodium Hydroxide + Acetic Acid 
A. To a test tube (size doesn’t matter) add a pea sized scoop of
solid Sodium Hydroxide13 (lye or Drano = NaOH).
B. Drop in about 2 mL (40 drops) of 5% Acetic Acid (vinegar =
HC2H3O2).
C. Record your observations on the report sheet.9
3. Sodium Chloride + Silver Nitrate 
A. To a test tube, enter a pea sized scoop of solid Sodium
Chloride (table salt = NaCl) and dissolve it in water (about 1 mL
=20 drops).
B. Insert a thermometer and observe the temperature.
C. Drop in about 0.5 mL (10 drops) of 0.1 M Silver Nitrate
(“wart remover” or cold sore treatment = AgNO3).
D. Record your observations on the report sheet.9
E. Dispose of waste from this reaction in a designated Silver
Waste container. 14
4. Copper + Silver Nitrate 
A. Place a shiny clean15 Copper penny or piece of clean copper
metal into a large test tube or your smallest beaker.
B. Add about 1 mL (20 drops) of 0.1 M Silver Nitrate (“wart
remover” or cold sore treatment = AgNO3).
C. Watch and wait and record your observations on the report
sheet.9
F. Observe the tube again after about 20 minutes and record
your observations.16
D. Dispose of waste from this reaction in a designated Silver
Waste container. 14
12
You do not need to measure the
3 mLs of water exactly in this
reaction. You can estimate 3 mLs
by comparing the level of liquid
in a previously measured 3 mL
sample. If the test tubes are the
same size then just “eye-ball” the
level and that’s close enough
here. We are interested in the
quality of the reaction not the
quantities. As long as the sodium
bicarbonate
is
completely
dissolved the reaction will show
what we need.
13
Avoid
touching
Sodium
Hydroxide. If you get some on
your hands wash immediately
with soap and water. Sodium
Hydroxide is a very strong base
that is caustic to your skin
because it reacts with skin
proteins to destroy them. Strong
bases like this cause more
damage and scarring than do
strong acids.
14
Silver, Ag, is a heavy metal that
can be toxic if ingested in large
amounts. We do not want to put
silver
products
down
the
laboratory drains. It must be
disposed
of
in
specially
designated waste bottles. Besides
being a potentially toxic heavy
metal, silver is very expensive
and can sometimes be mined
from the waste and recycled.
15
Tarnished copper can be
cleaned by washing in a dilute
acid solution such as vinegar (5%
acetic acid).
16
This is an example of a method
to “plate” silver onto copper.
17
5. Zinc + Copper (II) Sulfate 
A. Place a shiny clean Zinc strip or a new galvanized nail3 into
a small test tube.
B. Add about 1 mL (20 drops) of 1.0 M Copper (II) Sulfate
(cupric sulfate = an antifungal agent = CuSO4).
C. Remove the strip as soon as you see evidence of a reaction on
the surface of the Zinc.17
D. Record your observations on the report sheet.9
CH104 Lab 6: Chemical Reactions (F15)
Stop the reaction when you see
a brown copper coating on the
surface of the zinc. This is an
example of a method to “plate”
copper onto zinc. If the reaction
proceeds too far the metal
impurities will continue reacting
and turn black.
83
6. Ammonium Dichromate + Heat 
A. Into your largest dry18 test tube scoop enough solid
B.
C.
D.
E.
Ammonium Dichromate (used in pyrotechnics, lithography, and
photo engraving = (NH4)2Cr2O7) to barely cover the bottom of the
tube.
Clamp the tube onto a ring stand slanted slightly but pointed
away from any people.
Heat the orange solid in the flame of a laboratory burner19
just until the reaction starts to get vigorous, then remove it
from the heat.
