The five general types of reaction are
combination, decomposition, singlereplacement, double-replacement, and
combustion.
A combination reaction is a chemical change in
which two or more substances react to form a single
new substance.
Magnesium + nitrogen yields magnesium nitride
Products:
 It will always just produce ONE product
 Group A metal and a nonmetal react, the compound is
the metal cation and the nonmetal anion
2K(s) +Cl2(g)
2KCl(s)
 When two nonmetals react in a combination reaction,
more than one product possible
S(s) + O2(g)
SO2(g)
2S(s) + 3O2(g)
2SO3(g)
 More than one product may also result from the
combination reaction of a transition metal and a
nonmetal
Fe(s) + S(s)
FeS(s)
2Fe(s) + 3S(s)
Fe2S3(s)
Complete and balance this equation for a
combination reaction.
Be + O2
Write and balance the equation for the
formation of magnesium nitride (Mg3N2)
from its elements.
A decomposition reaction is a chemical change in
which a single compound breaks down into two or
more simpler products.
Copper chloride decomposes to copper and chloride
Products:
 The products can be any combination of
elements and compounds.
 Usually difficult to predict.
 A simple binary compound will break
down to its constituents.
 Most decomposition reactions require
energy in the form of light, heat or
electricity
2HgO(s)
2Hg(l) + O2(g)
Complete and balance this
decomposition reaction
HI
Write the formula for the binary compound
that decomposes to the products H2 and
Br2
A single replacement reaction is a chemical
change in which one element replaces a
second element in a compound.
Magnesium replaces hydrogen in hydrochloric
acid to make magnesium chloride and
hydrogen gas
HCl
+
Mg
H2 + MgCl2
Whether one metal will displace another metal from a
compound depends upon the relative reactivities of the
two metals.
A reactive metal will replace any metal listed below it in
the activity series.
A halogen can replace another halogen from
a compound. The activity of the halogens
decrease as you go down.
Br2(aq) + NaI(aq)
Br2(aq) + NaCl(aq)
NaBr(aq) + I2(aq)
No Reaction
Complete the equations for these single
replacement reactions in aqueous solution.
Balance each equation. Put “no reaction” if a
reaction does not occur.
Fe(s) + Pb(NO3)2(aq)
Cl2(aq) + NaI(aq)
Ca(aq) + H2O(l)
A chemical change involving an exchange of
positive ions between two compounds.

One of the products is only slightly
soluble and precipitates from solution.

One of the products is a gas.

One product is a molecular compound
such as water.
Write the products of these doublereplacement reactions. Then balance each
equation.
NaOH(aq) + Fe(NO3)3(aq)
(Iron(III)hydroxide is a precipitate)
Ba(NO3)2(aq) + H3PO4(aq)
(Barium phosphate is a precipitate)
A combustion reaction is a chemical change in which
an element or a compound reacts with oxygen, often
producing energy in the form of heat and light.
2C8H18(l) + 25O2(g)
16CO2(g) + 18H2O(l)
The complete combustion of a hydrocarbon
produces carbon dioxide and water.
Write a balanced equation for the
complete combustion of each compound.
Formic acid (HCOOH)
Heptane (C7H16)