Chapter 11 Notes
Honors Chemistry
Chapter 11: Chemical Reactions
Section 1 Notes – Describing Chemical Reactions
(Read pages 321-329)
Chemical Reactions are ALWAYS occurring!
 _______________ _______________ in your _______________ help _______________ food.
 _______________ use _______________ to grow by means of a _______________ process
called _______________.
 _______________ causes _______________ to _______________.
What is a chemical reaction?
 One or more _______________, called _______________ or _______________ change into one
or more _______________ substances, called _______________.
Reaction Equations
 Used to _______________ what happens in a _______________ _____________
 Written as _____________________________________________________ (Read as
_______________ _______________ ________________)
 Use _______________ signs for _______________ reactants or products
 Two forms:
o _______________ Equations
 Name of _______________ is expressed
o _______________ Equations
 _______________ _______________ are expressed
Consider the following:
 Iron reacts with air (oxygen) to form rust (Iron (III) oxide).
 Word Equation:

Chemical Equation:
Try it!
 When you light a burner on your stove, methane gas (CH4) bursts into flames when it reacts with
oyxgen in the air to produce water and carbon dioxide.
 Write both a word equation and a chemical equation for this reaction.
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Chapter 11 Notes
Honors Chemistry
More about Chemical Equations
 The _____________ equations that you have written so far are what’s called _____________
_____________
o _____________ Equation - _____________ equation that does _________ show the
_____________ amounts of _____________ and _____________
 _____________ equations are the _____________ for _____________ _____________
_____________ _____________ (We’ll get there shortly)
Symbols in Chemical Equations
 _____________ States
o (s) indicates a _____________
o (l) indicates a _____________
o (g) indicates a _____________
o (aq) indicates an _____________ _____________
 Example: O2 (g)
Different Arrows in Chemical Reactions

is the _____________ arrow, which means _____________

indicates that the reaction is _____________


indicates the use of a _____________, the _____________ for the
_____________ will appear _____________ the arrow
o Catalyst – a _____________ that _____________ _____________ the reaction, but is
_____________ used up in the reaction. It is not a _____________ or _____________
or
indicates that _____________ is used in the reaction
Practice Problems
1. Write a sentence that describes this chemical reaction.
Na(s) + H2O(l)  NaOH(aq) + H2(g)
2. Sulfur burns in oxygen to form sulfur dioxide. Write a skeleton equation for this chemical
reaction.
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Chapter 11 Notes
Honors Chemistry
Balancing Equations
 Imagine you are asked to write an equation to build a bicycle.
 Reactants: __________________________________________________________
 Product: Bicycle
 Is it enough to use the following equation:

First, express the final product in terms of the reactants:

Our new bicycle equation is:



