Question

Dissolution of salt in water is ……………Change?

Answer 1

Hint: We have to remember that the physical change can be look while looking at the change in appearance for any chemical reaction that is taking place for example a color change whereas chemical change on the other hand involves the formation of new chemical species which result as a change in any chemical reaction, like endothermic or exothermic change.

Complete answer:
We must have to know that the salt which is chemically known as sodium chloride is completely soluble in water. The process for the dissolution of salt in water does not require any heat or no heat is evolved during this change thus the process is considered to be endothermic in nature. When sodium chloride is dissolved in water, it dissociates itself into sodium and chloride ions. The chemical equation can be represented as:
\[NaCl\left( s \right) \to N{a^ + }\left( {aq} \right) + C{l^ - }\left( {aq} \right)\]
The reactants in this chemical reaction are different from the products as a salt is dissociating into its respective cation and anion. Since sodium chloride is dissociating itself into its ions thus it is considered to be an ionic salt. The reaction so formed is endothermic as no heat is involved during this reaction.

Note:
We have to remember that a physical change on the other hand can be studied as the reaction in which no new chemical entity is formed its only a color change or physical state that is changing these changes are known as physical change for example when you dissolve sugar in water no new entity is formed its only solute and solvent reacting to produce solution.