Experiment 6 – Types of Reactions
Name __________________
Lab Section __________________
Experiment 6 - Types of Reactions
Introduction
There are six basic reactions in chemistry: combination, decompositions, single replacement,
double replacement, neutralization, and combustion. This lab will demonstrate all of these
reactions, except combustion.
In general, each of these reactions can be thought of as follows:
Combination:
𝐴 + 𝑋 → 𝐴𝑋
Where, on the reactant side, A and X are two elements, or an element and a compound; and on
the product side a new compound is formed (physical states can vary).
Decomposition:
𝐴𝑋 → 𝐴 + 𝑋
Where, on the reactant side, AX is a compound; and on the product side, A and X are elements
or new compounds (physical states can vary).
Single Replacement:
𝐴 (𝑠) + 𝐵𝑋(𝑎𝑞) → 𝐵(𝑠 𝑜𝑟 𝑔) + 𝐴𝑋(𝑎𝑞)
Where, on the reactant side, A is an element (usually a solid) and BX is an solution; and on the
product side B is the other element (usually a solid, but can also be a gas, depending on that
element’s natural physical state) and AX is a new solution.
Double Replacement:
𝐴𝑋 (𝑎𝑞) + 𝐵𝑍(𝑎𝑞) → 𝐴𝑋(𝑎𝑞) + 𝐵𝑍 (𝑠)
Where, on the reactant side, AX and BZ are aqueous solutions; and on the product side, a
precipitate (solid) and a new aqueous solution are formed.
Neutralization:
𝐻𝐴 (𝑎𝑞) + 𝐵𝑂𝐻 (𝑎𝑞) → 𝐴𝐵(𝑎𝑞) + 𝐻𝑂𝐻 (𝑙)
Where, on the reactant side, HA is an acid and BOH is a base; and on the product side, AB is an
aqueous salt solution and liquid water is formed. This water is often written as HOH instead of
the familiar H2O, as it aids in balancing the reaction. This is merely a convention.
Combustion:
𝐶𝑥 𝐻𝑦 𝑂𝑧 + 𝑂2 (𝑔) → 𝐶𝑂2 (𝑔) + 𝐻2 𝑂 (𝑔)
Where, on the reactant side, CxHyOz is a hydrocarbon (a compound containing carbon and
hydrogen and sometimes oxygen in a stoichiometric ratio) and oxygen; and on the product side,
CO2 and water are formed (stoichiometry will vary).
Experiment 6 – Types of Reactions
Name __________________
Lab Section __________________
It is important that the physical states of these reactants and products be identified in the
chemical equation. Using the symbols (s), (l), (g), and (aq), the physical states can be denoted as
solid, liquid, gas, and aqueous, respectively. These physical states are usually determined by
observation, though later on predictions can be made using certain guidelines (as in the cases of
single, double, and neutralization reactions).
It is useful to note that products of a combination reaction can usually be determined by the
reactants involved, especially if the reactants are a metal and a nonmetal (two nonmetals is much
more difficult). In this case, it is important to remember to balance the charges of the respective
ions that would form the final product. For instance,
𝐴𝑙 (𝑠) + 𝑂2 (𝑔) → 𝐴𝑙2 𝑂3 (𝑠)
Knowing that aluminum is Al3+ and oxygen is O2-, the least common multiple, 6, is identified.
This means that 2 Al3+ will combine with 3 O2- to form Al2O3. This creates a charge neutral
compound. The overall reaction can then be balanced by ensuring that the total number of each
of the atoms on the reactant side and the product side are equal. (note, the above reaction is, of
course, not balanced, but could easily be done)
For the decomposition reactions, there are really only a handful of reactions in which the
products can be predicted. Two of these reactions are the decomposition of the metal hydrogen
carbonate and the metal carbonates. These are usually done using heat. In general these
reactions follow these rules:
𝑀𝐻𝐶𝑂3 (𝑠) → 𝑀𝐶𝑂3 (𝑠) + 𝐻2 𝑂 (𝑔) + 𝐶𝑂2 (𝑔)
Where M is the metal and the exact composition of the metal hydrogen carbonate and metal
carbonate is determined by the charge of the metal.
𝑀𝐶𝑂3 (𝑠) → 𝑀𝑂 (𝑠) + 𝐶𝑂2 (𝑔)
Where M is the metal and the exact composition of the oxide formed is determined by the metal
charge.
In the case of single replacement reactions, it is the activity series of metals that will determine if
the reaction will occur, and what the products will be. A simple mnemonic will aid in useful in
using the activity series. This mnemonic is, “the metal before replaces the ion after”. By using
the following activity series, along with this mnemonic, the products are easily determined. The
activity series is as follows
Activity Series of Metals
Li > K > Sr > Ca > Na > Mg >
Al > Zn > Cr > Fe > Cd > Co > Ni > Sn > Pb >
(H) > Cu > Hg > Ag > Pt > Au
Experiment 6 – Types of Reactions
Name __________________
Lab Section __________________
This activity series is in order of most reactive to least reactive, with lithium being the most and
gold being the least reactive. Hydrogen, written as (H), marks the transition between those
metals that do react with acids (those before it), and those that do not (those after it). To use the
mnemonic, think of dropping a chunk of that metal into a solution containing the other metal ion.
For instance, dropping a copper wire into a solution of silver nitrate reveals that since the copper
metal is “before” the silver ion, it will replace the silver in solution and the silver will deposit out
