Download 8 SHS Ch 8 Lecture shs_ch_8_lecture_2012

MOLECULAR FORMULA B24W8 MM 56
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EMPIRICAL FORMULA B3W1 MM 7
The main
tasks of Chap
Balance
Equations—easiest
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Balancing equations
CH4 + O2 → CO2 + 2 H2 O
A + sign shows that the compounds combine
form the products on the right of the arrow.
The arrow is read as “reacts to yield”
Example
Classify Equations—easy
Methane and oxygen = Combustion
Predicting reactions from word problems –
challenging
C (s) + O2 (g) CO2 (g)
Carbon (solid) reacts with diatomic oxygen (gas) to yield carbon dioxide (gas)
Methane + Oxygen →
Total Ionic Equations--challenging
+
-
+
-
Ag (aq) + NO 3 (aq) + Na (aq) + Cl (aq )
-
+
AgCl (s) + NO3 (aq) + Na (aq)
When balancing a chemical reaction you may
An equation is balanced when total number
of atoms of each element occur
1. the same number of times
2. on both sides of the equation.
Law of conservation of mass.
add coefficients in front of the compounds to
balance the reaction,
you may not change the subscripts.
Changing the subscripts changes the compound.
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Symbols of Conditions
Solid (s)
gas (g)
Liquid (l )
Aqueous solution (aq)
Change of temperature (∆)
Produces, Yields (
)
Reversible Reaction (
)
Compound above arrow: catalyst
4 basic steps to balancing
A coefficient in front of a formula multiplies
everything in the formula by that number.
2H2O
1.
Write the unbalanced formula
2.
Count up atoms on both sides
3.
Pick an unequal element and increase
the coefficient on the smaller side
4.
Repeat step 3 until all atoms are equal
on each side of equation
4NaOH
4 Al(s) + 3 O2(g) --->
--->
Al2O3(s)
4 Al(s) + 3 O2(g)
---> 2 Al2O3(s)
This equation means
4 Al atoms + 3 O2 molecules
---produces--->
2 molecules of Al2O3
AND/OR
4 moles of Al + 3 moles of O2
---produces--->
2 moles of Al2O3
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Write and balance the chemical equation :
Carbon Tetrahydride gas (methane) reacts with oxygen gas
To yield carbon dioxide gas and liquid water
1) What are the formulas of the reactants and products?
Balancing Trick
Do Carbon and Others First
Do Hydrogen
Do Oxygen last
REACTANT
PRODUCT
Methane: CH4
Carbon dioxide: CO2
Oxygen gas: O2 Water: H2 O
2) Write the general formula of the reaction
CH4(g) + O2 (g) → CO2 (g) + H2O(l)
CH4 (g) + O2 (g) → CO2 (g) + H2 O(l)
CH4 (l) + O2 (g) → CO2 (g) + H2 O(l)
Count the number of each element on both sides
For H: What number do you multiply the 2 H on the product by
to equal 4 Hs on the reactant side?
2
CH4 (g) + O2 (g) → CO2 (g) + 2 H2 O(l)
ELEMENT
REACTANT
PRODUCT
C
H
1
4
1
2
So now there are 4 H’s on both sides
Now there are 2 O on the reactant side and 4 O on the product side
O
2
3
For O: what number do you multiply the 2O on the reactant
side to get 4O?
2
C is balanced H is off by 2 and O is off by 1
CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2 O(l)
ELEMENT
REACTANT
PRODUCT
C
1
1
H
4
4
O
4
4
Reaction is balanced
CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2 O(l)
An iron bar rusts. The solid Iron reacts with
Oxygen gas (in the air) to make Iron (III) Oxide (rust).
If O xy gen is diatomic, What w ill be the ionically bonded formula
Fe
3+
+ (O
2) = 3+ 2-
Fe(s) + O2 (g) → Fe2O3 (s)
3
Fe(s) +
O2 (g) →
Fe(s) + O2 (g) → Fe2 O3 (s)
Fe2O3 (s)
For Fe: What number do you multiply the Fe on the reactant side
to equal 2 Fe on the product side?
2
Count the number of each element on both sides
ELEMENT
REACTANT
PRODUCT
Fe
O
1
2
2
3
2Fe(s) + O2 (g) → Fe2 O3 (s)
So now there are 2 Fe on both sides
Now there are 2 O on the reactant side and
3 O on the product side
For O: what number do you multiply the 2 O
on the reactant side to get 3 O?
