Predicting the Product in Single Replacement Reactions Using the Activity Series

Introduction There are two types of single replacement reactions, A) The metal ion in a solution is replaced by another metal. 2 AgNO 3 (aq) + Mg(s) → Mg(NO 3 ) 2 (aq) + 2 Ag(s) B) The halide in a solution is replaced by another halide. 2 NaBr(aq) + Cl 2 (g) → 2 NaCl(aq) + Br 2 (l)

Introduction These reactions do not happen all the time! Some metals will replace other metal ions in solution. However, not every metal will replace every other metal ion in a solution. The same is true for the halides. The list of activity or reactivity for these elements is called the “Activity Series.”

Metals Halides The Activity Series: LiMgCoSbAg RbAlNiBiPt KMnSnCuAu BaZnPbHg SrCr CaFe NaCd most active least active increasing activity F 2 Cl 2 Br 2 I 2 most active least active increasing activity

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, and determine what is being replaced. If the added metal is higher up on the activity series list, then it is more reactive and causes a replacement to occur. If the added metal is lower down on the activity series list, then it is less reactive, and there is no reaction.

Using the Activity Series For example: We put zinc metal in a solution of copper(II) sulfate. LiMgCoSbAg RbAlNiBiPt KMnSnCuAu BaZnPbHg SrCr CaFe NaCd Zn is more active than Cu. Zn(s) will replace Cu 2+ (aq). Zn(s) + CuSO 4 (aq) → ZnSO 4 (aq) + Cu(s)

Using the Activity Series For example: We put magnesium metal in a solution of iron(III) chloride. LiMgCoSbAg RbAlNiBiPt KMnSnCuAu BaZnPbHg SrCr CaFe NaCd Mg is more active than Fe. Mg(s) will replace Fe 3+ (aq). 3 Mg(s) + 2 FeCl 3 (aq) → 3 MgCl 2 (aq) + 2 Fe(s)

Using the Activity Series For example: We put copper metal in a solution of iron(III) chloride. LiMgCoSbAg RbAlNiBiPt KMnSnCuAu BaZnPbHg SrCr CaFe NaCd Fe is more active than Cu. Cu(s) will not replace Fe 3+ (aq). Cu(s) + FeCl 3 (aq) → no reaction

Using the Activity Series For example: We add chlorine gas to a solution of iron(III) iodide. Cl 2 will replace I −. F2F2 Cl 2 Br 2 I2I2 Cl 2 is more active than I 2. 3 Cl 2 (g) + 2 FeI 3 (aq) → 2 FeCl 3 (aq) + 3 I 2 (s)

Practice Problems Use the activity series to predict the products of the following reactions. Indicate if there is no reaction. 1. Mg(s) + Cu(NO 3 ) 2 (aq) → 2. Fe(s) + AgNO 3 (aq) → 3. Fe(s) + Na 2 SO 4 (aq) → 4. Pb(s) + Co(NO 3 ) 2 (aq) → Mg(NO 3 ) 2 (aq) + Cu(s) 3 Fe(NO 3 ) 3 (aq) + 3 Ag(s) no reaction