Warm Up


Watch the Demo of Copper with Nitric Acid.
List several evidences for chemical reaction.
Chemical reactions are
everywhere!

Chemical
Reactions: the
process by which
the atoms of one or
more substances
are rearranged to
form different
substances.
Atoms
are rearranged
during the flash of lightning!
Chemical Equations
Reactants  Products
Reactants: starting substances
Products: substances formed during the
reaction
*Shows the direction in which the
reaction progresses.
*  means “yield” or “react to produce”
Chemical Equations
Symbols are used to show the physical
states: solid(s), liquid(l), gas(g).
“aqueous” (aq) substance is dissolved in
water

The Language of Chemistry
Write the chemical equation that corresponds to
the following reactions
Example
1. Solid calcium oxide reacts with water and
yields calcium hydroxide solution.
2. Zinc metal reacts with a hydrogen sulfate
solution to produce a zinc sulfate solution
and hydrogen gas.
3. A potassium bromide solution reacts with
chlorine gas to produce a potassium
chloride solution and bromine gas.
Warm Up


Write a balanced chemical equation for
the following demo.
Isopropyl alcohol (CH3)2CHOH when
ignited (Oxygen gas) combusts to form
Carbon dioxide gas and water.
Observing and Predicting Reactions

How do we know whether a reaction
occurs? What clues does nature offer?
Make a list.
What clues does nature offer that a
chemical reaction occurred?
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
ppt
crystal
color
gas
fumes
smoke
temperature
flames
magnetic
sound
light
solid decomp
explosion
solid dissol.
odor
elect. cond.
pH change
density
electricity
Moving On
Go to next topic
Precipitate Formation
Ag+ + Cl-  AgCl
Cr3+ + 3OH-  Cr(OH)3
Ba2+ + CrO42-  BaCrO4
return
Solid Decomposition
(NH4)2Cr2O7(s)  Cr2O3(s) + 4H2O(g) + N2(g)
CuSO4.5H2O 
CuSO4 + 5H2O(g)
2NI3
 N2 + 3I2
return
Gas Bubbles
Ca + 2H2O  Ca(OH)2 + H2(g)
Cr + 2H+  Cr2+ + H2(g)
Mg + 2HCl 
MgCl2 + H2
return
Fumes/Gas Formation
Cu + 4HNO3  Cu(NO3)2 + 2NO2 + 2H2O
2H2O2  2H2O + O2
Zn + I2  ZnI2
return
Smoke
2Al + 3Br2  2AlBr3
2Na + Cl2  2NaCl
P4 + 5O2  P4O10
return
Flames
2Na + Cl2  2NaCl
2CrO3 + 3C2H5OH 
Cr2O3 + 3CH3CHO + 3H2O
return
Light
2Fe + 3O2  Fe2O3
2CH3OH + O2 2CO2 + 4H2O
2H2 + O2  2H2O
return
Temperature Change
Ba(OH)2.8H2O + NH4Cl
Thermite: Al + Fe2O3
return
Color Change
Cl2 + 2I-  2Cl- + I2
Cu + 4HNO3 
Cu(NO3)2 + 2NO2 + 2H2O
return
Crystal Formation/Solid Deposition
Cu + 2Ag+  Cu2+ + 2Ag
Zn + Sn2+  Zn2+ + Sn
return
Solid Dissolution
Mg(OH)2 + 2HCl  MgCl2 + 2H2O
AgCl(s) + 2NH3(aq) 
Ag(NH3)2+ + Cl-
return
Sound
Oxidation of sugar
Fireworks
return
Explosion
Dynamite
Building Demolition
Whale Removal
return
Odor
Certain molecules, especially those
containing sulfur or nitrogen,
have distinctive odors.
return
Electrical Conductivity
Ba(OH)2 + H2SO4
return
Density/Volume
Sugar + H2SO4
return
pH Change
return
Magnetic Properties
Fe + S8
return
Generate Electricity

Chemical
reaction
in the
battery
return
Lab- How do we know what
gas is being produced?



Demo- Gas Collection by Water
Displacement
Minimum of two trials of each reaction
Work as pairs within your groups

While others are testing draw apparatus
and write the general procedures
Lab- How do we know what
gas is being produced?

Experiment 1
Zinc metal reacts with hydrochloric acid to
produce hydrogen gas and zinc (II)
chloride.

Experiment 2
Dihydrogen dioxide in the presence of the
catalyst sodium iodide decomposes to
produce oxygen gas and liquid water.
Lab- How do we know what
gas is being produced?
Experiment 3
Calcium Carbonate reacts with hydrochloric acid to produce a
gas. What gas is it?


Design an experiment to identify the gas produced.
Include predictions. Get it signed off before you
begin
If…and…then…


If(hypothesis) and(test) then(prediction)
If all chemistry students have memorized the element
names and symbols and they are asked to the name or
symbol for any element then every student will answer
every question correctly.
Lab- How do we know what
gas is being produced?