Record your observations on the report sheet.9
Dispose of waste from this reaction in a designated
Chromium Waste container.20
7. Magnesium + Oxygen 
A. Do not look directly at this reaction21.
Clear the
workbench area of any paper or flammable materials near a
laboratory burner. Place a beaker of water near the burner.22
B. With a pair of crucible tongs, hold a small strip of
Magnesium ribbon (light metal used in “Mag” wheels = Mg) in the
hottest part of a burner flame just until the reaction begins.
When the reaction starts, remove it from the flame and hold it
a foot above the beaker of water.
C. Record your observations on the report sheet.9
8. Ammonia + Copper (II) Sulfate 
A. To a small test tube or into a spot plate well add about 5
drops of 0.1M Copper (II) Sulfate (cupric sulfate = an antifungal
agent = CuSO4).
B. Add 1 small drop only of 6 M Ammonia (a household cleaner =
23
NH3 dissolved in water = NH4OH) and swirl or stir to mix.
C. Record your observations on the report sheet.9
D. Now to the same tube or well add another 2 drops of 6M
Ammonia, swirl or stir to mix, and record your new
observations.
9. Lead (II) Nitrate + Potassium Iodide 
A. Into a small test tube or into a spot plate well add 3 drops of
0.1M Lead (II) Nitrate (Pb(NO3)2). Observe any color.
B. Add 3 drops of 0.1M Potassium Iodide (KI). Record your
observations.
C. Dispose of the waste from this reaction in a designated lead
waste container.24
18
Be sure the tube is very dry. A
wet tube may crack when entered
into a flame.
19
Gently heat the tube by moving
the flaming burner back and forth
under the suspended test tube just
until the reaction gets going.
20
Chromium, Cr, is a heavy metal
that can be toxic if ingested in
large amounts. We do not want
to put chromium products down
the laboratory drains. It must be
disposed
of
in
specially
designated waste bottles.
21
The bright light produced from
this reaction can damage your
eyes similar to looking directly at
the sun. Avoid looking directly at
the light but turn your head and
try to glance out of the corner of
your eyes.
22
Burning
magnesium
gets
extremely hot and fragments can
drop from the burning ribbon.
The beaker of water is to catch
any dropping product that could
damage the tabletop.
23
Ammonia, NH3, is a gas. The
common ammonia household
cleaners are actually gaseous
ammonia dissolved in water.
When ammonia gas is dissolve in
water it becomes Ammonium
Hydroxide, NH4OH.
24
Lead, Pb, is a heavy metal that
can be toxic if ingested in large
amounts. We do not want to put
lead products down the laboratory
drains. It must be disposed of in
specially
designated
waste
bottles.
III. LAW OF CONSERVATION OF MASS:
1.
2.
3.
4.
5.
84
Carry out one of the experiments in this lab to prove the Law of Conservation of Mass.
Record any observations and results.
Make conclusions.
Discuss potential errors or potential design modifications.
Postulate further questions or experiments that your experiment might inspire.
CH104 Lab 6: Chemical Reactions (F15)
LAB 6: CHEMICAL REACTIONS
NAME_____________
PRE LAB EXERCISES:
DATE______________
1.___
A gas emitted from a reaction is brown and has a noxious odor. The gas could be:
A. Carbon monoxide
B. Hydrogen
C. Nitrogen dioxide
D. Hydrogen Sulfide
E. Carbon dioxide
2.___
List all of following compounds that should never be disposed of in the laboratory sinks.
A. Sodium Chloride
C. Chromium compounds
B. Silver compounds
D. Hydrochloric Acid
3.
List the clues that indicate evidence that a chemical reaction has occurred.
4.
State the Law of Conservation of Mass.
5.
You will be asked in section III of this lab to choose a reaction from among the chemical
reactions in this laboratory and design an experiment that would prove or disprove the Law of
Conservation of Mass.
A. How might you most efficiently go about acquiring the mass of starting materials before
reacting them?
B. What specifically will you look for/observe that will prove or disprove the law of
conservation of mass? (How will you know when you have the answer?)
