In basic acid base chemistry, what is the reaction between an acid and a base called, in which a salt and water are usually formed?

Introduction / Context:
Acids and bases are central to many chemical reactions. When an acid and a base react together, they typically produce a salt and water. This fundamental process has a specific name that students encounter early in chemistry. The question asks for that name, reinforcing understanding of one of the most common reaction types in inorganic chemistry.

Given Data / Assumptions:

• Reactants: an acid and a base.
• Typical products: a salt and water.
• The reaction involves the combination of H+ ions from the acid and OH- ions from the base.
• We are dealing with standard aqueous acid base reactions.

Concept / Approach:
A reaction in which an acid reacts with a base to form salt and water is called a neutralisation reaction. In such reactions, the hydrogen ions from the acid and hydroxide ions from the base combine to form water, removing the acidic and basic characteristics. The remaining ions form the corresponding salt. This is distinct from processes like desalination, crystallisation, sublimation, or oxidation, which involve different physical or chemical changes.

Step-by-Step Solution:

Verification / Alternative check:
Textbooks on chemistry introduce neutralisation as the core concept when discussing reactions between acids and bases. The classic experiment of adding an acid to a base while monitoring pH demonstrates that the solution moves towards a neutral pH as the two react. Many real world processes, such as treating acid spills with lime or antacid tablets neutralising excess stomach acid, are described using the term neutralisation. These consistent usages confirm that the correct name for the reaction is neutralisation.

Why Other Options Are Wrong:

• Desalination: Refers to the process of removing salt from sea water to obtain fresh water, not to acid base reactions.
• Crystallisation: A physical process where dissolved substances form solid crystals, usually on cooling or evaporation.
• Sublimation: The direct conversion of a solid to a gas without passing through the liquid state, not related to acids and bases.
• Oxidation: Involves loss of electrons or gain of oxygen and is part of redox chemistry, not specifically the reaction of acids with bases.

Common Pitfalls:
Students may sometimes confuse neutralisation with more general terms like reaction or combination. Another error is to mix it up with desalination because both words involve removal of something from water. A helpful tip is to remember that neutralisation brings the pH towards 7, which is neutral, whereas desalination changes salt content but may not change pH significantly. Associating neutralisation with antacid tablets and common laboratory titrations can help lock in the correct concept.

Final Answer:
The reaction between an acid and a base that forms salt and water is called Neutralisation.