U9D4 Double Replacement

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Ion Exchange Reactions
Different Motivation = Different Results!
U9D4: Double Replacement Rxn
HW: see schedule; Type of Reaction cartoon
due tomorrow
Do Now: 1. HW out for check/answers
2. Complete Work Packet p. 6 A.
Be prepared to defend your answers
Today: 1. HW answers
2. Redox Check
3. Double Replacement Rxn notes
4. Practice
5. Will They Won’t They
Announcements
Unit 9 Practice test is online Testwizard.com
Class codes were sent home via SchoolTool
 Period 1: CCQF-ASIM-S3
 Period 2: CCQB-ASIM-R6
 Period 3: CCQN-ASIM-WQ
Quarterly Topic Sheet was sent home via SchoolTool
Chemthink.com is a great website for review
 Student code: 4679-7503-9706
Hwk #3) REDOX Reactions Homework
A) Multiple Choice Questions: Place your answer in the space in front of each
question.
C
_____1) In the reaction 2 Na + 2 HCl  2 NaCl + H2, which species is the spectator ion?
a) Na0
b) H+1
c) Cl-1
d) Na+1
Why is this the spectator ion? Explain, in terms of ion charge.
Cl- has the same ion charge as a reactant
and product.
It is not involved in the reaction.
A
_____2) In the reaction Zn + 2 HNO
a) Zn(NO3)2
A
b) (NO3)2Zn
3
 _________ + H2, the missing product is
c) ZnNO3
d) NO3Zn
_____3) In the reaction 2________  2 Pb + O2, the missing product is
a) PbO
b) OPb
c) PbO2
d) O2Pb
B) Identify the type of reaction shown: Use the key S for synthesis, D for
decomposition, SR for single replacement
Reaction
KBr + Na à NaBr + K
2 LiNO3 + Ca à Ca(NO3)2 + 2 Li
2 Fe + 3 Cl2 à 2 FeCl3
2 Li2O à 4 Li + O2
What
Type?
How Did You Know?
(Clue)
SR
SR
“May I cut in”
S
D
2 reactant 1 product
“May I cut in”
1 reactant 2 product
C) Write the charges of each species, then identify which species are oxidized,
reduced and spectator ions in the following reactions: (for polyatomic ions, use the
charge on the polyatomic ion)
+1 -2
0
0
1) Ag2S  2 Ag + S
-2
+1
S
Ag
none
OXIDIZED:________ Reduced:_________ Spectator Ion:____________
0
+1 -1
0
+1 -1
2) KBr + Na  Na Br + K
Na 0
K +1
-1
Br
OXIDIZED:___________ Reduced:____________ Spectator Ion:____________
+1 -1
0
+2
-1
0
3) 2 Li NO3 + Ca  Ca (NO3)2 + 2 Li
0
+1
-1
Ca
Li
NO3
OXIDIZED:___________ Reduced:____________ Spectator Ion:___________
0
0
+3 -1
4) 2 Fe + 3 Cl2  2 Fe Cl3
0
none
0
Cl2
Fe
OXIDIZED:__________ Reduced:____________ Spectator Ion:___________
+1 -2
0
0
5) 2 Li2 O  4 Li + O2
-2
+1
O
Li
none
OXIDIZED:__________ Reduced:____________ Spectator Ion:__________
D) Complete the following reactions by writing the appropriate formula(s)
(Remember BrINClHOF ‘s come in pairs when alone!)
NaBr
a) 2 Na + Br2 à2 __________
Cl2
b) Mg + ______________________
à MgCl2
O2
c) 2 BaO à 2 Ba + ___________
N2
d) 2 NO2 à _____________ + 2 O2
Li3N
e) 2 ______________à 6 Li +
N2
Cu
f) 2 Sc + 3 CuSO4 à Sc2(SO4)3 + 3 ___________________
KNO2
g) Cu + 2 _________________à Cu(NO2)2 + 2 K
Check : Write your answers on the white board
For your reaction:
1) assign the oxidation #s
2) Determine what is oxidized or reduced
3) Identify the spectator ion (write “none” if no spectator ion)
4) Identify the type of REDOX reaction:
___ A. 4Al + 3 FeO2  2 Al2O3 + 3 Fe
ox # __________ red# __________ spectator ion: _______
___ B.
Zn
+ 2 HCl 
ZnCl2
+
H2
ox # ________ red# _______ spectator ion: _______
Double Replacement Reactions
Relevant Vocabulary
 Soluble: able to be dissolved into a solvent
 Insoluble: Dissolves only to a small degree into a solvent
 Solute: the material whose IMAF are overcome by and breaks
up into a solvent.
 Solvent: the material into which a solute may be dissolved
 Precipitate: an insoluble product that exits the solution. In
terms of today, the precipitate will be a SOLID.
Ion Exchange (Double Replacement) Reactions