C. How might the uncertainty of the balance affect your conclusions?
CH104 Lab 6: Chemical Reactions (F15)
85
86
CH104 Lab 6: Chemical Reactions (F15)
LAB 6: CHEMICAL REACTIONS
NAME___________________
REPORT:
PARTNER_________DATE___
I. METALS WITH HYDROCHLORIC ACID:
A. Iron + Hydrochloric Acid
OBSERVATIONS:
Complete and balance the chemical equation or put No Rxn
___Fe + ___HCl 
______List any of the following that are true about this reaction:
A. Gas production, B. Solid formation, C. Color change,
D. Temperature rises or energy released; exothermic
E. Temperature lowers or energy absorbed; endothermic
N. No reaction.
Other observations characteristic to this reaction? __________
B. Copper + Hydrochloric Acid
______List any of the following that are true about this reaction:
A. Gas production, B. Solid formation, C. Color change,
D. Temperature rises or energy released; exothermic
E. Temperature lowers or energy absorbed; endothermic
N. No reaction.
Other observations characteristic to this reaction? __________
C. Zinc + Hydrochloric Acid
______List any of the following that are true about this reaction:
A. Gas production, B. Solid formation, C. Color change,
D. Temperature rises or energy released; exothermic
E. Temperature lowers or energy absorbed; endothermic
N. No reaction.
Other observations characteristic to this reaction? __________
D. Magnesium + Hydrochloric Acid
______List any of the following that are true about this reaction:
A. Gas production, B. Solid formation, C. Color change,
D. Temperature rises or energy released; exothermic
E. Temperature lowers or energy absorbed; endothermic
N. No reaction.
Other observations characteristic to this reaction? __________
E. Aluminum + Hydrochloric Acid
______List any of the following that are true about this reaction:
A. Gas production, B. Solid formation, C. Color change,
D. Temperature rises or energy released; exothermic
E. Temperature lowers or energy absorbed; endothermic
N. No reaction.
Other observations characteristic to this reaction? __________
Type of Reaction = Single Replacement
Identity of gas produced =___________
(Give evidence for the identity of the gas produced).
Complete and balance the chemical equation or put No Rxn
___Cu + ___HCl 
Type of Reaction = Single Replacement
Identity of gas produced =___________
(Give evidence for the identity of the gas produced). .
Complete and balance the chemical equation or put No Rxn
___Zn + ___HCl 
Type of Reaction = Single Replacement
Identity of gas produced =___________
(Give evidence for the identity of the gas produced).
Complete and balance the chemical equation or put No Rxn
___Mg + ___HCl 
Type of Reaction = Single Replacement
Identity of gas produced =___________
(Give evidence for the identity of the gas produced).
Complete and balance the chemical equation or put No Rxn
___Al + ___HCl 
Type of Reaction = Single Replacement
Identity of gas produced =___________
(Give evidence for the identity of the gas produced).
F. Activity of Metals: Rank the above metals in order of decreasing activity.
Experimental Rank: Fastest
______ > ______ > ______ > ______ > _______ Slowest
(from your results)
Expected Rank:
Fastest
______ > ______ > ______ > ______ > _______ Slowest
(from discussion section)
Explanation/Analysis: Compare your actual results with that expected. Explain any differences.
CH104 Lab 6: Chemical Reactions (F15)
87
II. OTHER REACTIONS
1. Sodium Bicarbonate + Acetic Acid
______List any of the following that are true about this reaction:
A.
B.
C.
D.
E.
N.
Gas production,
Solid formation,
Color change,
Temperature rises or energy released; exothermic
Temperature lowers or energy absorbed; endothermic
No reaction.
NaHCO3 + HC2H3O2  NaC2H3O2 + H2CO3
↓
H2O + CO2
____ Type of Reaction:
A. Combination
B. Decomposition
C. Single Replacement
D. Double Replacement
Other observations
Identity of gas produced =___________
(Give evidence for the identity of the gas produced).
