Lab: Metal Activity Series – Single Replacement Reactions Purpose To determine the more reactive metal from each pair tested using single replacement reactions To determine the activity series for the set of metals investigated Theory In single replacement reactions an elemental form is combined with an ionic compound in solution (aqueous). By being dissolved in water, the ions are free to bind to other ions and react with the elemental reactant. The most active elements are the most reactive and form compounds rather than remain in elemental forms. For non-metals, atoms that attract and hold onto valence (bonding) electrons the strongest form ionic compounds with available cations. Of the halogens, fluorine has valence electrons in the lowest energy level so they are attracted the strongest to the positively charged nucleus. The other halogens, chlorine, bromine, and iodine, have increasingly higher valence energy levels and reduced attraction to the nucleus. Each metal can be compared to another metal using a pair of single replacement reactions. Each metal will be placed in a solution of the other metal. Only one “metal–metal solution” pair should result in a reaction. The most reactive metal will be the elemental metal that reacts with the solution. Variables Chemicals Materials Dependent Observed evidence of reaction Independent metal pairs (Cu-Mg, Cu-Zn, Mg-Zn) Constants soluble metal salts used sufficient ions for visible reaction same solutions were used throughout no contamination test tubes were cleaned thoroughly before using no contamination copper, Cu, ribbon copper (II) sulfate, CuSO4 (aq), solution magnesium, Mg, turnings magnesium nitrate, Mg(NO3)2 (aq), solution zinc, Zn, mossy zinc nitrate, , Zn(NO3)2 (aq), solution test tubes (6 large) spatula test tube brush Procedure Preparation The six (6) large test tubes were cleaned thoroughly to remove any residue Two small samples of each metal were obtained and observed. The three solutions were obtained and observed. Reactions Copper – Magnesium 2 mL of copper (II) sulfate was placed in test tube A and a sample of magnesium was added. 2 mL of magnesium nitrate was placed in test tube B and a sample of copper was added. This was repeated for copper and zinc and for magnesium and zinc. All observations of the reaction mixtures were recorded. All observations for evidence of reaction were made and recorded. Any evidence that a reaction did not happen were also recorded. Results: Raw Data Table 1. Description of reactants (before reactions). Chemical Description copper metal magnesium metal zinc metal copper solution magnesium solution zinc solution Table 2. Observations of reaction mixtures. This is what was observed not conclusions about whether a reaction happened or not. Copper – Magnesium A copper solution + Mg B magnesium solution + Cu Copper – Zinc C copper solution + Zn D zinc solution + Cu Magnesium - Zinc E magnesium solution + Zn F magnesium solution + Mg