Activity Series A method for predicting reactions.

Principles of the Activity Series The activity series is a list of elements organized according to their ability to react with certain compounds via a single replacement reaction It can be used to predict products of chemical reactions The most reactive elements are found at the top of the list and can replace any element lower on the activity series

Metals: React with H 2 O The following metals react with cold water and acids, replacing hydrogen Li Rb K Ba Sr Ca Na

Metals: React with Steam The following metals react with steam and acids, replacing hydrogen Mg Al Mn Zn Cr Fe Cd

Metals: React with Acid The following acids react with acids, replacing hydrogen Co Ni Sn Pb

Metals: React with Oxygen The following metals react with oxygen, forming oxides Sb Bi Cu

Metals: Fairly Unreactive The following metals do not react with water, steam, acids, or oxygen (directly) Hg Ag Pt Au

Generalizations An element exposed to an aqueous compound will replace any element below it in the activity series Larger intervals between elements in the activity series make a reaction more plausible The more active a metal the stronger it bonds to oxygen, making decomposition more difficult Elements at the top of the series are never found in nature as uncombined elements Elements at the bottom of the series are often found in nature as uncombined elements

ACTIVITY SERIES PROBLEMS Cr (s) + H 2 O (l)  NO! Water must be steam! Pb (s) + HNO 3(aq)  YES! Pb(NO 3 ) 2 + H 2(g) BaO + Δ  NO! Barium has strong bonds with oxygen. Mg (s) + H 2 O (g)  YES! Mg(OH) 2(aq) + H 2(g)