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Fe is off by 1 and O is off by 1
2Fe(s) + 3O2 (g) → Fe2 O3 (s)
HOMEWORK ANSWERS
2Fe(s) + 3O2 (g) → Fe2 O3 (s)
For O: what number do you multiply the 3O on the
Product side to equal 6O on reactant side? 2
For Fe: what number do you change the 2Fe on the
Reactant side to get 4Fe on the product side? 4
4Fe(s) + 3O2 (g) → 2Fe2 O3 (s)
ELEMENT
REACTANT
PRODUCT
Fe
4
4
O
6
6
2
Reaction is balanced
Balance these skeleton equations:
Balance these skeleton equations:
a)
b)
Mg + HCl → MgCl2 + H2
Ca + N2 → Ca3N2
a)
b)
Mg + 2HCl → MgCl2 + H2
3Ca + N2 → Ca3N2
c)
d)
e)
f)
NH4NO3 → N2O + H2O
BiCl3 + H2S → Bi2S3 + HCl
C4H10 + O2 → CO2 + H2O
O2 + C6H12O6 → CO2 + H2O
c)
d)
e)
f)
NH4NO3 → N2O + 2H2O
2BiCl3 + 3H2S → Bi2S3 + 6HCl
2C4H10 + 13O2 → 8CO2 + 10H2O
6O2 + C6H12O6 → 6CO2 + 6H2O
g)
h)
i)
NO2 + H2O → HNO3 + NO
Cr 2(SO4) 3+ NaOH → Cr(OH) 3+ Na2SO4
Al4C3 + H2O → CH4 + Al(OH) 3
g)
h)
i)
3NO2 + H2O → 2HNO3 + NO
Cr 2(SO4) 3+ 6NaOH → 2Cr(OH) 3+ 3Na2SO4
Al4C3 + 12H2O → 3CH4 + 4Al(OH) 3
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Lead (II) Nitrate liquid dissociates when heated to yield
Lead (II) Oxide solid, Nitrogen Dioxide gas and Oxygen
gas.
Pb(NO3)2
→ PbO
(l )
(s) +
NO2
( g)
+ O2
Silver Nitrate and Iron (III) Chloride undergo a double
displacement reaction.
Predict the products and balance the equation.
( g)
AgNO3 + FeCl3 →
2Pb(NO3)2
AgCl + Fe(NO3)3
→ 2PbO(s) + 4NO2(g) + O2(g)
(l )
3AgNO3 + FeCl3 → 3AgCl + Fe(NO3)3
Types of Reactions
There are 6 types of chemical reactions we will talk about:
1.
2.
3.
4.
5.
6.
Combustion reactions
Synthesis reactions
Decomposition reactions
Single Displacement reactions
Double Displacement reactions
Acid Base Reactions (Not In Book)
You need to be able to identify the type of reaction study
page 284
Combustion Reactions
• In general:
CxH y + O2 CO2 + H 2O
• Products in combustion are ALWAYS carbon
dioxide and water. (although inTotal burning
does cause some by-products like carbon
monoxide)
• Combustion is used to heat homes and run
automobiles (octane, as in gasoline, is C8H 18)
Balance the chemical equation for combustion of pentane
1. Combustion Reactions
Combustion reactions occur
when a hydrocarbon reacts with
oxygen gas.
This is also called burning!!! In
order to burn something you
need the 3 things in the “fire
triangle”:
1) A Fuel (hydrocarbon)
2) Oxygen to sustain burn
3) Something to start the reaction
(spark) (AKA a catalyst)
Example balancing chemical equations
Step 1 . Insert 1 in front of the most complicated looking chemical
compound.
1 C 5H12 + O2 --> CO2 + H 2O
Step 2 . To balance C's, 5 must be inserted in front of C O 2.
1 C 5H12 + O2 --> 5CO2 + H 2O
Step 3 . To balance H 's, 6 must be inserted in front of H 2O .
1 C 5H12 + O2 --> 5CO2 + 6 H2O
Step 4 . To balance O's, 8 must be inserted in front of O 2 .
1 C 5H12 + 8O2 = 5CO2 + 6H2O
E rase 1 from the equation:
C 5H 12 + 8O2 = 5CO2 + 6H2O
5
2
The Videos that play with this are found in
TheSPEAR (transfer file) 1_24\SHS CHEM\STADIUM
CHEM\DEMO Chemystery\Demos Not Used\Chem
Comes alive
Combustion Reactions
Example:
The Combustion of Pentane C5H12
C 5H12 + 8 O2 Combustion Reactions
The Combustion of Pentyne C5H10
2 C 5H10 + 15 O2 10
5 CO2 +10
5
H2O
5 CO2 + 6 H2O
F or O : w hat number do y ou multiply the 15 on the product
side to get and even number ( odd even technique)?
