Non-Metallic Oxides: An Introduction
All non-metals combine with oxygen to generate covalent oxides, which then react with water to create acids or use bases to create salts. Most non-metal oxides are acidic in nature, and when they combine to create oxy acids, they produce hydronium ions (H3O+) in an aqueous medium. The actions of acidic oxides can be categorised in two broad terms. Initially, oxides where the non-metal displays one of its typical oxidation values, such as sulphur trioxide (SO3) as well as dinitrogen pentoxide (N2O5), are referred to as acid anhydrides.
Base has a harsh flavour and a soapy texture to it. A base tends to turn red litmus paper into blue. Bases include components such as potassium hydroxide (caustic potash), sodium hydroxide (caustic soda), sodium carbonate (washing soda), calcium hydroxide, lime (calcium oxide), and so on. Non-metallic oxides do not dissolve in water, while in a basic aqueous solution, it readily dissolves to generate salt.
Reaction of Non-Metallic Oxide with Base
Non-metal oxides are naturally acidic. Carbon dioxide, for instance, is a non-metal oxide. Carbonic acid is formed whenever carbon dioxide is dissolved in water.
Hence, whenever a reaction of non-metallic oxide with base occurs, both reactants neutralise one another, producing salt and water as a by-product.
The general equation of the reaction of non-metallic oxide with base is:
\[Non - Metallic~Oxide + Base \to Salt + Water\]
Reaction of Non-Metallic Oxide with Base Examples
The reaction of non-metallic oxide with base examples is explained using certain chemical equations below.
With Sodium Hydroxide (NaOH) Base
The non-metallic oxide carbon dioxide (CO2) reacts with base sodium hydroxide (NaOH), and as a result, a salt sodium carbonate (Na2CO3) and water is produced.
\[2NaOH\left( {aq} \right) + C{O_2}\left( g \right) \to N{a_2}C{O_3}\left( {aq} \right) + {H_2}O\left( l \right)\]
This process demonstrates that non-metal oxides like carbon dioxide (CO2) are acidic.
With Calcium Hydroxide Ca(OH)2 Base
The non-metallic oxide carbon dioxide (CO2) reacts with base calcium hydroxide Ca(OH)2 and as a result, salt calcium carbonate (CaCO3) and water are produced.
\[Ca{\left( {OH} \right)_2}\left( {aq} \right) + C{O_2}\left( g \right) \to CaC{O_3}\left( {aq} \right) + {H_2}O\left( l \right)\]
This process demonstrates that non-metal oxides like carbon dioxide (CO2) are acidic.
With Magnesium Hydroxide Mg(OH)2 Base
The non-metallic oxide carbon dioxide (CO2) reacts with base magnesium hydroxide Mg(OH)2 and as a result salt magnesium carbonate (MgCO3) and water is produced.
\[Mg{\left( {OH} \right)_2}\left( {aq} \right) + C{O_2}\left( g \right) \to MgC{O_3}\left( {aq} \right) + {H_2}O\left( l \right)\]
This process demonstrates that non-metal oxides like carbon dioxide (CO2) are acidic.
With Potassium Hydroxide (KOH) Base
The non-metallic oxide sulphur dioxide (SO2) reacts with base potassium hydroxide (KOH) and as a result, salt potassium sulphate (K2SO3) and water is produced.
\[2KOH\left( {aq} \right) + S{O_2}\left( g \right) \to {K_2}S{O_3}\left( {aq} \right) + {H_2}O\left( l \right)\]
This process demonstrates that non-metal oxides like sulphur dioxide (SO2) are acidic.
Characteristics of Non-Metallic Oxides of Sulphur and Nitrogen in Atmosphere
Oxides in the atmosphere have the potential to interact with water to produce acid rain. Water reacts with non-metal oxides like sulphur dioxide (SO2) and nitrogen oxide (NO2). These oxides can break down in the water to create acid, which then rains down as acid rain on the land. Consequently, this acid rain leads to damage to buildings and rocks and hazards to wildlife. Sulphur can easily react with atmospheric air to form sulphur dioxide.
Interesting Facts
The p-block is dominated by non-metals. They produce a wide range of oxide compounds.
Acidic oxides are generally referred to as non-metallic oxides.
When non-metallic oxides and water interact, acids are produced. Non-metallic oxides are acidic, and when SO3 is combined with water, for example, the resulting mixture of H2SO4 is extremely acidic.
Metallic oxides with base possess very low melting and boiling point, and even while molten, they do not conduct electricity.
Sulphur and phosphorus are highly soluble in water and form acidic oxides and so they are neutralized with base to form salts.
Key Features
Non-metallic oxides react with base to produce corresponding salt and water proving that non-metallic oxides are acidic in nature.
The general equation of reaction of non-metallic oxides with base denotes Non-metallic oxide + base = salt + water.
Bases which can react with non-metallic acids are potassium hydroxide (caustic potash), sodium carbonate (washing soda), lime (calcium oxide), sodium hydroxide (caustic soda), calcium hydroxide, and so on.
Non-metallic oxides are covalent compounds because they exchange particles with oxygen atoms to create oxide molecules.
FAQs on Reaction of Non-Metallic Oxide with Base
1. What types of base reacts with non-metal oxides?
Bases come in two types; they are water soluble and water insoluble. The non-metal oxides can react with both.
2. Why are non-metal oxides called as acidic oxides?
The non metallic oxides react with water to produce acid and makes the aqueous solution acidic by increasing the hydrogen ion concentration in the solution. Therefore, non-metal oxides are called acidic oxides. Common example is acidic rain which is formed due to the reaction of rain water and sulphur and nitrogen oxides.
3. Mention some of the non-metallic oxides other than carbon dioxide?
Sulphur dioxide (SO2), nitrogen dioxide (NO2), dichlorine monoxide (Cl2O), xenon tetroxide (XeO4) and so on.
