The Activity Series Predicting Single Displacement Reactions
THE ACTIVITY 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.
No, Ni is below Na Yes, Li is above Zn Yes, Al is above Cu Yes, Fe is above Cu Let’s look at several reactions: Fe + CuSO4 Cu + Fe2(SO4)3 Li + H2O LiOH + 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 + CuSO4 Ni + NaCl Li + ZnCO3 Al + CuCl2 Cu + Fe2(SO4)3 NR (no reaction) Zn + Li2CO3 Cu + AlCl3
cold H2O hot H2O 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? steam A: No for cold, yes if it is hot/steam Mg + H2O H2 + Mg(OH)2 acid Q: Zn + HCl H2 + ZnCl2 Complete these reactions: Al + H2O(steam) Cu + H2O Ca + H2SO4 Na + H2O H2 + Al(OH)3 NR H2 + CaSO4 H2 + NaOH
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.
Yes, F2 is above Br2 No, I2 is below Cl2 There is also an activity series for non-metals: The activity series ranks the relative reactivity of non-metals. It allows us to predict if certain chemicals will undergo single displacement reactions when mixed: non-metals near the top are most reactive and will displace non-metals near the bottom. Q: Which of these will react? I2 + 2NaCl F2 + 2NaBr NR (no reaction) Br2 + 2NaCl