Question

An oxide that combines with water to give an acid is termed:

Answer 1

Hint : Oxides are of many types, such as basic oxide, acidic oxide, neutral oxide and amphoteric oxides. Each type of oxide behaves in a distinguished way, but amphoteric oxide can exhibit both, acidic as well as basic nature.

Complete Step By Step Answer:
The oxide that combines with water to give and acid is termed as acidic oxides. These oxides on their reaction with water give their respective acids.
Acidic oxides are oxides of only on-metals from group 14 to 17, no other oxide works as an acidic oxide. Acidic oxides are also known as acidic anhydrides. When these acidic oxides combine with bases, they produce their respective salts.
This works in the same way as acids, they combine with base to give respective salt. Some examples of acidic oxides are sulphur dioxide, sulphur trioxide, carbon dioxide, etc.
The reaction of sulphur dioxide and carbon dioxide with water produces sulfurous acid and carbonic acid respectively. The reactions of formation of sulfurous and carbonic acids are given below.
$S{{O}_{2}}+{{H}_{2}}O\xrightarrow{{}}{{H}_{2}}S{{O}_{3}}$
The above reaction is the formation of sulfurous acid by the reaction of sulphur dioxide with water.
$C{{O}_{2}}+{{H}_{2}}O\xrightarrow{{}}{{H}_{2}}C{{O}_{3}}$
The above reaction is the formation of carbonic acid by the reaction of carbon dioxide with water.
Let us see how sulphur dioxide in reaction with a base, sodium hydroxide, produces salt.
$S{{O}_{2}}+2NaOH\xrightarrow{{}}N{{a}_{2}}S{{O}_{3}}+{{H}_{2}}O$
This proves that acidic oxides can also make salts when subjected to reaction with base.

Note :
Similar to acidic oxides, basic oxides on reaction with water make bases. Also, on reaction of basic oxides with acid give their respective salts. Amphoteric oxides can act as both, acidic as well as basic oxides. For example, $HS{{O}_{4}}^{-}$ ions on reaction with water can give both hydroxide and hydronium ions. Hydroxide ions are the significance of base and hydronium ions are the significance of acid.
The nature that they show depends on the other reactant. On the contrary, neutral oxides do not show any kind of acidic or basic nature, but they are useful in displacement reactions.