Explain the concept of the reactivity series of... - SS2 Chemistry Metals and Metallurgy Question

The reactivity series is a list of metals arranged in order of their relative reactivity towards displacement reactions. In this series, metals are placed in descending order, starting from the most reactive metal to the least reactive metal. The reactivity series helps predict the outcome of displacement reactions between metals and metal ions in aqueous solutions.

Trends observed in the reactivity series:

●     Most Reactive Metals: Metals such as potassium, sodium, and calcium are at the top of the reactivity series and are highly reactive. They readily react with water or acids to release hydrogen gas and form metal hydroxides or metal salts.

●     Less Reactive Metals: Metals like iron, zinc, and aluminium are less reactive. They react with acids but not with water. They displace hydrogen from acids but not from water.

●     Least Reactive Metals: Metals such as copper, silver, and gold are at the bottom of the reactivity series and are the least reactive. They do not readily react with water or acids and do not displace hydrogen from acids.

The reactivity series is significant in predicting displacement reactions. A metal higher in the reactivity series can displace a metal lower in the series from its salt solution. This displacement reaction occurs because a more reactive metal has a greater tendency to lose electrons and form positive ions, which can replace less reactive metals in their compounds.

For example, according to the reactivity series, zinc (Zn) is more reactive than copper (Cu). Therefore, when zinc is added to a copper sulphate (CuSO4) solution, a displacement reaction occurs:

Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)

In this reaction, zinc displaces copper from the copper sulphate solution, resulting in the formation of zinc sulphate and copper metal.

The reactivity series helps in understanding the relative reactivity of metals and their ability to displace other metals in aqueous solutions, which has implications in various fields such as metallurgy, corrosion prevention, and the extraction of metals.