Predicting Single Displacement Reactions The Reactivity Series Predicting Single Displacement Reactions

THE REACTIVITY SERIES Not every single-replacement reaction will happen. The element on the reactant side must be more “active” than the one it could replace. Scientists have listed the order of activity of elements in THE ACTIVITY SERIES.

Fe + Cu Sulphate  Cu + Fe Sulphate Li + H2O  Li Hydroxide + H2 Let’s look at several reactions: Don’t worry about how to write the formula yet Fe + Cu Sulphate  Cu + Fe Sulphate Li + H2O  Li Hydroxide + H2 Such experiments reveal trends. The activity series ranks the relative reactivity of metals. It allows us to predict if certain chemicals will undergo single displacement reactions when mixed: metals near the top are most reactive and will displace metals near the bottom. Q: Which of these will react? Fe + Cu Sulphate  Ni + Na Chloride  Li + Zn Carbonate  Al + Cu Chloride  K Na Li Ca Mg Al Zn Fe Ni Sn Pb H Cu Hg Ag Au No, Ni is below Na Yes, Li is above Zn Yes, Al is above Cu Yes, Fe is above Cu

Complete the following equations using chemical names. Ex. Fe+ Cu Sulphate Fe Sulphate + Cu Ni + Na Chloride  Li + Zn Carbonate  Al + Cu Chloride 

Displacement reactions: metals Copper is quite low in the activity series. Several metals will displace it from its compounds. copper sulphate solution magnesium magnesium sulphate solution copper metal K Na Ca Mg Al Zn Fe Cu Ag Au + Copper sulphate Magnesium  Magnesium sulphate + Copper more reactive less reactive Magnesium wins the competition. Copper is displaced.

Displacement reactions: metals Here are some actual photos. The colour changes from blue to red/black as copper metal is displaced. photograph at start of reaction photograph at end of reaction K Na Ca Mg Al Zn Fe Cu Ag Au + Copper sulphate  Magnesium sulphate Magnesium + Copper more reactive less reactive Magnesium wins the competition. Copper is displaced

A: No for cold, yes if it is hot/steam Mg + H2O  H2 + Mg Hydroxide H is the only nonmetal listed. H2 may be displaced from acids or can be given off when a metal reacts with H2O (producing H2 + metal hydroxide). The reaction with H2O depends on metal reactivity & water temp. Q: will Mg react with H2O? K Na Li Ca Mg Al Zn Fe Ni Sn Pb H Cu Hg Ag Au cold H2O hot H2O steam A: No for cold, yes if it is hot/steam Mg + H2O  H2 + Mg Hydroxide acid Q: Zn + HCl  H2 + Zn Chloride General Rule if there is a reaction: Metal + Water = Hydrogen gas + Metal hydroxide Metal + Hydrogen Chloride (Hydrochloric acid) = Hydrogen gas + Metal Chloride

Complete these reactions: Al + H2O(steam)  Cu + H2O  Ca + H2SO4  Na + H2O 

Complete these reactions: Al + H2O(steam)  Cu + H2O  NR Ca + H2SO4  Na + H2O 

Other Activity Series Information All metals will have a specific place in the activity series. For simplicity, only the most common metals are shown. The metals near the top of the activity series are more reactive because their valence electrons are more easily removed. On tests and exams the activity series may appear as K, Na, … Ag, Au; you must remember that K is reactive, Au is not. If the valence of a metal is not indicated in the question, use its most common valence (in bold on your periodic table) to determine the correct chemical formula.