in its normal state (solid in this case). If, however, a chunk of silver were put into a copper
nitrate solution, no reaction would take place since the silver is not “before” the copper in the
activity series.
One last distinction about the order of the activity series you may notice is that the top row
comes all from Groups 1 and 2 on the periodic table, the middle row is comprised of the
transition metals, and the bottom row are the “noble metals”, those that do not react with acids.
For the double replacement reactions, there is a method for determining which of the products is
the precipitate. These guidelines are referred to as solubility rules. Follow the guidelines below,
in order, to determine which of the products will be soluble, and which will be the precipitate.
Rules for Determining Solubility
1)
2)
3)
4)
5)
6)
7)
All Li+, Na+, K+, NH4+ are Soluble
All NO3-, C2H3O2-, and ClO4- are Soluble
All Ag+, Hg2+, Pb2+, and Pb4+ are Insoluble
All Cl-, Br-, and I- are Soluble
All OH-, S2-, O2-, and CO32- are Insoluble
All SO42- are Soluble (except Ca2+ and Ba2+)
If not found here, assume Insoluble
Finally, it should be noted that by merely looking at the written equation, the evidence of the
chemical reaction can usually be seen. There are four evidences of a chemical change. That is to
say, if you see one, or more, of these, it indicates that a reaction has taken place. These four
evidences are: permanent color change, gas released (g), precipitate (s), and heat/light being
produced or absorbed. Look for these evidences throughout this lab.
Experiment 6 – Types of Reactions
Name __________________
Lab Section __________________
Procedure
Combination Reaction: Instructor Demonstration
Magnesium burning in air
Sulfur burning in air
Decomposition Reaction:
CuSO4: Place a pea sized portion of copper (II) sulfate, CuSO4∙5H2O, into a large test tube.
Using a test tube holder, gently heat the test tube over a Bunsen burner. Note any changes
you see in the powder and the test tube. See Figure 6.1.
NaHCO3: Place enough sodium hydrogen carbonate (baking soda), NaHCO3, to lightly
cover the bottom of an Erlenmeyer flask. Place the flask on a ring stand with wire gauze to
support the flask on an iron ring.
With no flame under the flask, hold a burning splint directly on top of the mouth of the
Erlenmeyer flask. Note how long the splint will burn. See Figure 6.2.
Heat the flask with the Bunsen burner and wait until moisture is observed at the mouth of
the flask. Hold a burning splint above the mouth of the flask and observe how long the
splint will burn.
Figure 6.1: Heating of CuSO4
Figure 6.2: Baking Soda Decomposition
Experiment 6 – Types of Reactions
Name __________________
Lab Section __________________
Single Replacement: Leave all test tubes in the rack while doing these experiments
Put 20-30 drops of hydrochloric acid, HCl, into a small test tube. Add a piece of magnesium
metal to the acid and note any changes that occur.
Put ~2 mL of water into a small test tube. Add a piece of calcium metal to the water and note
any changes that occur.
Place 20-30 drops of silver nitrate, AgNO3, into a small test tube. Place a piece of copper
wire into the test tube. Set the test tube aside to allow time for the reaction to take place.
Note any changes that occur.
Double Replacement:
Put 10 drops of potassium carbonate, K2CO3, into three separate test tubes. To the first test
tube, add 10 drops of silver nitrate, AgNO3. To the second test tube, add 10 drops of copper
(II) nitrate, Cu(NO3)2. To the third test tube, add 10 drops of aluminum nitrate, Al(NO3)3.
Note any changes that occur.
Put 10 drops of sodium phosphate, Na3PO4, into three separate test tubes. To the first test
tube, add 10 drops of silver nitrate, AgNO3. To the second test tube, add 10 drops of copper
(II) nitrate, Cu(NO3)2. To the third test tube, add 10 drops of aluminum nitrate, Al(NO3)3.
Note any changes that occur.
Neutralization:
Put 10 drops of nitric acid, HNO3, sulfuric acid, H2SO4, and phosphoric acid, H3PO4, into
three separate test tubes. Add two drops of phenolphthalein to each of the test tubes. This
will act as the indicator for this reaction. Add sodium hydroxide, NaOH, to each of the test
tubes. Note how many drops it takes until a permanent color change is observed. You may
have to gently shake the test tube to mix the solutions. Do NOT put your finger over the lip
of the test tube and shake the solution. Your instructor will show you the proper way to mix
solutions in test tubes.
Experiment 6 – Types of Reactions
Name __________________
Lab Section __________________
Prelaboratory Questions
What do the symbols (s), (l), (g), and (aq) mean?
What are the four evidences of a chemical reaction?
Indicate which of the following reactions would occur? (use the activity series listed on page
XXXXX)
𝐹𝑒 (𝑠) + 𝐻𝐶𝑙(𝑎𝑞) →
𝐾 (𝑠) + 𝐻2 𝑂 (𝑙) →
𝐴𝑢 (𝑠) + 𝐾𝑁𝑂3 (𝑎𝑞) →
Indicate which of the following is soluble in water? (use the solubility rules listed on page
XXXXXX)
NaCl
Fe(NO3)2
Fe2O3
CaO
(NH4)3PO4
Experiment 6 – Types of Reactions
Name __________________
Lab Section __________________
Data Table
Observation
Combination

