Reactivity of Metals : Water, Acids and Oxygen

Reactivity of Metals: Each metal reacts differently when it comes into contact with water, oxygen, and air. The reactivity of metals depends on the chemical composition and the conditions under which the reaction takes place. The ‘reactivity series’ of metals is a table containing the names of metals and their reactivity levels with the mentioned elements, in the descending order of their reactivity.

By looking at the reactivity series of metals, one can get a whole lot of information about whether or not a metal in the list can displace another and how easily. Let us learn more about the reactivity of metals in this article.

What is Reactivity Series of Metals?

The reactivity series of metals, sometimes called the activity series of metals, is the listing of metals in a tabular form in the descending order of their reactivity. This means, metals that are highly reactive appear at the top of the reactivity series followed by metals with lower reactivities. As alkali metals are the most reactive metals, you will find them at the top of the list. On the same note, as Platinum is the least reactive metal, it is seen at the bottom of the list.

Reactivity Series of Metals

It is not practical to list all the 90+ metals in the reactivity series. However, most of the commonly used metals are included in the list that is given below.

1. Potassium
2. Sodium
3. Lithium
4. Barium
5. Strontium
6. Calcium
7. Magnesium
8. Aluminium
9. Manganese
10. Zinc
11. Chromium
12. Iron
13. Cadmium
14. Cobalt
15. Nickal
16. Tin
17. Lead
18. Hydrogen
19. Antimony
20. Bismuth
21. Copper
22. Mercury
23. Silver
24. Gold
25. Platinum

What Can We Understand From Reactivity Series of Metals

Let’s find out.

1. Metals from 1-6 : Reacts with water
2. Metals from 6-16 : Reacts with acid
3. Hydrogen is included in the list for the sake of comparison
4. Metals from 18-25 : These are highly unreactive metals

Understanding the Chemical Properties of Metals

Here are some of the most important chemical properties of metals that could be inferred from the reactivity series.

• The metals at the top of the reactivity series like Potassium, Sodium and Lithium can get easily oxidised, which means they can corrode easily. 
• As we travel down the reactivity series, the corroding property reduces and so do their electropositivity
• Metals whose names are mentioned at the top of the table can displace those that are below their salt solutions
• It requires greater energy to isolate metals mentioned at the top of the list, from their ores and other compounds.
• Metals as we go down the reactivity series have less electron-donating ability.

Uses of Reactivity Series of Metals

It is true that the reactivity series gives us an insight into the chemical reactivity of the metals and a comparison between them. But there is also another important lesson that we can learn from the reactivity series, which is understanding the reaction between metals with atmospheric oxygen, water and acids.

Reaction of Metals with Atmospheric Oxygen

One of the salient characteristics of metals as we all already know, is that they lose electrons and form cations. When metals react with atmosphere oxygen they form metal oxides. But interestingly, not all the metals react with atmospheric oxygen at the same level. Some metals are highly reactive while there are others that show low reactivity. This is exactly what has been depicted in the reaction series. As you can see from the table, metals such as gold and platinum do not form oxides easily when exposed to air, which means they are unreactive. Therefore, they are listed at the bottom of the table.

Reaction of Metals With Acids

It is possible to predict the reaction of metals with acids by looking at the reactivity series and let us learn how.

In the reactivity series given above, Lead and the metals mentioned above lead form salts when they react with hydrochloric acid or sulphuric acid. Hydrogen gas is produced during reaction. Another example could be the reaction between zinc and sulphuric acid, in which  zinc sulphate and H2 gas are formed as products.

Reaction of Metals With Water

Refer to the reactivity series again. Calcium and other metals that appear above it in the reactivity series are highly reactive with cold water, forming corresponding hydroxide during the process. Also note that the reaction produces hydrogen gas. Similarly, the reaction between potassium and water produces potassium hydroxide and hydrogen gas.

Hope the information provided in this article is helpful to you in understanding the reactivity series of metals in a detailed manner. For more such articles, keep following Embibe.