What did you learn from Experiment 3?
What gas is being produced?
Lab- How do we know what
gas is being produced?
Experiment 4
Can we confirm this some other way?

Group Quiz
1.
2.
3.
4.
Hydrogen gas reacts with oxygen gas to
produce water
Carbon monoxide gas reacts with oxygen
gas to yield carbon dioxide gas.
Liquid dihydrogen dioxide decomposes to
produce water and oxygen gas.
A calcium hydroxide solution reacts with a
hydrogen sulfate solution to produce a
calcium sulfate solution and water.
What do all Chemical Reactions
have in Common?
All Chemical Reactions obey the
Law of Conservation of Matter
Nothing can be created or destroyed.
(What goes in must come out.)
4 main types of chemical
reactions
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Synthesis or Combination
Decomposition
Single Displacement
Double Displacement
Types of Chemical Reactions
Combination reaction
•
•
A + B  AB
Ex. metal + oxygen  metal oxide

2 Mg (s) + O2 (g)
2 MgO (s)
Decomposition Reaction
AB  A + B
Ex. salt  metal + nonmetal
2 NaCl (s)  2 Na (s) + Cl2 (g)

Single-Displacement Reaction
A + BC  B + AC or A + BC  C + BA
Ex. metal + acid  hydrogen + salt
•
Zn (s) + 2 HCl (aq)  H2 (g) + ZnCl2 (aq)
Ex. metal + salt  metal + salt
•
Fe (s) + CuSO4 (aq)  Cu (s) + FeSO4 (aq)
•
Double-Displacement Reaction
AB + CD  AD + CB
Ex. acid + base  salt + water
•
HCl (aq) + NaOH (aq)  NaCl (aq) + H2O (l)
Can you Classify the following
picture reactions?
1
2
3
4
4 Types of Reactions
Synthesis
Decomposition
Single
Displacement
Double
Displacement
Some Practice
Write as many chemical reactions as you can think of
using the following atoms and molecules as reactants.
Practice

Word Equations and reaction types
identification
Classification of Chemical
reactions

Individual


Classify each type of reaction
Group Quiz

Work as a group to write word equations
for each of the reactions
Classification of Chemical
Reactions
Examples
1. 2H2 + O2  2H2O
Hydrogen reacts with oxygen to
produce water.
2. 2H2O  2H2 + O2
Water decomposes to produce
hydrogen and oxygen
Balancing Equations


Coefficient – the whole number out
front of the formula- tells you how many
of each molecule
Subscript – small number to the bottom
right of an element- tells you how many
atoms of that element are in the
molecule.
Balancing Chemical Equations
1.
2.
3.
4.
Write a formula equation with correct
symbols and formulas.
Count the number of atoms of each
element on each side of the arrow.
Balance atoms by using coefficients.
Check your work by counting atoms
of each element.
Balancing Chemical Equations
Practice Problems
 Sodium hydroxide decomposes to
produce sodium oxide and water.

Iron reacts with oxygen to produce
iron(III) oxide.
Round Table – Balancing
Chemical Equations
1.
2.
Balance the Equation
Write a complete sentence for each
reaction including (atom/molecule)
references to the coefficients.
Team

Iron can be obtained by reacting the
naturally occurring ore hematite, Fe2O3,
with carbon. The carbon is converted
to CO2. Write a balanced chemical
equation for this reaction.
Helpful info
Sulfuric Acid- H2SO4
Ammonia- NH3
Carbonic Acid - H2CO3
Hydrofluoric Acid – HF
Phosphoric Acid – H3PO4
Law of Conservation of Mass

Balancing synthesis and Decomposition
Reactions


Counting atom
amu– atomic mass unit
Predicting Products
Identify the type of reaction
 Write the products of the reaction
 Balance the equation
Example.
1. Cl2 + KI
2. FeCl3 + NaOH 

Single Displacement: Cu + AgNO3
Lab – Types of Reactions
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9 experiments
Work at an open station
Demo Copper and Silver Nitrate
Predicting Products
Being able to write a chemical equation
does not necessarily mean that the
reaction will take place.
There is a way to predict whether a
reaction will occur and what the
products will be.
The Activity Series of Metals
Predicting Products
The Activity Series
Matter tends to react in
such a way that more
reactive substances
form less reactive
substances.
 Activity series: a list of
metals organized
according to their
tendency to react.
Activity Series


The higher the metal
on the activity series,
the more active that
metal.
The more active
elements tend to be
more stable in a
compound than in
elemental form
Predict whether a reaction
occurs
Practice


Pb + MgCl2
Al + Cu(NO3)2
Group Quiz

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
Na + H2O
Ca + Fe(NO3)2
Ag + Mg(NO3)2
Zn + Cu(NO3)2
Objectives
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
Students will review types of chemical
reactions.
Students will investigate the law of
conservation of matter and its effect on
chemical equations.
Students will learn to balance chemical
equations