Predicting the Product in Single Replacement

ReactionsUsing the Activity Series

Introduction• In a single replacement reaction, the metal ion

in a salt solution is replaced by another metal.

AX(aq) + B(s) → BX(aq) + A(s)

• For example:

• Adding magnesium metal to a solution of silver chloride causes the magnesium to dissolve and the silver to precipitate out.

2 AgNO3(aq) + Mg(s) → Mg(NO3)2(aq) + 2 Ag(s)

Introduction• In a single replacement reaction, the halide in

a salt solution is replaced by another halide.

AX(aq) + Y2 → AY(aq) + X2

• For example:

• Adding chlorine gas to a solution of sodium bromide causes the chlorine to dissolve and the bromine to come out as a liquid.

2 NaBr(aq) + Cl2(g) → 2 NaCl(aq) + Br2(l)

Introduction• These kinds of reactions do not occur with all

combinations of metals or halogens.

• Some metals will replace some other metal ions in solution.

• Some halogens will replace some other halogen ions in solution.

• However, not every metal will replace every other metal ion in solution.

Metals• The metals that replace other metal ions are

said to be “more active” than the metals they replace.

• For example, in the reaction

2 AgNO3(aq) + Mg(s) → Mg(NO3)2(aq) + 2 Ag(s)

•The metal Mg is more active than the Ag+ ion.

• By examining a series of reactions with solid metals and dissolved metal ions, we can build a list of metals based on activity.

• We call this the “Activity Series.”

Metals• The most active metal is Li followed by Rb, K,

Ba, Sr, Ca, and Na.

• Each of these metals react with cold water and acids, replacing H.

2 Li(s) + H2O(l) → Li2O(s) + H2(g)

2 K(s) + HCl(aq) → 2 KCl(aq) + H2(g)

Metals• The most active metal is Li followed by Rb, K,

Ba, Sr, Ca, and Na.

• Each of these metals react with O2(g), forming oxides.

2 Ba(s) + O2(g) → 2 BaO(s)

2 Rb(s) + O2(g) → Rb2O(s)

Metals• The next most active set of metals is Mg

followed by Al, Mn, Zn, Cr, Fe, and Cd.

• Each of these metals react with H2O(g) and acids, replacing hydrogen.

Mg(s) + H2O(g) → MgO(s) + H2(g)

Zn(s) + 2 HNO3(aq) → Zn(NO3)2(aq) + H2(g)

Metals• The next most active set of metals is Mg

followed by Al, Mn, Zn, Cr, Fe, and Cd.

• Each of these metals react with O2(g), forming oxides.

2 Zn(s) + O2(g) → 2 ZnO(s)

4 Fe(s) + 3 O2(g) → 2 Fe2O3(s)

Metals• The next most active set of metals is Co

followed by Ni, Sn, and Pb.

• None of these metals react with H2O (hot or cold).

• They do react with acids, replacing hydrogen.

Co(s) + 2 HNO3(aq) → Co(NO3)2(aq) + H2(g)

Pb(s) + H2SO4(aq) → PbSO4(aq) + H2(g)

Metals• The next most active set of metals is Co

followed by Ni, Sn, and Pb.

• Each of these metals react with O2(g), forming oxides.

2 Ni(s) + O2(g) → 2 NiO(s)

2 Sn(s) + O2(g) → 2 SnO(s)

Metals• The next most active set of metals is Sb

followed by Bi, Cu, and Hg.

• None of these metals react with water or acids.

• Each of these metals react with O2(g), forming oxides.

4 Sb(s) + 3 O2(g) → 2 Sb2O3(s)

2 Cu(s) + O2(g) → 2 CuO(s)

Metals• The least active set of metals is Ag followed by

Pt and Au.

• These metals are fairly unreactive.

• None of these metals react with water or acids.

• None of these metals react directly with O2(g) to form oxides.

• They will form oxides, but only indirectly.

Metals• The Activity Series:

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

most active

least active

incr

easi

ng

act

ivit

y

incr

easi

ng

act

ivit

y

incr

easi

ng

act

ivit

y

incr

easi

ng

act

ivit

y

incr

easi

ng

act

ivit

y

Halogens• The most active halogen is F2 followed by Cl2,

Br2, and I2.

• Each of these halogens are reactive with a wide variety of elements and compounds.

• The activity series just shows which is most reactive and least reactive.

Halogens• The Activity Series:

F2

Cl2

Br2

I2

most active

least active

incr

easi

ng

act

ivit

y

Using the Activity Series• The activity series is used to predict whether

or not a single replacement reaction will occur.

• First, we look at the ions in a solution.

• Next, we look at the metal or halogen being added to the solution.

• If the metal is higher up on the activity series list, then it goes into solution and the metal ion in solution precipitates out.

• If the metal is lower down on the activity series list, then there is no reaction.

Using the Activity Series• The activity series is used to predict whether

or not a single replacement reaction will occur.

• First, we look at the ions in a solution.

• Next, we look at the metal or halogen being added to the solution.

• If the halogen is higher up on the activity series list, then it goes into solution and the halide ion in solution comes out as a solid, liquid, or gas.

• If the halogen is lower down on the activity series list, then there is no reaction.

Using the Activity Series• For example:

• We put zinc metal in a solution of copper(II) sulfate.

Using the Activity Series• For example:

• We put zinc metal in a solution of copper(II) sulfate.

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

Using the Activity Series• For example:

• We put zinc metal in a solution of copper(II) sulfate.

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

Using the Activity Series• For example:

• We put zinc metal in a solution of copper(II) sulfate.

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

Zn is more active than Cu.