A n ev en x odd w ill alw ays be even an odd x ev en = even
S o multiply the ev en (2) by 15 and the odd (15) x2 and the.
C heck y our table to see that all are balanced.
F or C and H : G o back and balance C and H . As Long as O does
N ot C hange it w ill be balanced as w ell.
C heck y our table to see that all are balanced.
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Combustion Reactions
The Combustion of Propane C3H8
C 3H8 +5 O2
3 CO2 +
2. Synthesis Reactions
• Synthesis reactions occur when two substances (generally
elements) combine and form a compound.
4 H2O
reactant + reactant 1 product
• Basically: A + B AB
•
•
Example:2 H2 + O2 2 H2O
Example: C + O2 CO2
C heck y our table to see that all are balanced.
Decomposition Reactions
Decomposition Reactions
C + O2
2 H2 + O2
CO2
2 H2O
2 C + O2
Synthesis
Reactions
Solid Potassium reacts with chlorine gas to form solid
2 CO
Synthesis Reactions
potassium chloride salt.
2 K (s) + Cl2 (g) 2 KCl (s)
Reaction of Sulfur + Copper(II)
S(s) +
Cu(s) CuS(s)
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Synthesis Reactions
JOD The last words of a chemist:
1. First the acid, then the water...
2. And now the detonating gas problem.
3. This is a Totally safe experimental setup.
4. Where did I put my gloves?
5. Oh no, wrong beaker...
6. The fire alarm is just being tested.
7. Now you can take the safety glass away...
8. I can just feel it how long 45 seconds are!
9. Something is wrong here...
10.. Trust me - I know what I am doing.
Reaction of Aluminum + Bromine
2 Al(s) + 3 Br 2(l) 2 AlBr 3(s)
Synthesis Reactions
JOD
What type of math does the chemistry owl like to use
for balancing formulas?
Owlgebra
N2 + 4 H2 2 NH4
3. Decomposition Reactions
• Decomposition reactions occur when a compound
•
•
•
Synthesize Nitrogen Tetrahydride
Decomposition
Reactions
Another view of a decomposition reaction:
breaks up into simpler structures
Reactant Product + Product
AB A + B
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Decomposition Reactions
Decomposition Reactions
2 NI3 2 HgO 2Hg + O2
Decomposition Reactions
N2 + 3 I2
4. Single Displacement Reactions
• Single Displacement Reactions occur when one element
replaces another in a compound.
A metal can replace a metal (+) OR a nonmetal can
replace a nonmetal (-).
• element + compound
product + product
•
2 H2O 2 H2 + O2
A + BC AC + B (if A & B are metals) OR
D + BC BD + C (if D& C are nonmetals)
(remember the cation always goes first!)
Single Displacement Reactions
Another view:
Single Displacement Reactions
Li
Sodium chloride solid reacts with fluorine gas SDR
2 NaCl(s) + F2(g) 2 NaF(s) + Cl2(g)
Aluminum metal reacts with aqueous copper (II) nitrate SDR
2 Al(s) + 3 Cu(NO3)2(aq) 3 Cu(s) +2 Al(NO3)3(aq)
H
Lithium metal reacts with Calcium Oxide SDR
2 Li(s) +
CaO(s) Li2O(s) + Ca(s)
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Activity Series
The activity series for predicting the products of Metal
Displacement (and nonmetal) reactions.
Single Replacement Rxns
To determine if a Single Replacement Reaction really
happens, use the ACTIVITY SERIES reference
sheet.
If an element is higher on the chart, it will become a
compound.
If the higher element is already in a compound, then
NO reaction occurs
Most activ e (most strongly
reducing) metals appear on
top, least activ e metals
appear on the bottom.
Li
K
Ca
Na
Mg
displace H2 from acids only
can't displace H2
KOH(aq) + H2(g)
Ca(s) + 2 H2O()
Ca(OH)2(s) + H2(g)
Al
2 Na(s) + 2 H2O()
Mn
2 NaOH(aq) + H2(g)
2O(g)
Zn
displace H2 from steam or acids
2 Li(s) + 2 H2O()
2 LiOH(aq)
2 K(s)
+ H2(g)
+ 2 H2O() 2
Fe
Ni
Li
Mg(s) + 2 H
2 Al(s) + +6H2(g)
Mg(OH)2(s)
H2O(g) 2 Al(OH)3(s) +
Mn(s) + 2 H2O(g)
The nonmetal activity series. Most active (most strongly
oxidizing) nonmetals appear on top, and least active
nonmetals appear on the bottom.
