Reactivity Series of Metals: Chart, Features and Uses

Reactivity Series of Metals Overview

Metals are a group of elements that are widely used in various industries and in daily life. They are characterized by their high conductivity, ductility, and malleability. However, not all metals have the same reactivity. Some metals react with acids and water, while others do not. The reactivity series of metals is a list of metals arranged in the order of their decreasing reactivity. In this article, we will explain the reactivity series of metals and its importance in chemistry.

What is the Reactivity Series of Metals?

The reactivity series of metals is a list of metals arranged in the order of their decreasing reactivity. The most reactive metal is placed at the top of the list, and the least reactive metal is placed at the bottom. The reactivity series of metals is based on the ability of metals to displace other metals from their compounds. The more reactive a metal is, the more likely it is to displace another metal from its compound. The table below shows the metals along with their ions-

Why is the Reactivity Series of Metals Important?

The reactivity series of metals is important in chemistry because it helps predict the outcome of a reaction between a metal and a compound. For example, if a metal is more reactive than another metal in a compound, it will displace the less reactive metal from the compound. This knowledge is used in various industrial applications, such as the extraction of metals from their ores and in the production of alloys.

Salient Features of Reactivity Series of Metals

1. Metals present at the top of the reactivity series are highly electropositive metals. The electropositive character of metals decreases as we go down the series. 
2. The reducing power of metals decreases as we go down the series. Thus, potassium is the strongest reducing agent. 
3. As we go down the reactivity series, the ability of metals to remove hydrogen from hydrides decreases. 
4. Metals present in the reactivity series above hydrogen can remove hydrogen ions from dilute HCl or Dilute sulphuric acid. 
5. The metal which is more reactive than other metals can remove less reactive metal from its salt. Thus, metals placed at the top of the reactivity series can remove the metals that are present at the bottom of the series from their salts. 
6. The metals which are placed above in the series can be extracted by electrolysis. Metals from Zinc to Hg can be extracted by simply reducing their oxides, which is an inexpensive method.  
7. When we move down the series the electron-donating capacity of metals decreases.

Read more about the Electropositive Elements, Nitride, and Variable Valency.

Arrangement of the Reactivity Series of Metals

The following is the reactivity series of metals, arranged in order of their decreasing reactivity:

1. Potassium
2. Sodium
3. Calcium
4. Magnesium
5. Aluminium
6. Zinc
7. Iron
8. Tin
9. Lead
10. Copper
11. Silver
12. Gold
13. Platinum

The reactivity series of metals can be divided into two groups: highly reactive metals and less reactive metals. The highly reactive metals are at the top of the list, and the less reactive metals are at the bottom.

Highly Reactive Metals

The highly reactive metals are the metals that are most likely to react with water and acids. These metals include potassium, sodium, calcium, and magnesium.

1. Potassium - Potassium is the most reactive metal in the reactivity series. It reacts vigorously with water, producing hydrogen gas and a strong alkaline solution.
2. Sodium - Sodium is the second most reactive metal in the reactivity series. It also reacts vigorously with water, producing hydrogen gas and a strong alkaline solution.
3. Calcium - Calcium is less reactive than sodium and potassium but still reacts with water, producing hydrogen gas and a weak alkaline solution.
4. Magnesium - Magnesium is the fourth most reactive metal in the reactivity series. It reacts slowly with cold water and rapidly with hot water. It also reacts with dilute acids, producing hydrogen gas.

Less Reactive Metals

The less reactive metals are the metals that do not react with water or acids. These metals include zinc, iron, tin, lead, copper, silver, gold, and platinum.

1. Aluminum - Aluminium is less reactive than magnesium but more reactive than zinc. It reacts with dilute acids, producing hydrogen gas. However, it does not react with water.
2. Zinc - Zinc is less reactive than aluminum and but more reactive than iron. It reacts with dilute acids, producing hydrogen gas. However, it does not react with water.
3. Iron - Iron is less reactive than zinc but more reactive than tin. It reacts with dilute acids, producing hydrogen gas. However, it does not react with water.
4. Tin - Tin is less reactive than iron but more reactive than lead. It reacts with concentrated acids.