𝑀𝑔(𝑠) + 𝑂2 (𝑔) →
__________________________

𝑆(𝑠) + 𝑂2 (𝑔) →
__________________________
Decomposition

𝐶𝑢𝑆𝑂4 · 5𝐻2 𝑂 (𝑠) →
𝑁𝑎𝐻𝐶𝑂3 (𝑠) →
__________________________
__________________________

𝑁𝑎𝐻𝐶𝑂3 (𝑠) →
__________________________
Single Replacement
𝑀𝑔 (𝑠) + 𝐻𝐶𝑙(𝑎𝑞) →
__________________________
𝐶𝑎 (𝑠) + 𝐻2 𝑂 (𝑙) →
__________________________
𝐶𝑢 (𝑠) + 𝐴𝑔𝑁𝑂3 (𝑎𝑞) →
__________________________
Double Replacement
𝐾2 𝐶𝑂3 (𝑎𝑞) + 𝐴𝑔𝑁𝑂3 (𝑎𝑞) →
__________________________
𝐾2 𝐶𝑂3 (𝑎𝑞) + 𝐶𝑢(𝑁𝑂3 )2 (𝑎𝑞) →
__________________________
𝐾2 𝐶𝑂3 (𝑎𝑞) + 𝐴𝑙(𝑁𝑂3 )3 (𝑎𝑞) →
__________________________
𝑁𝑎3 𝑃𝑂4 (𝑎𝑞) + 𝐴𝑔𝑁𝑂3 (𝑎𝑞) →
__________________________
𝑁𝑎3 𝑃𝑂4 (𝑎𝑞) + 𝐶𝑢(𝑁𝑂3 )2 (𝑎𝑞) →
__________________________
𝑁𝑎3 𝑃𝑂4 (𝑎𝑞) + 𝐴𝑙(𝑁𝑂3 )3 (𝑎𝑞) →
__________________________
Neutralization
𝐻𝑁𝑂3 (𝑎𝑞) + 𝑁𝑎𝑂𝐻 (𝑎𝑞) →
_____________________________
𝐻2 𝑆𝑂4 (𝑎𝑞) + 𝑁𝑎𝑂𝐻 (𝑎𝑞) →
_____________________________
𝐻3 𝑃𝑂4 (𝑎𝑞) + 𝑁𝑎𝑂𝐻 (𝑎𝑞) →
_____________________________
Experiment 6 – Types of Reactions
Name __________________
Lab Section __________________
Postlaboratory Questions
Complete and balance the following reactions
Combination
magnesium + oxygen
→
magnesium oxide (s)