Cl2
O2
Mn(OH)2(s) + H2(g)
2O(g)
Zn(s) + 2 H
Br2
Pb
Zn(OH)2(s) + H2(g)
2O(g)
I2
H2
Fe(OH)2(s)
Ni(s)
+ 2+ H2(g)
H+(aq)
Cu
2+
Ni (aq) + H2(g)
Ag
Sn(s) + 2 H+(aq)
Pt
2+
Sn (aq) + H2(g)
+
Au
2Cu+Mg(NO 3) 2
Strongest
oxidizing
agent
F2
Sn
Ag + H2O NO RXN
Fe(s) + 2 H
H
Pb(s) + 2 H
weakest
oxidizing
agent
S
(aq)
2+
Pb (aq) + H2(g)
2HCl + F2 2HF + Cl2
Ag + H2O NO RXN
2Al + MnO Mn + Al2O3 KBr + O2 K2O + Br2
Cu + H2O NO RXN
Au + CaO NO RXN
Metals with lower ionization energies and lower
Electronegativity are more active, they lose electrons
more easily.
3 H2(g)
E xamples of Reactions That Don’t Work, or Work
Mg + 2CuNO 3
A strip of copper placed into a zinc sulfate will not react
Single Displacement Reactions
Does Carbon Dioxide solid react with Mg?
2 Mg + CO2 →
2 MgO + C
Shortcut to MAGCO2.lnk
Ag + SnO NO RXN
10
If X- ends in -ide --- acid name becomes HydroX-ic acid
HC l
HBr
HF
Hydrobromic
Hydrochloric
Acid
ACID REVIEW
HydroFlouric
Acid
Acid
2. if X- ends in -ate --- acid name becomes
acid ( No Hydro-)
HNO3
H2SO 4
HC lO 3
Nitric
Sulfuric
3. if X- ends
Acidin -ite --- acid
Acidname becomes
ous acid
HNO 2
H2SO 3
HC l02
Nitrous
Acid
Sulfurous
Acid
X-ic
Chloric
Acid X-
Chlorous
Acid
ACID NAMING RACE
12)HNO2
Phosphoric Acid
Chlorous Acid
Nitrous Acid
13)HC2H3O2
15)H3PO3
Acetic Acid
Phosphorous Acid
16)H2CrO4
17)HCO3
Chromic Acid
Carbonic Acid
Hydrosulfic Acid
11)H3PO4
12)HClO2
18) H2S
19) HNO3
20) HI
Single Displacement Reactions
Sodium SDR with Hydrochloric Acid
2 Na + 2 HCl 2 NaCl + H2
Nitric Acid
Hydroiotic Acid
Single Displacement Reactions
Potassium reacts with nitric acid SDR
2 K + 2 HNO3 2 KNO3 + H2
4. Double Displacement Reactions
• Double Displacement Reactions occur when a metal
replaces a metal in a compound and a nonmetal replaces a
nonmetal in a compound
• Compound + compound product + product
AB + CD AD + CB
Zinc reacts with sulfuric acid SDR
Zn + H2SO4 Zn + H2SO4 ?
ZnSO4 + H2
11
Double Displacement Reactions
• Think about it like “foil” in algebra, first and last ions go
together + inside ions go together
• Example:
Double Displacement Reactions
Reaction of Sodium Hydroxide + Cobalt (II) Chloride
2 NaOH (l) + CoCl2 (l) 2 NaCl + Co(OH)2
AgCl(s) + NaNO3(aq)
AgNO3(aq) + NaCl(aq) Shortcut to AGNONAOH.lnk
• Another example:
K2SO4(aq) + Ba(NO3)2(aq) 2 KNO 3(aq) + BaSO 4(s)
Double Displacement Reactions
Double Displacement Reactions
Reaction of Sodium Hydroxide + Silver Nitrate
Sodium Iodide with Mercury (II) Chloride
2 AgNO 3(aq) + 2 NaOH(aq) Ag2O(s) + 2 NaNO 3(aq)
+ H2O(l)
HgCl2(aq) + 2 NaI(aq) HgI2(s) + 2 NaCl(aq)
Shortcut to Sodium Iodide and HgCl.lnk
Shortcut to AGNONAOH.lnk
WHAT DO YOU NOTICE IN THESE REACTIONS
Single Replacement Rxns
To determine if the reaction occurs, use the
ACTIVITY SERIES.
