ACTIVITY SERIES OF METALS : Predicting Reactivity - The activity series of metals is an empirical tool used to predict products in displacement reactions and reactivity of metals with water and acids in replacement reactions and ore extraction. It can be used to predict the products in similar reactions involving a different metal.

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Activity Series

Activity Series of Metals: Predicting Reactivity

by Todd Helmenstine

The activity series of metals is an empirical tool used to predict products in displacement reactions and reactivity of metals with water and acids in replacement reactions and ore extraction.

It can be used to predict the products in similar reactions involving a different metal.

Exploring the Activity Series Chart

The activity series is a chart of metals listed in order of declining relative reactivity.

The top metals are more reactive than the metals on the bottom.

For example, both magnesium and zinc can react with hydrogen ions to displace H₂ from a solution by the reactions:

Mg(s) + 2 H⁺(aq) → H₂(g) + Mg²⁺(aq)

Zn(s) + 2 H⁺(aq) → H₂(g) + Zn²⁺(aq)

Both metals react with the hydrogen ions, but magnesium metal can also displace zinc ions in solution by the reaction:

Mg(s) + Zn²⁺ → Zn(s) + Mg²⁺

This shows magnesium is more reactive than zinc and both metals are more reactive than hydrogen.

This third displacement reaction can be used for any metal that appears lower than itself on the table.

The further apart the two metals appear, the more vigorous the reaction.

Adding a metal like copper to zinc ions will not displace the zinc since copper appears lower than zinc on the table.

The first five elements are highly reactive metals that will react with cold water, hot water, and steam to form hydrogen gas and hydroxides.

The next four metals (magnesium through chromium) are active metals that will react with hot water or steam to form their oxides and hydrogen gas.

All the oxides of these two groups of metals will resist reduction by H₂ gas.

The six metals from iron to lead will replace hydrogen from hydrochloric, sulfuric and nitric acids.

Their oxides can be reduced by heating with hydrogen gas, carbon, and carbon monoxide.

All the metals from lithium to copper will combine readily with oxygen to form their oxides.

The last five metals are found free in nature with little oxides. Their oxides form through alternate pathways and will readily decompose with heat.

The series chart below works remarkably well for reactions that occur at or near room temperatures and in aqueous solutions.

Activity Series of Metals

Metal	Symbol	Reactivity
Lithium	Li	displaces H2 gas from water, steam and acids and forms hydroxides
Potassium	K
Strontium	Sr
Calcium	Ca
Sodium	Na
Magnesium	Mg	displaces H2 gas from steam and acids and forms hydroxides
Aluminum	Al
Zinc	Zn
Chromium	Cr
Iron	Fe	displaces H2 gas from acids only and forms hydroxides
Cadmium	Cd
Cobalt	Co
Nickel	Ni
Tin	Sn
Lead	Pb
Hydrogen gas	H2	included for comparison
Antimony	Sb	combines with O2 to form oxides and cannot displace H2
Arsenic	As
Bismuth	Bi
Copper	Cu
Mercury	Hg	found free in nature, oxides decompose with heating
Silver	Ag
Palladium	Pd
Platinum	Pt
Gold	Au

 

Todd Helmenstine Biography

Todd Helmenstine is a science writer, graphic artist, and IT professional.

Mr. Helmenstine has bachelor of art degrees in physics and mathematics from Hastings College in Hastings, Nebraska.

Todd is best known for his popular printable periodic tables and periodic table wallpapers. His work has been featured on About.com, ThoughtCo.com, and showcased here on Science Notes. The tables have appeared, by permission, in numerous textbooks, journals, and videos.

How Todd Helmenstine Makes Periodic Tables

Most of the printable periodic tables and other illustrations are made using Adobe Illustrator and Adobe Photo Shop. In some cases, 3-D renders are made, using Incendia or Bryce.

https://www.thoughtco.com/activity-series-of-metals-603960