Tag: reactivity series and electrochemistry

The reactivity series is a series of metals, arranged in order of reactivity from highest to lowest. It is used to determine the products of single displacement reactions, whereby metal A will replace another metal B in a solution if A is higher in the series.

$2Na + ZnCl _2 \rightarrow 2NaCl + Zn$

Among given metal oxides, magnesium have very low reduction potential so it can not be reduced by normal reducing agents.

Gold is least reactive metal because of higher standard reduction potential value.

Magnesium can displace hydrogen from steam. Mg is better reducing agent than hydrogen as Mg les above hydrogen in the reactivity series.
Hence, the tendency for the reaction $\displaystyle Mg \rightarrow Mg^{2+} + 2e^-$ is greater than the tendency for the reaction $\displaystyle 2H^+ + 2e^- \rightarrow H _2$. Hence, Mg will be oxidised and $\displaystyle H^+$ will be reduced.

The activity series is a listing of the metals in decreasing order of their reactivity with hydrogen ion sources such as water and acids. In the reaction with hydrogen ion source the metal is oxidized to a metal ion and the hydrogen is reduced to hydrogen gas. They are also good reducing agents and poor oxidizing agents.

Silver is the metal which is present at the bottom of reactivity series below $Mg$ and $Cu$ metals so it cannot displace these metals from its solution. In this case, no reaction takes place by this piece of silver.

In order to prevent the spoilage of potato chips, they are packed in plastic bags in an atmosphere of $N _2$ to prevent from being rancid or oxidised. 
Nitrogen is added to the potato chip packet to add strength to the packaging. Normally aluminium cans are used for packaging beverages, these beverages are carbonated drinks and the carbon dioxide present in them provides the internal pressure in the can and thus gives internal strength to the aluminium can. But in non-carbonated drinks, there is no carbon dioxide present and so Nitrogen is added to it to give the required strength to the packing.

Since, the copper is present below the hydrogen in the activity series it cannot displace hydrogen from the sulphuric acid.

$Li$ and $Na$ both metals belong to the alkali metals.