Replacement Reactions & the Activity Series

Learning Objective

• Use an activity series to predict whether a reaction will occur.

• Predict the products of a chemical reaction.

Replacement Reactions

Replacement reactions involve the replacement of an element in a compound.• Ex: Cu(s) + 2AgNO3(aq)

2Ag(s) + Cu(NO3)2(aq)• In this reaction copper

replaces silver when a bar of pure copper is placed in aqueous silver nitrate.

Replacement Reactions

• A metal will not always replace another metal in a compound dissolved in water because metals differ in their reactivities.

Replacement Reactions

• An activity series of metals is a listing of the metals in order of their ability to displace one another from solutions.

• An activity series is useful for – determining whether a

reaction will occur– predicting products of a

replacement reaction

Replacement Reactions

• A specific metal can replace any metal listed below it that is in a compound.

• It cannot replace any metal listed above it.

Ex: If you place a silver wire in aqueous copper(II) nitrate, the silver atom will not replace the copper. Ag(s) + Cu(NO3)2(aq) NR (no reaction)

ExamplesPredict whether the following replacement reactions will occur. If a reaction occurs, write a balanced equation for the reaction. A. Fe(s) + CuSO4(aq)

B. Br2(l) + MgCl2(aq)

C. Mg(s) + AlCl3(aq)

D. LiI(aq) + AgNO3(aq)

Practice ProblemsPredict whether the following replacement reactions will occur. If a reaction occurs, write a balanced equation for the reaction. A. K(s) + ZnCl2(aq)

B. Cl2(g) + HF(aq)

C. Fe(s) + Na3PO4(aq)

D. Al(s) + Pb(NO3)2(aq)