2. Sodium Hydroxide + Acetic Acid
Complete and balance the chemical equation or put No Rxn
NaOH + HC2H3O2  NaC2H3O2 + H2O
______List any of the following that are true about this reaction:
A.
B.
C.
D.
E.
N.
Gas production,
Solid formation,
Color change,
Temperature rises or energy released; exothermic
Temperature lowers or energy absorbed; endothermic
No reaction.
3. Sodium Chloride + Silver Nitrate
______List any of the following that are true about this reaction:
A.
B.
C.
D.
E.
N.
Gas production,
Solid formation,
Color change,
Temperature rises or energy released; exothermic
Temperature lowers or energy absorbed; endothermic
No reaction.
4. Copper + Silver Nitrate
______List any of the following that are true about this reaction:
A.
B.
C.
D.
E.
N.
Gas production,
Solid formation,
Color change,
Temperature rises or energy released; exothermic
Temperature lowers or energy absorbed; endothermic
No reaction.
____ Type of Reaction:
A. Combination
B. Decomposition
C. Single Replacement
D. Double Replacement
Other observations
Complete and balance the chemical equation or put No Rxn
___ NaCl + _____AgNO3 
____ Type of Reaction:
A. Combination
B. Decomposition
C. Single Replacement
D. Double Replacement
Other observations
Complete and balance the chemical equation or put No Rxn
___ Cu + ____AgNO3 
____Type of Reaction:
A. Combination
B. Decomposition
C. Single Replacement
D. Double Replacement
Other observations
The gray solid produced is __________
5. Zinc + Copper (II) Sulfate
______List any of the following that are true about this reaction:
A.
B.
C.
D.
E.
N.
Gas production,
Solid formation,
Color change,
Temperature rises or energy released; exothermic
Temperature lowers or energy absorbed; endothermic
No reaction.
Complete and balance the chemical equation or put No Rxn
___ Zn + _____CuSO4 
____Type of Reaction:
A. Combination
B. Decomposition
C. Single Replacement
D. Double Replacement
Other observations
The brown solid produced is __________
88
CH104 Lab 6: Chemical Reactions (F15)
6. Ammonium Dichromate + Heat
Complete and balance the chemical equation or put No Rxn
(NH4) 2Cr2O7  Cr2O3 + N2 + 4H2O
______List any of the following that are true about this reaction:
A.
B.
C.
D.
E.
N.
Gas production,
Solid formation,
Color change,
Temperature rises or energy released; exothermic
Temperature lowers or energy absorbed; endothermic
No reaction.
C. Single Replacement
D. Double Replacement
Other observations
____Mg + ____O2 
______List any of the following that are true about this reaction:
Gas production,
Solid formation,
Color change,
Temperature rises or energy released; exothermic
Temperature lowers or energy absorbed; endothermic
No reaction.
8. Ammonia + Copper (II) Sulfate
______List any of the following that are true about this reaction:
A.
B.
C.
D.
E.
N.
A. Combination
B. Decomposition
Complete and balance the chemical equation or put No Rxn
7. Magnesium + Oxygen
A.
B.
C.
D.
E.
N.
____Type of Reaction:
Gas production,
Solid formation,
Color change,
Temperature rises or energy released; exothermic
Temperature lowers or energy absorbed; endothermic
No reaction.
_A_Type of Reaction:
A. Combination
B. Decomposition
C. Single Replacement
D. Double Replacement
Other observations
Complete and balance the chemical equation or put No Rxn
.
NH3 + CuSO4  CuSO4 NH3
____Type of Reaction:
A. Combination
B. Decomposition
C. Single Replacement
D. Double Replacement
Other observations
After 1 drop ______________________________
After 2 more drops__________________________
9. Lead (II) Nitrate + Potassium Iodide
______List any of the following that are true about this reaction:
A.
B.
C.
D.
E.
N.
Gas production,
Solid formation,
Color change,
Temperature rises or energy released; exothermic
Temperature lowers or energy absorbed; endothermic
No reaction.
