Activity series

Activity series is a list that ranks different metals and hydrogen in order of their reactivity. It is also known as the reactivity series or electrochemical series. The activity series is a useful tool in predicting the outcomes of chemical reactions, particularly displacement reactions.

Overview

The activity series is based on the observation that some metals are more reactive than others. In a displacement reaction, a more reactive metal will displace a less reactive metal from its compound. For example, if a piece of zinc metal is placed in a copper sulfate solution, the zinc will displace the copper from the sulfate, forming zinc sulfate and copper metal.

The activity series is arranged with the most reactive metals at the top and the least reactive at the bottom. The series begins with potassium, the most reactive metal, and ends with gold, the least reactive. Hydrogen is also included in the series, allowing for predictions about reactions involving acids.

Use in Predicting Reactions

The activity series can be used to predict the outcomes of a variety of chemical reactions. For example, it can predict whether a metal will react with an acid to produce hydrogen gas. Metals above hydrogen in the series will react with acids, while those below will not.

The series can also predict the outcomes of displacement reactions between metals and metal ions in solution. A metal will displace any metal ion below it in the series from a solution of its salts.

Limitations

While the activity series is a useful tool in predicting the outcomes of chemical reactions, it has its limitations. It does not take into account the concentrations of the reactants or the conditions under which the reaction takes place. Therefore, it should be used as a general guide rather than a definitive predictor of chemical reactions.

See Also

• Chemical reactivity
• Redox reactions
• Electrochemistry

References

• Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN 0-618-94690-X.
• Petrucci, Ralph H.; Harwood, William S.; Herring, F. Geoffrey (2002). General Chemistry (8th ed.). Prentice Hall. ISBN 0-13-014329-4.