REACTIONS LAB
Section I

Combination Reactions
 Combination
reactions occur when two or more
substances come together to form a single, new
substance.
 A + B  AB
Reaction 1


Steel wool (iron with a +3 charge) combines with
oxygen.
Observations:
 Turned
blue
 Reduced mass to a gas

Complete balanced equation:
4Fe(s) + 3O2(g)  2Fe2O3(s)
Reaction 2


Copper wool (copper with a +1 charge) combines
with oxygen.
Observations:
 Flame
turned green
 Copper color changed to black

Complete balanced equation:
4Cu(s) + O2(g)  2Cu2O(s)
Reaction 3


Magnesium combines with oxygen.
Observations:
 Bright
white light
 Turned into a white powder

Complete balanced equation:
2Mg(s) + O2(g)  2MgO(s)
Reaction 4




Combination of calcium oxide and water.
What color were the contents of the test tube after
the indicator was added? Blue
Does this color indicate an acid or a base? Base
Complete balanced equation:
CaO(s) + H2O(l)  Ca(OH)2(aq)
can also be written as…
CaO(s) + HOH(l)  Ca(OH)2(aq)
Reaction 5


Combination of carbon dioxide and water.
Observations:
 Bubbles
being blown in water
 Color changed from blue to green to yellow

What acidic product can you predict for this
combination reaction?
 H2CO3

= carbonic acid
Complete balanced equation:
CO2(g) + H2O(l)  H2CO3(aq)
Section II

Decomposition
 Decomposition
reactions result as one substance breaks
down to two or more simpler substances.
 AB  A + B
Reaction 6


Hydrogen peroxide decomposition.
Observations:
 Bubbles
let off
 Splint was re-ignited

Write a complete balanced equation
MnO2
2H2O2(aq)  O2(g) + 2H2O(g)
Reaction 7


Sodium hydrogen carbonate decomposition.
Observations:
 Gas
being let out
 Condensation at mouth of test tube


Complete balanced equation:
2NaHCO3(s)  H2O(g) + CO2(g) + Na2CO3(s)
Section III

Single Replacement Reactions
 In
this reaction, one substance will replace another
substance in the compound.
 A + BC  AC + B
Reaction 8



Reaction of calcium and water.
Does the color indicate the presence of an acid or a
base? What is the product?
Observations:
 N/A

Complete balanced equation:
Ca(s) + 2H2O(l)  Ca(OH)2(aq) + H2(g)
Reaction 9


Reaction of zinc and hydrochloric acid
Observations:
 Bubbles/gas
 Zinc

dissolving
Complete balanced equation:
Zn(s) + 2HCl(aq)  ZnCl2(aq) + H2(g)
Reaction 10


Reaction of zinc and lead (II) nitrate.
Record your observations:
 Bubbles/gas
 Color

change (bright silver to dark silver)
Complete balanced equation:
Zn(s) + Pb(NO3)2(aq)  Zn(NO3)2(aq) + Pb(s)
Section IV

Double Replacement Reactions
 In
double replacement reactions, the substances are
dissolved in water and ionic in nature. This means that
when you mix the two substances, the ions are free to
move around and find another partner. If the
partnership results in a compound which is insoluble in
water, a precipitate (solid) will form. If a gas is formed,
you will see bubbles.
 AB + CD  AD + CB
Reaction 11


Sodium carbonate reacts with barium nitrate.
Observations:
 N/A

Complete balanced equation:
Na2CO3(aq) + Ba(NO3)2(aq)  2NaNO3(aq) + BaCO3(s)
Reaction 12


Lead (II) nitrate reacts with potassium iodide.
Observations:
A
solid is formed
 The color changes to yellow

Complete balanced equation:
Pb(NO3)2(aq) + 2KI(aq)  PbI2(s) + 2KNO3(aq)
Reaction 13


Sodium hydrogen carbonate reacts with hydrochloric
acid.
Observations:
Foaming
 Bubbles



Complete balanced equation:
NaHCO3(s) + HCl(aq)  NaCl(aq) + H2CO3(aq)
Note the “acid” product in this reaction is unstable and
breaks down to form carbon dioxide and water.
H2CO3(aq)  H2O(l) + CO2(g)
Reaction 14


Calcium carbonate reacts with hydrochloric acid.
Observations:



N/A
Write a complete balanced equation for this reaction.
CaCO3(s) + 2HCl(aq)  CaCl2(aq) + H2CO3(aq)
Note the “acid” product in this reaction is unstable and
breaks down to form carbon dioxide and water.
H2CO3(aq)  H2O(l) + CO2(g)
Section V

Combustion of Hydrocarbon
 When
a compound composed of carbon and hydrogen
burns in the presence of oxygen, carbon dioxide and
water are produced.
 Hydrocarbon + O2  CO2 + H2O
Reaction 15


The combustion of methane.
Description of the flame:
 Blue
 Inner

cone and outer cone
Complete balanced equation:
CH4(g) + 2O2(g)  CO2(g) + 2H2O(g)
Reaction 16


The combustion of ethanol.
Observations:
 N/A

Write a complete balanced equation for this
reaction.
C2H5OH(l) + 3O2(g)  2CO2(g) + 3H2O(g)