Download Notes for Types of Reactions:

Topic # 4.1
GPS: 2b
Evidence & Types of Chemical Reactions
Date: _____/_____/_____
Part I: Describing Chemical Reactions
 chemical reaction = the _________ by which one or more substances are __________ into one
or more _________ substances.
 in any chemical reaction, the _________ substances are known as the reactants and the
__________ substances are known as the products.
total mass of reactants =
 according to the law of _______________ of ______:
total mass of products
 chemical reactions are described by __________ ___________.
 chemical equation = represents, with ________ and _________, the _________ and ______
amounts of the reactants and products in a chemical reaction. For example:
“The reactant __________ ___________ yields the products ________, _________ (___) ______,
and _______.” is the same as: (NH4)2Cr2O7(s)  N2(g) + Cr2O3(s) + H2O(g)
 the equation above is UNBALANCED. We will balance it using ____________ later.
Part II: Evidence of Chemical Reactions
 to know for certain that a reaction has taken place requires __________ that one or more
substances have undergone a _______ in ________.
1. Evolution of _____ and ______. A change in matter that releases _______ as both heat
and light is strong _________ that a chemical reaction has taken place.
2. Production of a ____. The evolution of ____ _______ when two substances are mixed is
often evidence of a chemical reaction.
 Ex: bubbles of ____ gas form immediately when _______ ____ is mixed with _______.
NaHCO3(s) + CH3COOH(l)  CO2(g) + NaC2H3O2(aq) + H2O(l)
3. Formation of a _________. Many reactions take place between
substances that are _________ in liquids. If a ______ appears after two
_________ are mixed, a reaction has likely occurred.
 precipitate = a _____ that is produced as a result of a chemical
reaction in ________ that __________ from the solution.
4. Color change. A _______ in color is often an indication of a chemical
reaction. Ex: _______ breaks down ____ molecules attached to ______, altering the
__________ of light they reflect, thus ________ the color.
5. Evolution of an odor. Odors that _________ ________ indicate new, ________ chemicals
have been produced.
Part III: Types of Chemical Reactions
 there are ___ distinct types of chemical reactions. Each has a _______ ________ that
represents the types of __________ that react within each type of reaction.
1. synthesis = combines ___ small compounds or atoms into
one _________ compound
 the “_________” reaction
 Ex: ____ + ____  _______
____ + ____  _______
A + X  AX
____ + ____  _______
2. decomposition = splits 1 compound into ___ or more _______
AX  A +
compounds or atoms
 the “________” reaction
 Ex: ______  ___ + ___
______  ___ + ___
______  ___ + ___
X
3. single replacement = _______ cation or _____ of a compound AX + B  BX
with another _____ cation or anion
AX + Y  AY
 the “___-________” reaction
 Ex: ______ +___  _______ + ___
______ +___  _______ + ___
______ +___  _______ + ___
+A
+X
______ +___  _______ + ___
Li
Rb
K
Ba
Sr
Ca
Na
Mg
Al
Mn
Zn
Cr
Fe
Cd
4. double replacement = the _______ of one compound is
AX + BY  AY + BX
combined with ______ of the other compound, creating 2
Co
____ compounds
Ni
 the “________ ________” reaction
Sn
 Ex: ______ + ______  ______ + _______ ______ + ______  ______ + ______ Pb
__________ + __________  __________ + ___________
5. combustion = _____________ + ___ produces
CnHn + O2  CO2 + H2O
____/___, ______, plus energy
 the “________ ____________” reaction (not ____ compounds)
 sometimes results in _____ as a product, other times ____
 Ex: ______ + ____  ______ + ______
______ + ____  ______ + _____
______ + ____  ______ + ______
______ + ____  ______ + _____
H2
Sb
Bi
Cu
Hg
Ag
Pt
Au
F2
 now let’s take a closer look at the ______-___________ reaction again...
Cl2
 the activity series helps determine whether or not one element can ________ another in a Br2
I2
______-_________ rxtn.
 if an element is ______ another, it can replace it. So, can these reactions happen or not?
 Ex: NaCl + K  KCl + Na  yes  no
NaCl + Br2  NaBr + Cl2  yes  no
Al2(CO3)3 + Li  Li2CO3 + Al  yes  no
Part IV: Symbols Found in Chemical Equations
 (s)
 (g)
(l)
(aq)

_____ ( for ____________)
___ ( for gaseous ________)
______
in _______ solution
_______ or produces
NaHCO3(s) + CH3COOH(l) 
CO2 + NaC2H3O2(aq) + H2O(l)


__________ reaction
_____ applied to reactants
2 atm specific ________ for rxtn
0°C
specific ______ for reaction
MnO2 ________ needed for rxtn
Part V: Other Info About Chemical Reactions
 Some elements occur only in ___________ form, meaning they are bonded to another ______
of that element. ___, ___, ___, ___, ___, ___, ___
 These gases are ______ found __ ____________ in any chemical _________ or _________!!!
 ________________ = ______ numbers __ ______ of a chemical formula
 ______________ = ______ numbers ________ a chemical formula
5Al2(SO4)3
4Na2S
2MgCl2