Precipitation and Redox Rxn. Packet
Name: _________________________________ PD.______
Precipitation Reactions
I.
Determine the oxidation number (charges) of the following:
1.
2.
3.
4.
5.
6.
7.
II.
Li
Sr
Al
I
Ar
(PO4) NH4
(NO3)
Write the compound formed using the provided ions
1. Li + O
2. K + Br
III.
3. Na + (NO3)
4. Mg + (SO4)
5. Mg + (PO4)
What do the following symbols represent?
1.
2.
3.
4.
5.
IV.
aq =
s=
g=
l=
What is a precipitate?
Using a solubility chart, determine if the following compounds will dissolve in water (to
form aqueous solutions) or will stay solid (s). Use the symbols aq or s.
1. Mg(CO3)
2. Be(NO3)2
3. Ba(SO4)
V.
4. PtBr2
5. Ca3(PO4)2
6. K(OH)
Write the double replacement reaction for the following.
1. KI (aq) and Ag(NO3) (aq) are mixed
2. Aqueous solutions of Li2(SO4) and Ca(NO3)2
3. NH4(PO4) (aq) + Na(SO4) (aq)
4. AlCl(aq) + NaOH (aq)
5. What pattern do you notice about the all the reactants?
1
7. AgCl
Precipitation Reactions Activity
Directions for the following 4 reactions:
a. In one well of a well-plate, add three drops of each substance.
b. Write down your observations for the reactants above.
c. In parenthesis provided above, indicate if the product is soluble with an “aq”
or forms a precipitate (solid) with an “s.”
1. Write the double replacement reaction for the reactants NaOH + Pb(NO3)2.
___________ (aq) + ____________ (aq)  ____________ (
) + ____________ (
)
Observations:
___________________________________________________________________
2. Write the double replacement reaction for the reactants CuCl + NaOH.
__________ (aq) + ____________ (aq)  ___________ (
) + ____________ (
)
Observations:
___________________________________________________________________
3. Write the double replacement reaction for the reactants KI + CuCl.
___________ (aq) + ___________ (aq)  ____________ (
) + _____________ (
)
Observations:
___________________________________________________________________
4. Write the double replacement reaction for the reactants NaCO3 + CuCl.
__________ (aq) + __________(aq)
 __________ (
) + ___________(
)
Observations:
__________________________________________________________________
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Mission Possible: Predicting Precipitation Reactions
Your mission: To predict whether a precipitation reaction will take place between two
aqueous solutions of ionic compounds, and if the answer is yes, to write the complete
equation for the reaction.
Ex.
Li2CO3(aq) + Al(NO3)3(aq)  ?
Background: As shown on your Reference Tables, double replacement reactions follow the
general equation:
AB + CD → AD + CB
Mission execution:
STEP 1: Write the formulas for the products AD and CB
Caution: Forgetting to check the charges and criss-cross if necessary will result in
mission failure!
Ex:
Li2CO3(aq) + Al(NO3)3(aq)  LiNO3 + Al2(CO3)3
STEP 2: Use the SOLUBILITY RULES on your Reference Tables to determine whether
either of the possible products is water insoluble. If either possible product is
insoluble, a precipitation reaction takes place, and continue to Step 3. If neither is
insoluble, write “no reaction”- Mission accomplished.
Ex.
LiNO3
Al2(CO3)3
= soluble (all nitrates soluble)
= insoluble (carbonates insoluble; aluminum not an exception)
STEP 3: Put an (s) for solid next to the insoluble product. This is the precipitate formed in
the reaction. It does not dissolve. Put (aq) next to the compound that is watersoluble.
Ex:
Li2CO3(aq) + Al(NO3)3(aq)  LiNO3(aq) + Al2(CO3)3(s)
STEP 4: Balance the equation. Mission accomplished.
Ex:
3 Li2CO3(aq) + 2 Al(NO3)3(aq)  6 LiNO3(aq) +
Practice:
1. KOH(aq) + Fe(NO3)3(aq) →
2. NaC2H3O2(aq) + CaS(aq) →
3. K2SO4(aq) + Pb(NO3)2(aq) →
4. CaCl2(aq) + Na3PO4(aq) →
3
Al2(CO3)3(s)
5. KNO3(aq) + MgI2(aq) →
6. Solutions of iron (II) sulfate and barium hydroxide are mixed.
7. Solutions of calcium nitrate and sodium chloride are mixed.
8. Solutions of potassium chloride and silver nitrate are mixed.
9. Solutions of ammonium sulfate and barium chloride are mixed.
10. Pb(NO3)2(aq) + LiI(aq) →
4
Redox Reactions
1. Provide oxidation numbers for the following:
a.
b.
c.
d.
e.
O2 ______
AlS3
Al_________ S________
P4
P _________
K
K__________
I2
I __________
2. Mnemonic Device
L
E
O
ex.
2H2O  O2 + 2H2
says
G
E
R
ex.
2H2O  O2 + 2H2
3. Reducing Agent: ______________________________
4. Oxidizing Agent : ______________________________
5.
5
Oxidation Numbers & Redox
1.
Perform a reaction between copper (II) chloride and aluminum. Describe the reaction
below.
2.
Write the chemical equation for copper (II) chloride and aluminum.
3.
This chemical reaction is an example of a ____________________ reaction
because there
is a transfer of ____________________ between the atoms. One
atom ______________ gains electrons another atom _________________
electrons.
4.
How do you know if electrons are lost or gained?
5.
When an element undergoes oxidation:
 electrons are ___________
 The oxidation state __________________
 It is the ______________________ agent
6.
When an element undergoes reduction:
 electrons are ___________
 The oxidation state __________________
 It is the ___________________ agent
7.
Which of the following reactions is (are) oxidation-reduction reactions?
a) Zn(OH)2(s) + H2SO4(aq)  ZnSO4(aq) + 2 H2O(l)
b) Ca(s) + 2 H2O(l)  Ca(OH)2(s) + H2(g)
8.
Which of the following reactions is (are) oxidation-reduction reactions?
a) 2 Ca(s) + O2(g)  2 CaO(s)
b) Ca(OH)2(s) + 2 HCl(aq)  CaCl2(aq) + 2 H2O(l)
6