Complete and balance the chemical equation or put No Rxn
___Pb(NO3)2 + ___KI 
____Type of Reaction:
A. Combination
B. Decomposition
C. Single Replacement
D. Double Replacement
Other observations
CH104 Lab 6: Chemical Reactions (F15)
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III. LAW OF CONSERVATION OF MASS:
Question:
Is the Law of Conservation of Mass true?
A. Reaction to Study: Write out the complete reaction. (Hints: It would simplify your design to choose a
reaction that does not give off a gas. Although other reactions in today’s lab can be used you might find reaction 4, 8, or 9 straightforward.)
B. Experimental Procedure: (Give instructions that others could follow to verify conservation of mass )
A.
B.
C.
D.
E.
F.
C. Results: (Report actual data obtained)
Reagents
Products
Mass of beaker + test tubes + reagents before reacting.
Mass of beaker + test tubes + products after reacting.
Reported to accuracy of the balance. ____________g’s
Reported to accuracy of the balance. ____________g’s
Rounded to 1 place behind the decimal. __________ g’s
Rounded to 1 place behind the decimal. __________g’s
Observations: Describe observations characteristic to this reaction and to the mass information acquired.
D. Analysis/Explanation/Conclusion: (Analyze and make conclusions from the data obtained. State
your conclusion taking into account sig figs and uncertainty in balance. What does your data mean?)
E. Error Analysis: (Give warnings, advice, or modifications for future experiments. Give potential for errors.)
F.
Why was it suggested that you choose a reaction to study that did not produce a gas? How might that
complicate your experimental design? Be specific.
G. Further Question(s): (What new questions might this experiment inspire?)
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CH104 Lab 6: Chemical Reactions (F15)
LAB 6: CHEMICAL REACTIONS
NAME____________
RELATED EXERCISES:
1. Classify each of the following as a Physical property (P) or a Chemical property (C).
___ Silver conducts an electric current.
___ Aluminum metal disappears when added to hydrochloric acid.
___ Sugar cubes disappear when added to warm water.
___ Mercury has a density of 13.6 g/mL.
___ Gasoline burns in an automobile engine.
___ Water freezes at 0oC.
2. Complete and balance the following equations showing complete combustion of hydrocarbons:
(Hint: Remember Flames lab; what are the products of complete combustion of a carbon-hydrogen compound?)
A. ____ CH4 + ____ O2 
B. ____ C5H12 + ____ O2 
3. Balance the following chemical equations:
+ ____ O2 
_____ CO2 + _____ H2O
B. ____ C2H6O + ____ O2 
_____ CO2 + _____ H2O
C. ____ C4H10
+ ____ O2 
_____ CO2 + _____ H2O
D. ____ NaOH
+ ____ (NH4)3PO4 
E. ____ Mg3N2
+ _____ H2O
A. ____ C3H8
F. ____ FeS2
G. ____ S8

_____ Na3PO4 + _____ H2O + _____NH3
_____ Mg(OH)2
+ _____ H2O + ____ O2
+ _____ AsF5
H. ____ Mg3(PO4)2


_____ FeSO4
_____ S16(AsF6)2
+ _____ H2SO4 
+ _____NH3
+ _____H2SO4
+ _____ AsF3
_____ MgSO4
CH104 Lab 6: Chemical Reactions (F15)
+ _____H3PO4
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4.
Complete the missing parts of the following table:
(All answers are hidden in the discussion, procedures, or side notes of this laboratory exercise.)
Chemical Name
Chemical Formula
A. Acetic Acid
B. Ammonia
C. Ammonium Dichromate
D. Copper (II) Sulfate
E. Hydrochloric Acid
F. Silver Nitrate
G. Sodium Bicarbonate
H. Sodium Chloride
I. Sodium Hydroxide
J. Zinc
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CH104 Lab 6: Chemical Reactions (F15)
Common Function