Predicting the Product in Single Replacement Reactions

1. Predicting the Product in Single Replacement Reactions • Using the Activity Series

2. Introduction There are two types of single replacement reactions, A) The metal ion in a solution is replaced by another metal. 2 AgNO3(aq) + Mg(s) → Mg(NO3)2(aq) + 2 Ag(s) B) The halide in a solution is replaced by another halide. 2 NaBr(aq) + Cl2(g) → 2 NaCl(aq) + Br2(l)

3. 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.”

4. Metals Halides F2 Cl2 Br2 I2 • The Activity Series: most active most active increasing activity increasing activity increasing activity increasing activity increasing activity increasing activity least active least active

5. 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 replacementto occur. • If the added metal is lower down on the activity series list, then it is less reactive, and there is no reaction.

6. Using the Activity Series • For example: • We put zinc metal in a solution of copper(II) sulfate. Zn is more active than Cu. Zn(s) will replace Cu2+(aq). Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)

7. Using the Activity Series • For example: • We put magnesium metal in a solution of iron(III) chloride. Mg is more active than Fe. Mg(s) will replace Fe3+(aq). 3 Mg(s) + 2 FeCl3(aq) → 3 MgCl2(aq) + 2 Fe(s)

8. Using the Activity Series • For example: • We put copper metal in a solution of iron(III) chloride. Fe is more active than Cu. Cu(s) will notreplace Fe3+(aq). Cu(s) + FeCl3(aq) → no reaction

9. Using the Activity Series • For example: • We add chlorine gas to a solution of iron(III) iodide. Cl2 is more active than I2. Cl2 will replace I−. 3 Cl2(g) + 2 FeI3(aq) → 2 FeCl3(aq) + 3 I2(s)

10. Practice Problems Use the activity series to predict the products of the following reactions. Indicate if there is no reaction. • Mg(s) + Cu(NO3)2(aq) → • Fe(s) + AgNO3(aq) → • Fe(s) + Na2SO4(aq) → • Pb(s) + Co(NO3)2(aq) → Mg(NO3)2(aq) + Cu(s) 3 Fe(NO3)3(aq) + 3 Ag(s) no reaction no reaction