Reactivity Series of Metals

What is it?

The Reactivity Series of Metals is an indication of how easily it reacts or how easily metal atoms ionize (from ions by loosing the valance electrons). The greater the ease of ionization the more rapidly it reacts with chemical reagents.

What was it created based on

1. How vigorously the metal reacts with water, steam, acid and oxygen.
2. How easily the metal compounds are decomposed when they are eaten.
3. Whether a metal can displace another metal from its compounds.

The reactivity series is arranged in a way where the most reactive metals are higher up on the reactivity series and the least reactive lower down. In other words the higher the metal the more reactive it is.

Metallic Reactivity series list

Metals with Oxygen

All metals react with oxygen to form ionic compounds known as metallic oxide:

1. Metals under reactivity series from Potassium to Calcium react spontaneously with oxygen in air.
2. Other metals such as magnesium & aluminum react more slowly and become covered with an oxide layer.
3. Zinc & Iron react even more slowly in dry air.
4. Copper can tarnish over many years therefore copper reacts very slowly.
5. The metals lower down on the Reactivity Series react even slower than copper in dry air.

N.B. the more spontaneous the reaction occurs under the same conditions, the more reactive the metal is.

• 4Al(s) + 3O2(g) → 2AlO(s) (Aluminum Oxide)
• 4Fe(s) + 3O2(g) → 2Fe2 O3(s) (Iron [III] Oxide [rust])
• 2Cu(s) + O2(g) → 2CuO(s) (Copper [II] Oxide)

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Metals with water

1. Metals such as sodium, potassium & calcium react with cold water to form metal hydroxide.
2. Magnesium & aluminum react with room temp. water and will react with cold water very slowly.
3. Zinc, iron & lead react with steam to form metal oxides. N.B. Aluminum may not always react with cold water but will always react with steam.
4. Copper and metals lower on the series does not react with water or steam.

• 2K(s) + H2O → 2KOH (ag) + H2(g)
• Ca(s) + 2H2O(1) → Ca(OH)2(aq) +H2(g)
• Fe(s) + H2O(g) → Fe2O3(s) + H2(g)
• Zn(s) + H2O(g) → ZnO(s) + H2(g)

Metals with with Dilute acids

The acids used here are dilute hydrochloric acid or dilute sulfuric acid. The product of this reaction is a salt & hydrogen gas.

1. Potassium reacts extremely violently.
2. Sodium, calcium, magnesium and aluminum reacts violently.
3. Zinc reacts fairly vigorously, in most reactions involving aluminum and magnesium they react vigorously similar to zinc.
4. Iron & lead react very slowly
5. Copper and the metals below do not react with dilute acids.

N.B. Hydrogen can be placed in the reactivity series of metals (although it doesn't always react as a metal would) between lead and copper.

• 2HCL(aq) + Co(s) → CoCL2(aq) + H2(g)
• H2SO4 (aq) + Pb(s) → PbSO4(aq) + H3(g)

Displacement Reactions

Patterns in reactivity of metals can be established by reacting a chosen metal with the solution of salt of other metals. The more reactive metals (metals higher on the reactivity series) will displace the less reactive metals from its compound/salt.

• Mg(s) + CuSO4(aq) → MgSO4(aq) + Cu(s)
• Ag(s0 + CaCL2(aq) → No reaction

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