Practice Homework 19: Predicting Products – Double Replacement (DR)
Basic Information

This assignment is for practice only. It is not due.

You will need the following reference tables for this practice assignment:

Periodic Table

Solubility Rules

Remember that it helps to name the product before writing its chemical formula.

The “training wheels are off”: If a substance does not need parentheses, I will no longer write them.
Those of you going into CHEM 120 should get into the habit of doing the same.

Do not balance these equations. I just want to see if you can predict the products.

If you balance these equations – and the balance is incorrect – you will lose points.

If there is no reaction (all reactants and products are aqueous), write NR in the first blank.
Definitions/Helpful Info

A double replacement (DR) reaction is when the cations and anions of the two reactants “switch partners.

A possible DR rxn is indicated when the two reactants are ionic compounds.

A neutralization reaction (NEUT) is a special kind of DR rxn that occurs when an acid ( HA(aq) ) and a base
(metal hydroxide) react to form an ionic compound and water.

When you are asked to balance NEUT rxns, writing H2O as HOH will be helpful.

If there is no reaction (all reactants and products are aqueous), write NR in the first blank.
1)
NaCl(aq)
+
Pb(NO3)2(aq)

2)
AgNO3(aq)
+
MgI2(aq)

3)
HCl(aq)
+
Cu(OH)2(s)

4)
Li2CO3(aq)
+
BaCl2(aq)

5)
K3PO4(aq)
+
(NH4)2SO4(aq)

6)
NaF(aq)
+
Cr(NO3)6(aq)

7)
Ca(OH)2(s)
+
H3PO4(aq)

8)
KI(aq)
+
MgBr2(aq)

9)
Na2CrO4(aq)
+
FeCl3(aq)

10)
KMnO4(aq)
+
Cu(ClO4)2(aq)

Page 1 of 2
ANSWERS
1)
NaCl(aq)
+
Pb(NO3)2(aq)

NaNO3(aq) + PbCl2(s)
2)
AgNO3(aq)
+
MgI2(aq)

AgI(s) + Mg(NO3)2(aq)
3)
HCl(aq)
+
Cu(OH)2(s)

CuCl2(aq) + HOH(l)
OR
CuCl2(aq) + H2O(l)
NR
NR
LiCl(aq) + BaCO3(s)
4)
Li2CO3(aq)
+
BaCl2(aq)

5)
K3PO4(aq)
+
(NH4)2SO4(aq)

6)
NaF(aq)
+
Cr(NO3)6(aq)

CrF6(s) + NaNO3(aq)
Ca3(PO4)2(s) + HOH(l)
or
Ca3(PO4)2(s) + H2O(l)
7)
Ca(OH)2(s)
+
H3PO4(aq)

8)
KI(aq)
+
MgBr2(aq)

9)
Na2CrO4(aq)
+
FeCl3(aq)

NaCl(aq) + Fe2(CrO4)3(s)
10)
KMnO4(aq)
+
Cu(ClO4)2(aq)

KClO4(aq) + Cu(MnO4)2(s)
Page 2 of 2