 Reactions in which two aqueous solutions are
mixed resulting in a solid precipitate.
 The cation of one solution and the anion of the
other solution attract so strongly that water
cannot break the ionic bond and the ionic
compound formed “falls out” of solution as a
solid precipitate.
AB (aq) + CD (aq)  AD (s) + CB (aq)
Solubility
 Use Reference Table F to determine solubility
 Soluble: can be used as a reactant in the reaction
 Insoluble: is the precipitate product of the reaction
Do Now Work packet p. 6A
A) Use TABLE F to determine if the following ionic compounds are soluble or
insoluble
1. Determine the cation and the anion in the compound given
2. Look up the anion on Reference Table F: it should fall in the soluble or
insoluble column
3. Determine if there are any exceptions to the rule that apply
a) Al(OH)3 _______
c) CaCl2 _______
b) (NH4)(NO3) _______ d) Mg(CO3) _______
Dissolving
Example Double Replacement Reaction
+1 -1
+1
-1
AgNO3 (aq) + NaCl (aq)  Ag Cl (s)
+ Na NO3 (aq)
AB
+
+ CD
Example Double Replacement Reaction
+1
+2
-1
-3
3 Ca(NO3)2 (aq) +2 K3PO4 (aq)  6 K NO3 (aq) + Ca 3 ( PO4 ) 2 (s)
AB
+ CD
+
Animation
Pb(NO3)2 (aq) + 2 KI (aq)  2 KNO3 (aq) + PbI2 (s)
Making A Desired Precipitate
+2
-1
+1
-2
+1
-1
Ca ( NO3)2 (aq) + K 2CO3 (aq)  2 K NO3 (aq) +
CaCO3 (s)
4)The
1)
Write
reactants
the formula
are two
of the
solutions,
productone
(made
containing
from the
the
+2
-2
2)
3)
5) Find
Balance
a +– ion
the that
reaction.
will be soluble with CO
Ca 3 . .
Ca+2 ion , the
spectator
ions).
other containing the CO3-2 ion.
Differences Between Redox Reactions and Ion
Exchange Reactions
REDOX
ION EXCHANGE
Charges of species
changes from one side to
the other
Spectator ion is the
species that does not
change charge from one
side to the other
Both take
reactants and
turn them into
products
Both require writing
formulas based on the
charges found on the
Periodic Table
Charges of species
do not change from one
side to the other
Spectator ion is the
species that remains in
solution from one side
to the other
Your turn…work packet p. 6B
B) With Reference Table F, predict the products and determine which is
the soluble (aq) and which is the insoluble (s) product.
a) CuCl2 (aq) + Na2(CO3) (aq)
b) 3 K2(CrO4) (aq)
s +
 CuCO3
__________ (___)
+ 2 Fe(NO3)3 (aq)
aq
2 NaCl (___)
__________
KNO3 (____)
aq +
 6_________
Fe2(CrO4)3
s
_________ (____)
NaNO3(____)
aq +
c) Na2(CO3) (aq)
+ 2 Ag(NO3) (aq)
 2_________
Ag2CO3
s
_________ (____)
KNO3 (____)
aq +
d) KCl (aq)
+ Ag(NO3) (aq)
 _________
AgCl (____)
s
_________
Up for More?
Demo: Use solubility Reference Table F to predict if a ppt. will form or not?
Compounds Mixed
CoCl2
NaOH
K(NO3)
NaCl
Ag(NO3)
NaCl
Fe(NO3)3
Na(OH)
Fe(NO3)3
Ag(NO3)
Will a ppt. form?
(Y or N)
If yes, which ions
will form the ppt?
Prediction correct
(C) or incorrect (I)
New Challenge…
1. Each of you has an ion card. (Blue : Cations. Yellow:
Anions)
2. Pair up with a person with a card to form an ionic
compound. (one blue/one yellow)
3. Determine if new compound is soluble or insoluble.
4. Write your new compound on the appropriate board
(remember to write chemical formula correctly)
5. Return to your seat and await further instructions.
You have 2.5 minutes
GO!
Challenge Part 2
1. Choose one compound from the insoluble column and one
from the soluble column.
2. Write these compound on your white board.
Be sure to write in the phase for each compound.
Answer:
What were the reactants for your reaction?
What are the spectator ions in the reaction?
Will They Won’t They



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You will work alone on this sheet
You are to do only the questions circled on your WS.
Turn over when complete.
If time begin HW.

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