Chemical Properties of Metals

A chemical property is an observable characteristic of a substance in a chemical reaction. A chemical reaction is the transformation of one substance into another. As the characteristics of the substances change during this process, chemical properties are observed.

Physical properties of metal

• Metals are normally solids at room temperature. At this temperature, the only metals that exist in liquid form are mercury and gallium.
• Metals have a gleaming aspect. Metallic luster refers to the characteristic sheen of metals. Glossy metals include gold, silver, platinum, aluminum, iron, zinc, and tin. In fact, gold, silver, and platinum are utilised to produce jewelry and decorative things because of this feature. 
• Hardness: Except for sodium and potassium, which seem to be soft and can be cut with a knife, most metals are hard and powerful. Metals such as iron, copper, and tin are examples of hard metals.
• Sonority: Metal is sonorous, this means that when struck, they generate a ringing sound.
• Metals can be pounded into thin sheets due to their malleability. This is referred to as malleability. When pounded with a hammer, an iron nail or wires made of copper, aluminium, silver, or gold would flatten into thin sheets.
• Melting and boiling points: The majority of metals have high melting and boiling points.

Chemical properties of metal

Metals and Oxygen Reaction

When metals react with oxygen, they produce metal oxides.

Metal Oxide  →  Metal + Oxygen

The intensity of a metal-oxygen reaction is determined by the metal’s chemical reactivity. Some metals react with oxygen even at ambient temperature, whereas others respond when heated, and yet others react when strongly heated.

The following are some examples:

Sodium Reaction with Oxygen: At normal temperature, sodium metal interacts with oxygen to generate sodium oxide.

     4Na   +    O2    →     2Na2O 

Potassium Metal Reaction with Oxygen: At ambient temperature, potassium metal reacts with oxygen to generate potassium oxide.

     4K   +    O2     →     2K2O 

Because potassium and sodium metals are highly reactive and react with oxygen at room temperature, they are stored in kerosene oil to prevent this reaction.

Metal Reactions with Water

When metals react with water, metal hydroxides and hydrogen gas are generated.

Metal + Water    →     Metal hydroxide + Hydrogen

However, not all metals react with water. The degree of a metal’s reaction with water is determined by its chemical reactivity. Some metals react with cold water, some with hot water, yet others with steam, and still others do not react with steam at all.

The following are some examples:

Aluminium’s reaction with water is as follows: When aluminium metal reacts with steam, it produces aluminium oxide and hydrogen gas.

     2Al   +     3H2O    →     Al2O3           +          3H2

Under normal conditions, aluminium metal does not react with water due to a thin but resistant layer of aluminium oxide on its surface.

Iron’s reaction with water: When iron reacts with steam, it produces iron oxide and hydrogen gas. Rust is formed when iron combines with moisture in the air (iron oxide).

3Fe          +       4H2O     →     Fe3O4            +        4H2

Other metals, on either hand, either do not react with water at all or do so very slowly. Lead, copper, silver, or gold do not react with steam.

Metal Reactions with Dilute Acids

When a metal combines with dilute acid, metal salt and hydrogen gas are generated.

 Metal + Dilute Acid    →     Metal Salt  +  Hydrogen       

All metals, however, do not react with dilute acids. The degree of a metal’s reaction with dilute acids is determined by its chemical reactivity. Some metals react explosively or incredibly quickly, whereas others respond slowly. Some metals react to heating, while others do not.

Magnesium Metal Reaction with Dilute Hydrochloric Acid: Magnesium metal reacts quickly with diluted hydrochloric acid to generate magnesium chloride and hydrogen gas.

Mg                +           2HCl     →      MgCl2           +         H2

When zinc metal combines with dilute sulfuric acid, it produces zinc sulphate and hydrogen gas. This procedure is used in the laboratory to generate hydrogen gas.

Zn          +       H2SO4    →     ZnSO4         +      H2

Metals react with solutions of other metal salts.

When metals react with such a solution of another metal salt, a displacement reaction occurs. In this reaction, the more reactive metal displaces the less reactive metal from its salt.

Metal A   +  Salt of metal B    →     Salt of Metal A  +   Metal B

The following are some examples:

Iron Displaces Copper from Copper Sulphate Solution: Iron replaces copper from copper sulphate solution.

Fe             +         CuSO4    →     FeSO4          +      Cu

Conclusion

Metals are known to be hard, ductile, malleable, good conductors of heat and electricity, and lustrous. Some metals, on the other hand, appear dull due to formation of an oxide layer on their surface. Metals and nonmetals have a variety of chemical properties. Metals’ chemical properties differ from nonmetals’ chemical properties. The capacity of the reaction with oxygen is determined by the metal’s chemical reactivity. Metals displace hydrogen from water and dilute acids, which is one of their chemical properties.