Double Replacement Rxns
Two Ionic Compounds switch partners.
are mixed.
If the products are both aqueous ionic compounds,
then no reaction occurs.
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How to use Solubility Rules.
Soluble = dissolves in water=(aq)=aqueous
Insoluble= doesn’t dissolve in water = Solid
= (s) = cloudy = precipitate = ppt
C—
DR—Double
Combusion Replacement
AB
SR
SR
S
DR
SR
C
D
S
SR—Single
Replacement
S—Synthesis
D—Decomp
AB—Acid Base
HCl + NaOH → NaCl + H2O
ZnS + 2 HCl → ZnCl2 + H2S
2 HCl + Zn → ZnCl2 + H2
2 H2 + O2 → 2 H2O
3 Ca(OH)2 + 2 H3PO4 → Ca3(PO4)2 + 6 H2O
8 Al + 3 Fe3O4 → 4 Al2O3 + 9 Fe
C5H12 + 8 O2 → 5 CO 2 + 6 H2O
2 H2O2 → 2 H2O + O2
CaO + CO2 → CaCO3
Solubility Rules: see Table p 288
HOW DO WE KNOW (s)
In A queous Solution (AKA Water) :
A ll compounds of Group 1 and NH4+ are soluble.
A ll nitrates are soluble.
A ll halogens , except those of Ag+ and Pb 2 + are soluble.
A ll sulfates, except those of Group 2, Ag+, and Pb2+
ar e soluble.
A ll carbonates, except those of Group 1 and NH4+,
ar e soluble.
Write the compound formed from these ions:
Soluble or Not
CaCO3 NO
NH4Cl YES
PbBr2
NO
AgSO4 NO
CaNO3 YES
MgSO4 YES
Al(NO3)3 YES
Na2CO3 YES
K2O
YES
(NH4)2CO3 YES
ZnSO4
CaCl
CuNO3
MgCO3
CuSO4
MgNO3
K2CO3
AgCl
YES
YES
YES
NO
YES
YES
YES
NO
# Cations
Cation
# Anions
2
NH4
1
SO4
2
Fe 3 +
3
S2-
Fe2 S 3
1
Cu2 +
2
C2 H3 O2 -
Cu(C2 H3 O2 )2
+
Anion
2-
Formula
(NH4 )2 SO4
Determine the # of ions needed to make a neutral compound and then
write the formula:
# Cations
Cation
Anion
Formula
NH4 +
PO4 3 -
(NH4 )3 PO4
Ba 2 +
NO3 -
Ba(NO3 )2
Al
CO3 2 -
Al2 (CO3 )3
Sr 2+
OH-
Sr(OH)2
3+
# Anions
13
Use the Solubility Rules. Circle the compounds
below that would be precipitates (compounds that do
not dissolve in water):
Mixed Practice
State the type and balance the following reactions:
BaCl2 + H2SO4 BaSO4 + 2HCl
C6H12 + O2 6
CO
9
3. Zn + CuSO4 2 + 6 H2O
4.
Cs + Br2 ZnSO4 + Cu
5. 2FeCO3 2 CsBr
•
K2Cr2O7
Ag3PO4
K2Cr2O7
Ag3PO 4
Fe(NO3)3
CuOH
M gCO3
BaSO4
PbCl2
CaCl2
Fe(NO3)3
CuOH
MgCO 3
BaS O 4
PbCl 2
CaCl2
1.
2.
FeO + CO2
Net Ionic Equations
In a precipitation reaction a product of the
reaction is only slightly soluble, or insoluble.
This product is formed as a solid, also known as
a precipitate.
Solubility Rules can be used to determine if a
product is insoluble (forms a precipitate) p. 284
Sect 4 Net Ionic Equations
Three ways to write the same equation (usually with
double replacement rxns):
1. Total Molecular Equation
2. Total Ionic Equation
3. Net Ionic Equation
Ions in solution that are not used to form the
precipitate: spectator ions
Completing Equations
Also called “Predicting Products”
You have learned to recognize the
different types of reactions AND
How to Total them.
You need to remember:
Ion charges from the Periodic table (Ch 5) Writing Ionic
formulas correctly (Ch 5)
Acid names and formulas(Ch 5)
Polyatomic ions(Ch 5)
Diatomic elements (Lucky 7)
Water ionizes to make H+ and OHUse Activity series for single replacement
Use Solubility rules for double replacement
14
Synthesis Reactions
Making ONE PRODUCT.