____𝑀𝑔(𝑠) + ____ 𝑂2 (𝑔) →
sulfur
+ oxygen
→
sulfur dioxide (g)

____𝑆(𝑠) + ____ 𝑂2 (𝑔) →
Decomposition
copper sulfate pentahydrate → copper sulfate (s) + water (g)

____𝐶𝑢𝑆𝑂4 · _5_𝐻2 𝑂 (𝑠) →
sodium hydrogen carbonate → sodium carbonate (s) + carbon dioxide (g) + water (g)
____𝑁𝑎𝐻𝐶𝑂3 (𝑠) →
Single Replacement
magnesium + hydrochloric acid
→ magnesium chloride (aq) + hydrogen (g)
____𝑀𝑔 (𝑠) + ____𝐻𝐶𝑙(𝑎𝑞) →
calcium + water
→
calcium hydroxide (s) + hydrogen (g)
____𝐶𝑎 (𝑠) + ____𝐻2 𝑂 (𝑙) →
copper + silver nitrate
→
copper (II) nitrate (aq) + silver (s)
____𝐶𝑢 (𝑠) + ____𝐴𝑔𝑁𝑂3 (𝑎𝑞) →
Experiment 6 – Types of Reactions
Name __________________
Lab Section __________________
Double Replacement
silver nitrate (aq) + potassium carbonate (aq) → silver carbonate (s) + potassium nitrate (aq)
____ 𝐴𝑔𝑁𝑂3 (𝑎𝑞) + ____ 𝐾2 𝐶𝑂3 (𝑎𝑞) →
copper (II) nitrate (aq) + potassium carbonate (aq) → copper (II) carbonate (s) + potassium nitrate (aq)
____𝐶𝑢(𝑁𝑂3 )2 (𝑎𝑞) + ____ 𝐾2 𝐶𝑂3 (𝑎𝑞) →
aluminum nitrate (aq) + potassium carbonate (aq) → aluminum carbonate (s) + potassium nitrate (aq)
____𝐴𝑙(𝑁𝑂3 )3 (𝑎𝑞) + ____ 𝐾2 𝐶𝑂3 (𝑎𝑞) →
silver nitrate (aq) + sodium phosphate (aq) → silver phosphate (s) + sodium nitrate (aq)
____ 𝐴𝑔𝑁𝑂3 (𝑎𝑞) + ____ 𝑁𝑎3 𝑃𝑂4 (𝑎𝑞) →
copper (II) nitrate (aq) + sodium phosphate (aq) → copper (II) phosphate (s) + sodium nitrate (aq)
____ 𝐶𝑢(𝑁𝑂3 )2 (𝑎𝑞) + ____ 𝑁𝑎3 𝑃𝑂4 (𝑎𝑞) →
aluminum nitrate (aq) + sodium phosphate (aq) → aluminum phosphate (s) + sodium nitrate (aq)
____𝐴𝑙(𝑁𝑂3 )3 (𝑎𝑞) + ____ 𝑁𝑎3 𝑃𝑂4 (𝑎𝑞) →
Neutralization
nitric acid (aq) + sodium hydroxide (aq) → sodium nitrate (aq) + water (l)
____𝐻𝑁𝑂3 (𝑎𝑞) + ____𝑁𝑎𝑂𝐻 (𝑎𝑞) →
sulfuric acid (aq) + sodium hydroxide (aq) → sodium sulfate (aq) + water (l)
____𝐻2 𝑆𝑂4 (𝑎𝑞) + ____𝑁𝑎𝑂𝐻 (𝑎𝑞) →
phosphoric acid (aq) + sodium hydroxide (aq) → sodium phosphate (aq) + water (l)
____𝐻3 𝑃𝑂4 (𝑎𝑞) + ____ 𝑁𝑎𝑂𝐻 (𝑎𝑞) →
Experiment 6 – Types of Reactions
Name __________________
Lab Section __________________
More reactions – Identify the type of reaction, predict the products, and balance.
____ 𝑃𝑏(𝑁𝑂3 )2 (𝑎𝑞) + ____𝐾𝐶𝑙 (𝑎𝑞) →
Type of reaction _______________
____𝐶𝑎 (𝑠) + ____𝑆 (𝑔) →
Type of reaction _______________
____𝐹𝑒𝐶𝑙3 (𝑎𝑞) + ____𝑀𝑔 (𝑠) →
Type of reaction _______________

____𝐶𝑎(𝐻𝐶𝑂3 )2 (𝑠) →
Type of reaction _______________
____𝐻3 𝑃𝑂4 (𝑎𝑞) + ____𝑀𝑔(𝑂𝐻)2 (𝑠) →
Type of reaction _______________
Determine whether the following are soluble or insoluble: (circle the correct answers)
Pbl2
K3PO4
BaCr2O7
Mg(OH)2
CaCO3
Fe2S3
Na2SO4
TiO2
NH4OH
CoCl2
HC2H3O2
CaSO4
Which of the following metal/solution pairings would react? (circle the correct answers)
Mg with AgNO3
Sn with HCl
Ca with PbNO3
K with LiC2H3O2
Fe with CaCl2
Hg with K2SO4
Fe with H2O
Au with H2SO4
Pb with ZnCl2
Zn with AlCl3
Ni with BaCl2
Cr with MgF2