Question

When $NaCl$ is dissolved in water, the sodium ion is:
A.Oxidised
B.Reduced
C.Hydrolysed
D.hydrated

Answer 1

Oxidising reagent: These are those molecules which gain one or more electrons. For example: hydrogen, oxygen and chlorine. The molecule's oxidising agent will act as reduced substance.
Reducing agent: These are those molecules which lose one or more electrons. For example: lithium aluminium hydride. The molecule's reducing agent will act as an oxidised substance.

Complete step by step solution:
Let us first read about oxidised, reduced, hydrolysed and hydrated molecules.
Oxidised: The substance which takes oxygen or loses hydrogen during the reaction, is known as oxidised. Or we can say that the molecule or atom which loses one or more electrons, is known as an oxidised molecule.
Reduced: The substance which loses oxygen or takes hydrogen during the reaction, is known as reduced molecule. Or we can say that the molecule or atom which gains one or more electrons, is known as reduced molecule.
Oxidising reagent: These are those molecules which gain one or more electrons. For example: hydrogen, oxygen and chlorine. The molecule's oxidising agent will act as reduced substance.
Reducing agent: These are those molecules which lose one or more electrons. For example: lithium aluminium hydride. The molecule's reducing agent will act as an oxidised substance.
Hydrolysed: When water molecule ruptures from the molecule, then the remaining compound is known as hydrolysed molecule.
Hydrated: When a compound has water molecules or molecules in its formula, then the compound is known as a hydrated molecule.
When $NaCl$ is dissolved in water then the sodium and chlorine ions dissociate. Sodium chloride is an ionic compound so when it reacts with water it dissociates into the ions. The reaction is as:
$NaCl + {H_2}O \to N{a^ + } + C{l^ - }$. And sodium and chlorine ions are surrounded by multiple molecules of water. This process is also known as hydration of sodium ion because in this process hydration of sodium ion takes place. Hence when $NaCl$ is dissolved in water, the sodium ion is hydrated.

So option D is correct.

Note: Ionic compound: The compounds which are formed by gain or loss of electrons, are known as ionic compounds. The elements which are more electronegative will lose electrons and the elements which are less electronegative will accept electrons.