Displacement Reactions
Also called Replacement reactions
Single Displacement/Replacement
Activity series used as a reference
Net Ionic Equations
1.Only the reactants and product taking part
in the precipitation are written in the
equation (the reactants as ions, the product
as a molecule.)
2. Spectator Ions are not included in the
equation
3.It is important to include the states of
matter in the chemical equation:
(s) for solid, the precipitate
(g) for gas (l) for liquid (aq) for substances
in aqueous solution
Decomposition Reactions
ONE REACTANT falls apart.
GOAL
Ability to to apply solubility rules to double
displacement reactions.
Net Ionic Equations
Equations for precipitation reactions (3):
Molecular Equations
All reactants and products are written as if
they are molecules
Ionic Equations
All reactants and products that are soluble
are written as ions, only the precipitate is
written as if it were a molecule
Net Ionic Equation
Written as for Ionic Equation except that
spectator ions are not included in the equation:
You have to write all three in net ionic
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Net Ionic Equations
AgNO3 (aq) + NaCl(aq)
Net Ionic Equations
AgCl(s) + NaNO3(aq)
AgNO3
NaCl
What happens when you put
AgNO3 and NaCl in water?
Net Ionic Equations
Net Ionic Equations
IONIC EQUATIONS
IONIC EQUATIONS
3
NaClAgNO
NaCl
NaCl AgNO3
3
NaCl AgNO
NaCl NaCl
AgNO
3
AgNO3 AgNO
AgNO
3 Na+ 3NaCl
+
Ag NO3
Cl-
NaClAgNO3 NaCl AgNO3
NaCl AgNONaCl
3
Na+ +ClAg+ NO3Ag
Cl
Na+
Na+ NO3
+
Ag NO3ClAgCl
Net Ionic Equations
Ionic Equations
IONIC EQUATIONS
AgNO3 (aq) + NaCl(aq)
+ NO 3NO3 Na
Na+ Na+ NO3 +
+
Na
NO3NO3 Na
+ NO Na+
Na
+
3
NO - NO3 Na+ Na
AgCl(s) + NaNO3(aq)
ionic equation
-
3
AgCl(s)
+
-
+
-
Ag (aq) + NO3 (aq) + Na (aq) + Cl (aq )
-
AgCl (s) + NO3 (aq) + Na+ (aq)
Ag + (aq) + Cl- (aq)
AgCl (s)
16
Total Molecular Eqn
Total Ionic Eqns
This is what we have been doing. Write the
Write the aqueous compounds as separate ions. Be
compounds with the ions together.
Example: NaCl (aq) + AgNO3 (aq)
Keep the solid(insoluble) ions or water molecules
AgCl (s) + NaNO3(aq)
sure to put the CHARGES ON THE IONS!
together.
Example:
Na+ (aq) + Cl- (aq) + Ag+(aq) + NO3- (aq)
AgCl (s) + Na+(aq)+ NO3-(aq)
Net Ionic Equations
Net
Equations
TakeIonic
the Total ionic
equations and remove any ion that is
aqueous on both sides. These ions are called Spectator
Ions.
OR
Find the Solid product or water, keep that part AND keep
the reactant ions that made the solid or water.
Ex:Ag+ (aq) + Cl- (aq)
AgCl(s)
AgCl(s)
Net Ionic Equations
1) Write the (balanced!) molecular equation first
- Reaction products: swap cations and anions
- Predict solubility (using S olubility rules)
Net Ionic Equations
AgNO3 (aq) + NaCl(aq)
AgCl(s) + NaNO3(aq)
2) Write the Total ionic equation next
- (s) compounds don’t ionize
- (aq) compounds do ionize
ion subscripts in the molecular equation become
coefficients in the Total ionic equation!
