What Is The Electrochemical Series

Different combinations of metals produce different voltages and this depends on how strongly the metal could force its electrons to move across a cell. The electrochemical series is a list of metals and other substances arranged in rank order of how easily their atoms may lose electrons. The further apart the metals are in the electrochemical series, the higher the voltage produced across the cell. Electrons flow along the wire from the metal higher in the electrochemical series to the metal lower down. The electrode potentials are arranged in the substances ability to donate its electrons; that is, how easily they are oxidised. All of the values are measured in Volts. Hydrogen has an electrode potential of 0V. The significance is that this is a reference. All of the other electrode potentials are measured against this value. The electrons always move from the metal with the more negative electrode potential to the more positive electrode potential. You can also use the electrochemical series to predict a displacement reaction when a metal from the electrochemical series is mixed with the ions of a metal lower down in the series. The atoms of the more reactive metal push their electrons on to ions of the less reactive metal. The higher up the metal in the electrochemical series is the one that always displaces the ions of the lower down metal. Metals lower down in the the series cannot displace more reactive metals from their solutions. You can use this idea to predict whether a displacement reaction will occur.