Using the Activity Series• For example:

• We put zinc metal in a solution of copper(II) sulfate.

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

Zn is more active than Cu.

Zn(s) will replace Cu2+(aq).

Using the Activity Series• For example:

• We put zinc metal in a solution of copper(II) sulfate.

• We predict that the solid zinc will dissolve in the solution (forming Zn2+ ions) and copper metal will precipitate out.

Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)

Using the Activity Series• For example:

• We put magnesium metal in a solution of iron(III) chloride.

Using the Activity Series• For example:

• We put magnesium metal in a solution of iron(III) chloride.

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

Using the Activity Series• For example:

• We put magnesium metal in a solution of iron(III) chloride.

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

Using the Activity Series• For example:

• We put magnesium metal in a solution of iron(III) chloride.

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

Mg is more active than Fe.

Using the Activity Series• For example:

• We put magnesium metal in a solution of iron(III) chloride.

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

Mg is more active than Fe.

Mg(s) will replace Fe3+(aq).

Using the Activity Series• For example:

• We put magnesium metal in a solution of iron(III) chloride.

• We predict that the solid magnesium will dissolve in the solution (forming Mg2+ ions) and iron metal will precipitate out.

3 Mg(s) + 2 FeCl3(aq) → 3 MgCl2(aq) + 2 Fe(s)

Using the Activity Series• For example:

• We put copper metal in a solution of iron(III) chloride.

Using the Activity Series• For example:

• We put copper metal in a solution of iron(III) chloride.

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

Using the Activity Series• For example:

• We put copper metal in a solution of iron(III) chloride.

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

Using the Activity Series• For example:

• We put copper metal in a solution of iron(III) chloride.

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

Fe is more active than Cu.

Using the Activity Series• For example:

• We put copper metal in a solution of iron(III) chloride.

Li Mg Co Sb Ag

Rb Al Ni Bi Pt

K Mn Sn Cu Au

Ba Zn Pb Hg

Sr Cr

Ca Fe

Na Cd

Fe is more active than Cu.

Cu(s) will not replace Fe3+(aq).

Using the Activity Series• For example:

• We put copper metal in a solution of iron(III) chloride.

• We predict that there will be no reaction.

Cu(s) + FeCl3(aq) → no reaction

Using the Activity Series• For example:

• We add chlorine gas to a solution of iron(III) iodide.

Using the Activity Series• For example:

• We add chlorine gas to a solution of iron(III) iodide.

F2

Cl2

Br2

I2

Using the Activity Series• For example:

• We add chlorine gas to a solution of iron(III) iodide.

F2

Cl2

Br2

I2

Using the Activity Series• For example:

• We add chlorine gas to a solution of iron(III) iodide.

Cl2 is more active than I2.

F2

Cl2

Br2

I2

Using the Activity Series• For example:

• We add chlorine gas to a solution of iron(III) iodide.

Cl2 will replace I−.

F2

Cl2

Br2

I2

Cl2 is more active than I2.

Using the Activity Series• For example:

• We add chlorine gas to a solution of iron(III) iodide.

• We predict that the chlorine gas will go into solution (forming a Cl− ion) and the iodine will come out as a solid.

3 Cl2(g) + 2 FeI3(aq) → 2 FeCl3(aq) + 3 I2(s)

Using the Activity Series• For example:

• We add chlorine gas to a solution of iron(III) fluoride.

Using the Activity Series• For example:

• We add chlorine gas to a solution of iron(III) fluoride.

F2

Cl2

Br2

I2

Using the Activity Series• For example:

• We add chlorine gas to a solution of iron(III) fluoride.

F2

Cl2

Br2

I2

Using the Activity Series• For example:

• We add chlorine gas to a solution of iron(III) fluoride.

F2 is more active than Cl2.

F2

Cl2

Br2

I2

Using the Activity Series• For example:

• We add chlorine gas to a solution of iron(III) fluoride.

Cl2 will not replace F−.

F2

Cl2

Br2

I2

F2 is more active than Cl2.

Using the Activity Series• For example:

• We add chlorine gas to a solution of iron(III) fluoride.

• We predict that there will be no reaction.

Cl2(g) + FeF3(aq) → no reaction

Practice ProblemsUse the activity series to predict the products of the following reactions. Indicate if there is no reaction.

1. Mg(s) + Cu(NO3)2(aq) →

2. Fe(s) + AgNO3(aq) →

3. Cu(s) + AgNO3(aq) →

4. Fe(s) + Na2SO4(aq) →

5. Pb(s) + Co(NO3)2(aq) →

6. Al(s) + SnSO4(aq) →

7. Zn(s) + MnCl2(aq) →

Mg(NO3)2(aq) + Cu(s) 3 Fe(NO3)3(aq) + 3 Ag(s) 2 Cu(NO3)2(aq) + 2 Ag(s) no reaction

no reaction

2 3 Al2(SO4)3(aq) + 3 Sn(s) no reaction

Summary• The activity series is used to predict whether

or not a single replacement reaction will occur.

• First, we look at the ions in a solution.

• Next, we look at the metal or halogen being added to the solution.

• If the metal is higher up on the activity series list, then it goes into solution and the metal ion in solution precipitates out.

• If the metal is lower down on the activity series list, then there is no reaction.

• The activity series is used to predict whether or not a single replacement reaction will occur.

• First, we look at the ions in a solution.

• Next, we look at the metal or halogen being added to the solution.

• If the halogen is higher up on the activity series list, then it goes into solution and the halide ion in solution comes out as a solid, liquid, or gas.

• If the halogen is lower down on the activity series list, then there is no reaction.

Summary