3) Write the net ionic equation next
- cancel spectator ions
The net ionic equation is just a “simplified” form
of the total ionic equation
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Net Ionic Equations
Net Ionic Equations
T he net ionic equation is constructed from the ionic equation:
Ag+ (aq) + NO 3- (aq) + Na+ (aq) + Cl- (aq)
AgCl (s) + NO3 - (aq) + Na+ (aq)
Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq)
AgCl (s) + NO 3- (aq) + Na + (aq)
Net Ionic Equations
Net Ionic Equations
Ag + (aq) + NO 3- (aq) + Na+ (aq) + Cl - (aq )
Ag+ (aq) + NO3 - (aq) + N a+ (aq) + Cl - (aq)
AgCl (s) + NO3- (aq) + Na + (aq)
AgCl (s) + NO3- (aq) + Na+ (aq)
Net Ionic Equations
Net Ionic Equations
No3- and Na+ are not participating in the reaction
+
+
-
+
-
+
-
Ag (aq) + NO 3 (aq) + Na (aq) + Cl (aq )
-
Ag (aq) + NO3 (aq) + Na (aq) + Cl (aq)
-
-
+
AgCl (s) + NO3 (aq) + Na (aq)
+
AgCl (s) + NO3 (aq) + Na (aq)
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Net Ionic Equations
+
-
+
Net Ionic Equations
Ag+ and Cl - are reacting to form
-
Ag (aq) + NO 3 (aq) + Na (aq) + Cl (aq )
+
-
+
AgCl (s) + NO3 (aq) + Na (aq)
-
+
-
Ag (aq) + NO 3 (aq) + Na (aq) + Cl (aq )
-
+
AgCl (s) + NO3 (aq) + Na (aq)
net ionic equation
net ionic equation
+
-
Ag (aq) + Cl (aq)
Ag+ (aq) + Cl- (aq)
Net Ionic Equations
Net Ionic Equations
Ag+ and Cl - are reacting to form
+
-
+
-
Ag (aq) + NO3 (aq) + Na (aq) + Cl (aq)
AgCl (s) +
NO3
+
-
+
-
Ag (aq) + NO 3 (aq) + Na (aq) + Cl (aq )
+
(aq) + Na (aq)
-
net ionic equation
Ag+ (aq) + Cl- (aq)
+
AgCl (s) + NO3 (aq) + Na (aq)
net ionic equation
+
-
Ag (aq) + Cl (aq)
AgCl (s)
Net Ionic Equations
net ionic equation
Ag+ (aq) + Cl- (aq)
AgCl (s)
Pb(NO 3)2 + 2NaI → PbI2 + 2NaNO 3
(aq)
(aq)
(s)
(aq)
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Net Ionic Equations
ANOTHER NET IONIC RXN
Lead (II) Nitrate + Sodium Iodide
Ba(NO3)2 (aq) + 2NiSO4 (aq) → BaSO4(s) +2 Ni(NO3)2(aq)
Ionic Equation
Barium Nitrate and Nickel (II) Sulfate
Ba(NO3)2 + NiSO4
Ba2+(aq) +
2NO3-(aq) + 2Ni2+(aq) + SO42-(aq)
BaSO4(s) + 2Ni+(aq) + 2NO3- (aq)
Cancel the “spectator ions” that appear on both sides of the arrow
Ba2+(aq) + 2NO3- (aq) + 2Ni2+(aq) + SO42+(aq) → BaSO4(s) + 2Ni2+(aq) +
2NO3- (aq)
“Net Ionic” Equation:
Pb2+(aq) + 2I-(aq) → PbI2(s)
Net Ionic Equation
Spectator Ion
Spectator Ion
Spectator Ion
Spectator Ion
Precipitate
Spectator Ions
Precipitate
Precipitate
Precipitat
e
Precipitate
Net Ionic Equations
Net Ionic Equations
Silver Nitrate + Potassium Dichromate
2AgNO3 (aq) + K2Cr2O7 (aq)
Ag2Cr2O7 (s) + 2KNO3(aq)
2Ag+ (aq) +2NO3-(aq) +2K+(aq) + Cr2O72- (aq)
Ag2Cr2O7 (s) +2K+ (aq)+2NO3-(aq)
2 Ag+ (aq) + Cr2O72-(aq)
Precipitate
Ag2Cr2O7(s)
Potassium and nitrate were the spectator ions
Copper(II) Sulfate + Sodium Hydroxide
CuSO4 (aq) + 2NaOH (aq)
Cu(OH)2(s) + Na2SO42(aq)
Cu2+ (aq) +SO42-(aq) + 2Na+ (aq) +2OH-(aq)
Cu(OH)2(s) + 2Na+(aq) +SO42-(aq)
Cu2+ (aq) + 2OH-(aq)
Cu(OH)2(s)
sodium and sulfate were the spectator ions
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Net Ionic Equations
Net Ionic Equations
Copper(II) Sulfate + Barium Nitrate
Cu(NO3)2 (aq) ) + BaSO4(s)
2-
2+
(aq) +SO 4 (aq) + Ba
Cu(NO3)2(aq) + Ag2SO42(s)
CuSO4 (aq) + 2AgNO3 (aq)
