Synthesis Reactions
Two or more elements or compounds combine to
make a more complex substance
A + B  AB
H2 + O2  H2O2
Decomposition Reactions
Compounds break down into simpler substances
AB  A + B
2H2O  H2 + O2
Single Replacement Reaction
Occurs when one element replaces another one in a
compound
Also called Single displacement reaction
AB + C  AC + B
Fe+ HCl  FeCl + H
Double Replacement Reaction
Occurs when different atoms in two different
compounds trade places
Also called double displacement reaction
AB + CD  AD + CB
KCl + H2O  K2O4 + HCl
What type of reactions are these?
Reaction
Type
Cu + 2AgN3  CuN2 + 2Ag
Single Replacement
FeS + HCl  FeCl2 + H2S
Double Replacement
8 Fe + S8  8 FeS
Synthesis
2 KCl → 2 K + Cl2
Decomposition
NiCl2  Ni + Cl2
Decomposition
Zn + HCl  ZnCl + H2
Single Replacement
Can you do it all? (BON)
0 1. Iron (III) oxide plus water yields iron (III)
hydroxide.
0 2. In a displacement reaction, potassium hydroxide
reacts with hydrogen sulfate to produce dihydrogen
oxide and what?
What has to be done? How will you make certain the
Law of Conservation of Mass is followed? What type of
reactions are these?
Answers:
0 TO DO: Write the equation. Make sure the formulas are
correct. Balance the equation. Decide what type of equation it
is.
0 Fe2O3 + H2O  Fe (OH)
0
BAL: Fe2O3 + 3 H2O  2 Fe (OH)3
0 KOH + H2SO4 -> K2SO4 + HOH
0
BAL: 2KOH + H2SO4 -> K2SO4 + 2H2O