Reactivity Series

What is the Reactivity Series?

The reactivity series of metals, also known as the activity series, refers to the arrangement of metals in the descending order of their reactivities.

The data provided by the reactivity series can be used to predict whether a metal can displace another in a single displacement reaction. It can also be used to obtain information on the reactivity of metals towards water and acids.

A chart of the reactivity series of common metals is provided below.

Reactivity Series of Metals

Metals tend to readily lose electrons and form cations. Most of them react with atmospheric oxygen to form metal oxides. However, different metals have different reactivities towards oxygen (unreactive metals such as gold and platinum do not readily form oxides when exposed to air).

Salient Features

  • The metals at the top of the reactivity series are powerful reducing agents since they are easily oxidized. These metals tarnish/corrode very easily.
  • The reducing ability of the metals grows weaker while traversing down the series.
  • The electro positivity of the elements also reduces while moving down the reactivity series of metals.
  • All metals that are found above hydrogen in the activity series liberate H2 gas upon reacting with dilute HCl or dilute H2SO4.
  • Metals that are placed higher on the reactivity series have the ability to displace metals that are placed lower from their salt solutions.
  • Higher ranking metals require greater amounts of energy for their isolation from ores and other compounds.

Another important feature of the activity series is that while travelling down the series, the electron-donating ability of the metals reduces.

Long Tabular Form of the Reactivity Series

The reactivities of metals are tabulated below (in the descending order) along with their corresponding ions. Note that the metals in Red react with cold water, those in Orange cannot react with cold water but can react with acids, and those in Blue only react with some strong oxidizing acids.

Reactivity Series of Metals Ions Formed
Caesium Cs+
Francium Fr+
Rubidium Rb+
Potassium K+
Sodium Na+
Lithium Li+
Barium Ba2+
Radium Ra2+
Strontium Sr2+
Calcium Ca2+
Magnesium Mg2+
Beryllium Be2+
Aluminium Al3+
Titanium Ti4+
Manganese Mn2+
Zinc Zn2+
Chromium Cr3+
Iron Fe3+
Cadmium Cd2+
Cobalt Co2+
Nickel Ni2+
Tin Sn2+
Lead Pb2+
Hydrogen H+ (Non-Metal, Reference for Comparison)
Antimony Sb3+
Bismuth Bi3+
Copper Cu2+
Tungsten W3+
Mercury Hg2+
Silver Ag+
Platinum Pt4+
Gold Au3+

Despite being a non-metal, hydrogen is often included in the reactivity series since it helps compare the reactivities of the metals. The metals placed above hydrogen in the series can displace it from acids such as HCl and H2SO4 (since they are more reactive).

Important uses of Reactivity Series

Apart from providing insight into the properties and reactivities of the metals, the reactivity series has several other important applications. For example, the outcome of the reactions between metals and water, metals and acids, and single displacement reactions between metals can be predicted with the help of the activity series.

Reaction Between Metals and Water

Calcium and the metals that are more reactive than calcium in the reactivity series can react with cold water to form the corresponding hydroxide while liberating hydrogen gas. For example, the reaction between potassium and water yields potassium hydroxide and H2 gas, as described by the chemical equation provided below.

2K + 2H2O → 2KOH + H2

Therefore, the reactivity series of metals can be used to predict the reactions between metals and water.

Reaction Between Metals and Acids

Lead and the metals ranking above lead on the activity series form salts when reacted with hydrochloric acid or sulphuric acid. These reactions also involve the liberation of hydrogen gas. The reaction between zinc and sulphuric acid is an example of such a reaction. Here, zinc sulfate and H2 gas are formed as products. The chemical equation is:

Zn + H2SO4 → ZnSO4 + H2

Thus, the reactions between metals and some acids can be predicted with the help of the reactivity series.

Single Displacement Reactions Between Metals

The ions of low ranking metals are readily reduced by high ranking metals on the reactivity series. Therefore, low ranking metals are easily displaced by high ranking metals in the single displacement reactions between them.

A great example of such a reaction is the displacement of copper from copper sulfate by zinc. The chemical equation for this reaction is given by:

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

This concept has several practical applications in the extraction of metals. For example, titanium is extracted from titanium tetrachloride via a single displacement reaction with magnesium. Thus, the reactivity series of metals can also be used to predict the outcome of single displacement reactions.

Frequently Asked Questions

What does a reactivity series show?

In order of reactivity the reactivity series shows metals. A metal’s reactivity can be worked out by studying its reactions in both the reactions to competition and displacement.

What metal is the least reactive?

The elements in the periodic table known as the transition metals are much less reactive, and metals such as gold and platinum endorse the bottom of the list, exhibiting less in the way of chemical reaction with any ordinary reagents.

What is metal reactivity?

The metal reactivity sequence, also known as the set of operations, refers to the organization of metals in the ascending order of their reactivities. … Metals tend to lose electrons and form cations quickly. Some lead to the forming of metal oxides with ambient oxygen.

Which is the most reactive element?

The most reactive elementary group is alkali metals (situated far apart from intermediate metals and noble gases). Cesium is second from the bottom of this group, has 6 shells of electrons, and it matches the features of a reactive atom, making it the most reactive element.

Are non-metals Reactive or non-reactive?

Non-metal properties have a relatively low boiling point, and other non-metals are gases. Likewise, non-metals are poor heat conductors, and solid non-metals are dull and brittle. Many non-metals are strongly reactive, while others are in no way reactive. It depends on the number of electrons in the outer amount of energy.

To learn more about this concept and other related concepts, such as the electrochemical series, register with BYJU’S and download the mobile application on your smartphone.

10 Comments

  1. it was very useful thank you

  2. Thank you . It was very imformative.

  3. it was helpfull

  4. good article

  5. Hemant Pratap Singh

    Thank You. It was very helpful

  6. its really useful thank u

  7. Thank you it gave me a numerous knowledge about it. Thank you very much. From Tshering Lhamo( Bhutan)

  8. Very helpful information

  9. Good information

Leave a Comment

Your email address will not be published. Required fields are marked *

BOOK

Free Class