Factors Affecting Reactivity Series of Metals

The reactivity of metals is affected by several factors, including:

1. Electron configuration - Metals with fewer electrons in their outer shell are more reactive as they tend to lose them readily.
2. Electronegativity - The electronegativity of a metal determines how readily it can form positive ions. Metals with lower electronegativity are more reactive.
3. Atomic size - Smaller atoms tend to be more reactive as they have a greater nuclear charge and can lose electrons more readily.
4. Heat - Some metals become more reactive when heated, while others become less reactive.
5. Concentration - The reactivity of metals with acids is affected by the concentration of the acid. Dilute acids tend to react more slowly than concentrated acids.

The table below shows the various metal reactions with oxygen, water, and common acids:

Note: The table is not exhaustive and may not include all reactions of each metal with water, oxygen, and acids. It is intended as a general guide to the reactivity of metals with these substances.

Important uses of the Reactivity Series of Metal

In addition to shedding light on the properties and reactivity of metals, the reactivity series holds significant practical value. One of its key applications is in predicting the outcome of various reactions involving metals, such as those with water, acids, and single displacement reactions. By referring to the activity series, these reactions can be anticipated, and their products predicted.

Reaction Between Metals and Water

Metals that are more reactive than calcium, including calcium itself, can undergo a reaction with cold water to generate the corresponding hydroxide and release hydrogen gas. For instance, when potassium reacts with water, it produces potassium hydroxide and H2 gas, as indicated by the chemical equation below:

2K + 2H2O → 2KOH + H2

Thus, by consulting the reactivity series of metals, it becomes possible to anticipate and forecast the reactions that will occur between metals and water.

Reaction Between Metals and Acids

Metals that rank higher than lead on the activity series can form salts when they react with hydrochloric acid or sulfuric acid, accompanied by the release of hydrogen gas. One instance of such a reaction is the one that occurs between zinc and sulfuric acid, which generates zinc sulfate and H2 gas as products, as shown by the following chemical equation:

Zn + H2SO4 → ZnSO4 + H2

Therefore, by utilizing the reactivity series, it is possible to anticipate and forecast the reactions that will take place between certain metals and acids.

Single Displacement Reactions Between Metals

High-ranking metals on the reactivity series can readily reduce the ions of low-ranking metals. Consequently, low-ranking metals can be easily displaced by high-ranking metals in single displacement reactions between them. A notable example of such a reaction is the displacement of copper from copper sulfate by zinc, which can be represented by the chemical equation below:

Zn (s) + CuSO4 (aq) → ZnSO4 (aq) + Cu (s)

This principle has practical applications in the extraction of metals. For instance, titanium is obtained from titanium tetrachloride through a single displacement reaction with magnesium. Hence, the reactivity series of metals can be utilized to anticipate and forecast the outcome of single displacement reactions.

Reactivity Series of Metal: Things to Remember

1. The Reactivity Series is an arrangement of metals in order of their reactivity, with the most reactive metal placed at the top and the least reactive metal at the bottom.
2. The reactivity of a metal depends on its ability to lose electrons and form positive ions.
3. Metals higher up in the Reactivity Series can displace metals lower down in the series in single displacement reactions.
4. Metals higher up in the Reactivity Series can react with acids to produce hydrogen gas and a salt of the metal.
5. Metals lower down in the Reactivity Series do not react with water or acids.
6. The Reactivity Series can be used to predict the outcome of reactions between metals and water, acids, and single displacement reactions.
7. The Reactivity Series is important in the extraction of metals from their ores, as it determines the method used for extraction.
8. The Reactivity Series is a useful tool in chemistry for predicting and understanding the behavior of metals in various reactions.