when an acid is allowed to react with a base to form salt and water. this chemical reaction is named as:

Correct option is D

Sol: The correct answer is (d) neutralisation reaction

Key Points:

When an acid reacts with a base, they form salt and water. This reaction is called a neutralisation reaction because the acid and base neutralize each other's properties.

​Example:

Hydrochloric acid + Sodium hydroxide:   HCl (acid) + NaOH (base) → NaCl (salt)+$$H_2O$$​ (water)

Sulfuric acid + Potassium hydroxide:  $$H _2​ SO _4​ +2KOH→K _2​ SO _4​ +2H _2​ O$$

​​Substances like litmus, phenolphthalein, or methyl orange are used to detect neutralisation by a color change.​

All other option:

• Combination Reaction: A reaction where two or more substances combine to form a single product.
• Acid-Base Reaction: A general term for reactions involving acids and bases, but specifically producing salt and water is termed neutralisation.
• ​Redox Reaction: A reaction involving the transfer of electrons between two species, encompassing reduction and oxidation processes.​