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) + 2AgNO 3 (aq)  2Ag(s) + Cu(NO 3 ) 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(NO 3 ) 2 (aq)  NR (no reaction)

Examples Predict whether the following replacement reactions will occur. If a reaction occurs, write a balanced equation for the reaction. A.Fe(s) + CuSO 4 (aq)  B.Br 2 (l) + MgCl 2 (aq)  C.Mg(s) + AlCl 3 (aq)  D.LiI(aq) + AgNO 3 (aq) 

Practice Problems Predict whether the following replacement reactions will occur. If a reaction occurs, write a balanced equation for the reaction. A.K(s) + ZnCl 2 (aq)  B.Cl 2 (g) + HF(aq)  C.Fe(s) + Na 3 PO 4 (aq)  D.Al(s) + Pb(NO 3 ) 2 (aq) 