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concentration in the solution. At a constant temperature and concentration the

equilibrium potential is constant.

Absolute values of electrode potentials cannot be measured. Then the relative

values are measured, that is, the potentials difference between two different

electrodes immersed in the solutions of the corresponding salts is measured. A

standard hydrogen electrode is used as a standard electrode compared with the

potentials of other metals, whose potential is conventionally assumed to be zero.

The electrode potential, measured under standard conditions (temperature 298.15

K, pressure of gaseous substance 1 atm (101325 Pa), ion concentration 1 mol · eq /

3
dm ), is called the standard electrode potential φ о. Determination of standard
electrode potentials made it possible to create a range of standard electrode

potentials.

Interaction of metals with aqueous salts solutions.
Each metal displaces from the aqueous salts solutions other metals located in the

range of standard electrode potentials (see supplement E) to the right of it and can
be self-displaced by the metals to the left. This statement is valid for solutions

with salt concentrations of 1 mol · eq / dm3.
Fe + CuCl 2 → FeCl 2 + Cu,

FeCl 2 + Cu ≠.

Interaction of metals with water.

Alkali and alkaline earth metals and thallium interact with water at a normal

temperature. In this case the corresponding alkalis are formed and Hydrogen is

released. For example:

Са + 2H 2О = Са(ОН) 2 + Н 2↑,

2Тl + 2H 2О = 2ТlОН + Н 2↑.

Beryllium and magnesium interact with hot water.

During the reactions of Metals of medium activity the oxides are formed.

For example:

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