Balancing equations means making the number of ____________ = ____________
So is our equation balanced?
Use _______________ to balance the equation.
o Coefficient: _______________ _______________ number placed in front of a
_______________ in an _______________ in order to _____________
Why do we balance equations?
 Law of _______________ of _______________
o States that _____________ cannot be ______________ or ______________
o What the reaction _______________ with, it must _______________ with
Let’s Try Balancing an Equation
Balance the following equation:
Al + Fe2O3  Al2O3 + Fe
Let’s Try Another One
Balance the following equation:
Zn(OH)2 + H3PO4  Zn3(PO4)2 + H2O
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Chapter 11 Notes
Honors Chemistry
Practice Problems
Balance the following equations:
1. ___ H2 + ___ O2 ___ H2O
2. ___ N2 + ___ H2 ___ NH3
3. ___ AgNO3 + ___ H2S → ___ Ag2S + ___HNO3
4. Hydrogen + Sulfur  Hydrogen Sulfide
5. Iron (III) Chloride + Calcium Hydroxide  Iron (III) Hydroxide + Calcium Chloride
6. Calcium Hydroxide + Sulfuric Acid  Calcium Sulfate + Water
7. ___ CS2 + ___ Cl2  ___ CCl4 + ___ S2Cl2
Book Work – Page 329 #7-12
Section 2 Notes – Types of Chemical Reactions
(Read pages 330-341)
Classifying Reactions
 Five Types
1. ______________________________
2. ______________________________
3. ______________________________
4. ______________________________
5. ______________________________
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Chapter 11 Notes
Honors Chemistry
Synthesis or Combination Reactions
 A _______________ change in which _______________ or more ______________ react to
form a _______________ _______________ substance
 Formula: ______________________________
 Can occur to form _______________ and _______________ compounds
 What’s important to remember: _______________ _______________
 Example:
Synthesis Examples
 Can be two _______________ combining to form a _______________:
o Sodium and chlorine react to form sodium chloride
o _____________________________________________________________
 Can be two _______________ combining to form a _______________.
o Sodium oxide combines with water to form sodium hydroxide.
o _____________________________________________________________
Synthesis Practice
1. Complete and balance this equation for a synthesis reaction:
___ Be + ___ O2  ___ BeO
2. Write and balance the equation for the formation of magnesium nitride (Mg3N2) from its
elements.
Decomposition Reactions
 A _______________ change in which a single _______________ _______________ down into
two or more _______________ _______________.
 Formula: ___________________________________________________________
 _______________ of _______________
 Most require _______________ in the form of _______________, _______________, or
_______________
 What’s important to remember: _______________ _______________
 Example:
Decomposition Practice
1. Balance the following decomposition reaction:
___ KClO3  ___ KCl + ___ O2
2. Complete and balance this decomposition reaction:
___ HI  ___ H2 + ___ I2
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Chapter 11 Notes
Honors Chemistry
3. Write the formula for the binary compound that decomposes to the products H2 and Br2.
Single Replacement Reactions
 A _______________ _______________ in which one _______________ _______________ a
second _______________ in a _______________.
 Essentially, the _______________ just _______________ places.
o _______________ replace _______________
o _______________ replace _______________
 Formula: ___________________________________________________________
 What’s important to remember: one _______________ and one _______________ on each side
of the _______________
 Example:
Activity Series
 Not all _______________ _______________ reactions will take place as written.
 _______________ _______________ - a list of _______________ in order of
_______________ _______________
 Some examples:
o Fe + CuO 
 _______________ occur – __________________________________
o Mg + LiCl 
 _______________ occur - __________________________________
o Ca + AgBr 
 _______________ occur - __________________________________
Single Replacement Practice
Complete the equations for these single-replacement reactions in aqueous solution. Balance each
equation. Write “no reaction” if a reaction does not occur. Use the activity series.
a. ___ Fe(3+) + ___ Pb(NO3)2 
b. ___ Ca + ___ Li2O 
c. ___ Zn + ___ H2SO4 
Double Replacement Reactions
 A chemical _______________ involving an _______________ of _______________
_______________ between two _______________.
 Essentially, two _______________ just _______________ places in two _______________.
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Chapter 11 Notes
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Honors Chemistry
Generally take place in _______________ solution and often produce a _______________,
_______________, or _______________ _______________
Formula: ___________________________________________________________
What’s important to remember: Two _______________ on each side
Example:
Double Replacement Practice
Complete and balance the equations for these double replacement reactions.
1. ___ NaOH + ___ Fe(NO3)3 
2. ___ Ba(NO3)2 + ___ H3PO4 
3. ___ H2SO4 + ___ Al(OH)3 
Combustion Reactions
 A chemical _______________ in which an _______________ or a _______________ reacts
with _______________, often producing _______________ in the form of _______________ or
_______________.
 _______________ involves _______________ as a _______________. The other
_______________ is usually a _______________ (compound containing _______________ and
_______________).
 _______________ combustion of a hydrocarbon (_______________ oxygen) yields
_______________ _______________ and _______________.
 _______________ combustion (_______________ oxygen) yields _______________
_______________
 Formula: ___________________________________________________________
 What’s important to remember: _______________ is a _______________
 Example:
Combustion Practice
Write a balanced equation for the complete combustion of each compound:
a. Formic acid (HCOOH)
b. Heptane (C7H16)
c. Glucose (C6H12O6)
Page 338-339 in your textbook is a good summary chart of the reaction types
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Chapter 11 Notes
Honors Chemistry
Practice Problems
Classify each of the following reactions as one of the chemical reaction types. Complete and balance
the equation for each as well.
1. ___ CH4 + ___ O2 
2. ___ K + ___ S  ___ K2S
3. ___ H2O ___ H2 + ___ O2
4. ___ Zn + ___ PbI2 
5. ___ CaBr2 + ___ AgNO3 
6. ___ Cu + ___ NaCl 
Book Work: Page 339 #22, 24, and 26
Section 3 Notes – Reactions in Aqueous Solutions
(Read pages 342-344)
Reaction in Aqueous Solutions…
 Just means _____________ that take place in _____________
Solubility of Ionic Compounds
 Some _____________ compounds are _____________ in _____________, which means they
will _____________, whereas others are _____________ in _____________, which means they
will _____________ _____________.
Solubility Rules
 Using the chart on your reference sheet, you can _____________ whether or not an
_____________ solid will _____________ in an _____________ _____________
 Try It!
o Decide whether the following ionic compounds are _____________ or _____________:
 LiOH _____________
 MgCl2 _____________
 NaNO3 _____________
 BaSO4 _____________
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Chapter 11 Notes
Honors Chemistry
Dissociation
 Remember that most _____________ compounds _____________, or _____________, in
_____________ _____________
 Technically when you _____________ salt (_____________ _____________ - NaCl) in water,
it doesn’t exist as ________, it exists as _____ ions and _____ ions
 Use this concept to write _____________ _____________ equations
o An _____________ that shows _____________ ionic compounds as _____________
_____________ _____________.
 Remember to check _____________ - _____________ compounds do not _____________
Complete Ionic Equation Example
 Predict the products for the following single replacement reaction:
AgNO3 + NaCl 

Now check the solubility and show the appropriate dissociations:

This is the complete ionic equation for the reaction.
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Chapter 11 Notes
Honors Chemistry
Net Ionic Equations
Ag+ + NO3- + Na+ + Cl-  AgCl + Na+ + NO3
_____________ ionic equations can be _____________ one step further – to a _____________
ionic equation
o An _____________ for a reaction in _____________ that shows _________ those
_____________ that are _____________ _____________ in the chemical
_____________
 Do you see any similarities on the reactant and product side of the reaction?
o These _____________ are called _____________ _____________
 _____________ that appear on _____________ sides of an _____________ and
are _____________ directly involved in the _____________.
 In this reaction, the _____________ ___________ are _________ and _________.
 _____________ ions in a reaction are _____________ because they don’t take part in the
_____________
 This makes our _____________ ionic equation: ____________________________
 Notice that the _____________ ionic equation is still _____________ in terms of
_____________ and _____________
Practice Problems
1. Write the balanced net ionic equation for this reaction:
Ca2+ + OH- + H+ + PO43-  Ca2+ + PO43- + H2O
2. Write the complete ionic equation and net ionic equation for the reaction of aqueous calcium
hydroxide with phosphoric acid. The products are calcium phosphate and water.
Book Work - Page 344 #30-35
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