Question

Define the reactivity series of metals.

Answer 1

Hint: Reactivity series of metal also known as electrochemical series.
The electrochemical series is a list of standard electrode potential values of various metal electrode half cells arranged in increasing order of standard reduction potential from top to bottom.
The tendency to lose electrons or to get oxidised is known as oxidation potential, while the tendency to gain electrons or to get reduced is known as reduction potential.
It is not possible to determine the absolute value of electrode potential because there is no way to isolate a single half-cell. The electrode potential can be determined by coupling it with a standard hydrogen electrode by forming a cell.

Complete step by step answer:
-The electrode potential is simply the difference of potential between two electrodes that we can measure by combining two half-cells.
-In electrochemical series highly active metals are placed top of the chart, which have negative reduction potential and are strongly electropositive. On moving down the series the value of electrode potential increases and activity of metal decreases. In this series alkali and alkaline earth metal are placed in the top while fluorine is present in the base of the series which have the highest value of standard reduction potential. In this series hydrogen is present in the middle of the series whose value of standard reduction potential is zero.
-According to electrochemical series the electrode with higher reduction potential will act as a cathode and electrode with more negative reduction potential will act as anode.
-An active metal can displace the metal ion listed below in the electrochemical series from its salt solution, but not above metal. For example $\text{Zn}$ is more active metal then $\text{Cu}$ so $\text{Zn}$ metal is able to displace $\text{Cu}$ ion from it salt solution, while $\text{Ag}$ metal cannot displace $\text{Cu}$ ion from its salt solution because it lies below the $\text{Cu}$ in electrochemical series.

Note: At anode oxidation takes place while at cathode reduction takes place.
-Those metals which can easily displace ${{\text{H}}^{\text{+}}}$ ion from acids are easily recognised by their position above the hydrogen in the electrochemical series. Sodium is highly active metal which is capable to displace ${{\text{H}}_{\text{2}}}$ gas from ${{\text{H}}_{\text{2}}}\text{O}$.