CuSO4 (aq) + Ba(NO3)2 (aq)
Cu2+
Copper(II) Sulfate + Silver Nitrate
-
(aq) +2NO 3 (aq)
Cu2+ (aq) +SO42-(aq) + 2Ag+ (aq) +2NO3-(aq)
Cu2+ (aq) +2(NO3) -(aq) + Ag2SO4(s)
BaSO4(s) + Cu2+ (aq) +2NO3-(aq)
Ba2+ (aq) + SO42- (aq)
BaSO4 (s)
copper(II) and nitrate were the spectator ions
Net Ionic Equations
Cu2+ (aq) + 2OH-(aq)
Silver and Nitrate were the spectator ions
Net Ionic Equations
Silver Nitrate + Sodium Hydroxide
AgNO3 (aq) + NaOH (aq)
Silver Nitrate + Potassium Chloride
AgOH (s) + NaNO3(aq)
AgNO3 (aq) + KCl (aq)
Ag+ (aq) +NO3-(aq) +Na+(aq) + OH- (aq) AgOH(s) +Na+ (aq)+NO3-(aq
Ag+ (aq) + OH-(aq)
AgOH(s)
Sodium and nitrate were the spectator ions
Net Ionic Equations
Barium Nitrate + Sodium Hydroxide
Ba(NO3)2 (aq) + 2NaOH (aq)
2Na(NO3) (aq) + Ba(OH)2 (s)
Ba2+ (aq) +2NO3-(aq) + 2Na+ (aq) +2OH-(aq)
+ 2Na+ (aq) +2NO3-(aq) + Ba(OH)2 (s)
Ba2+ (aq) + 2OH- (aq)
Cu(H)2(s)
AgCl (s) + KNO3(aq)
Ag+ (aq) +NO3-(aq) +K+(aq) + Cl- (aq)
AgCl (s) +K+ (aq)+NO3-(aq)
Ag+ (aq) + Cl-(aq)
AgCl(s)
Potassium and nitrate were the spectator ions
Acids and Bases( H+ and OH-) Rxn
(Actually a double displacement)
When acids (HA) and Bases (ZOH) mix, the H+ and
OH- combine to become H2O(l).
This is called a neutralization reaction.
The water H2O(l) stays together like insoluble solids. So
you keep it in the Net Ionic equation.
Ba(OH)2 (s)
Na and Nitrate were the spectator ions
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ACID BASE REACTIONS
Acid: A Hydrogen donor
ACID BASE REACTIONS
One example of an acid-base reaction is the reaction of
hydrobromic acid (HBr) with sodium hydroxide(NaOH):
Base: A Hydrogen acceptor
Ha + bOH --->
---> H2O + ba
HBr + NaOH ---> NaBr + H2O (l)
This is a special k ind of double displacement reaction that tak es
place when an acid and base react with each other. The H+ ion in
the acid reacts with the OH- ion in the base, causing the
formation of water. Generally, the product of this reaction is some
ionic salt and water.
REACTION REVIEW
1) Does your reaction have oxygen as one of it's reactants
and an carbon dioxide and water as products? If yes,
then it's a combustion reaction
2) Does your reaction have two (or more) chemicals
combining to form one chemical? If yes, then it's a
synthesis reaction
3) Does your reaction have one large molecule falling
apart to make several small ones? If yes, then it's a
decomposition reaction
4) Does your reaction have any molecules that contain only
one element? If yes, then it's a single
displacement reaction
REACTION REVIEW
5) Does your reaction have transfer of H + ion then it's an
acid-base reaction.
6) If you haven't answered "yes" to any of the questions
above, then you've got a double displacement reaction
HCl(aq) + NaOH(aq)
H2O(l) + NaCl(aq)
H+(aq) + Cl-(aq)+ Na+(aq)+OH- (aq)
H2O (l) Na+(aq)+Cl-(aq)
H+(aq) + -OH(aq)
H2O(l)
What is the Net Ionic Equation for
the reaction: HCl(aq) + NaOH(aq) ?
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Net Ionic Equations ACID BASE
Hydrosulfic Acid + Barium Hydroxide
H2S (aq) + Ba(OH)2 (aq)
BaS (aq) + 2H2O(l)
2H+ (aq) +S2-(aq) +Ba2+ (aq) + 2OH- (aq)
Ba (aq) + S (aq) +2H2O (l)
Barium and Sulfur were the spectator ions
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