**Hydrolysis Reaction**

Hydrolysis is a chemical reaction in which water is used to break down a compound into its constituent parts. It involves the splitting of a chemical bond in a molecule by the addition of a water molecule. Hydrolysis reactions are commonly observed in biological systems, industrial processes, and laboratory experiments.

Among the three examples provided, the hydrolysis reaction can be identified as follows:

**1) NH4Cl → NH4 + Cl**
This reaction does not involve the addition of water molecules. Instead, it represents the dissociation of ammonium chloride into its constituent ions, ammonium (NH4+) and chloride (Cl-). This process is known as ionization or dissociation, not hydrolysis.

**2) NH4 + H2O → NH4OH + H**
In this case, the reaction represents the hydrolysis of ammonium (NH4+) with water (H2O) to form ammonium hydroxide (NH4OH) and a hydrogen ion (H+). Hydrolysis occurs when a water molecule donates a hydroxyl group (OH-) to the ammonium ion, resulting in the formation of ammonium hydroxide. Therefore, this reaction can be considered an example of hydrolysis.

**3) Na + H2O → NaOH + H**
This reaction does not involve the addition of water molecules or the breaking of any chemical bonds. It represents the dissociation of sodium metal (Na) into sodium hydroxide (NaOH) and a hydrogen atom (H). Similar to the first example, this process is not a hydrolysis reaction but rather a simple dissociation.

**In summary, the second example (NH4 + H2O → NH4OH + H) is the only one that represents a hydrolysis reaction.** It involves the breaking of a chemical bond between the ammonium ion and water, leading to the formation of ammonium hydroxide and a hydrogen ion. The other two examples, although involving the formation of new compounds, do not meet the criteria for hydrolysis reactions.

Basically, hydrolysis reaction hota hai...kisi v given chiz ki water ke sath reaction..ok..
So, here option 1 is incorrect..
Now at option 2 :-- NH4 + H2O ---> NH4OH + H+
And at option 3 :-- Na+ + H20 ----> NaOH + H+
on comparing option 2 and 3
So, option 3 is not possible because Na+(reduction potential ) < h+="" means="" h+="" ka="" salt="" wo="" hamesha="" na+="" se="" pahle="" banega="" or="" na+="" ionic="" form="" me="" rahna="" prefer="" karta="" hai...so,="" na+="" water="" me="" as="" ion="" hi="" rahega..so,="" option="" is="" not="" feasible="" and="" not="" />
And, option 2 is feasible and possible...

So, correct option is (2)...

$$Hope it's help... $$