Chemical properties of metals

Metals undergo characteristic chemical reactions, which distinguish them from non-metals. These include their reactivity with acids, water, and oxygen:

(a) Reactions with Dilute Acids:

• Some metals react with dilute acids to form a salt and hydrogen gas.

• Example:

  • Magnesium reacts with hydrochloric acid to form magnesium chloride and hydrogen:

Magnesium  +  Hydrochloric acid  →  Magnesium chloride  +  Hydrogen

Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)

(b) Reactions with Cold Water and Steam:

• Some metals react with cold water to form a metal hydroxide and hydrogen gas.

  • Example: Sodium reacts vigorously with cold water to form sodium hydroxide and hydrogen:
    
    

Sodium + Water → Sodium hydroxide + Hydrogen

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

• Some metals react with steam to produce a metal oxide and hydrogen gas.

  • Example: Iron reacts with the water in steam to form iron oxide and hydrogen.

Iron + Water → Iron oxide + Hydrogen 

3Fe(s) + 4H2O(g) → Fe3O4(s) + 4H2(g)

(c) Reactions with Oxygen:

• React with oxygen to form basic metal oxides.

  • Example: Magnesium burns in oxygen to form magnesium oxide:

Magnesium + Oxygen →  Magnesium oxide

2Mg(s) + O2(g) → 2MgO(s)