Question

explain the nature of the covalent bond formation of NH3CL

Answer 1

There is actually a coordinate bond (which is actually a kind of covalent bond in which only one of the participating atoms donate both of their electrons to form a covalent bond) between lone pair of nitrogen in ammonia(NH3) and a proton(H+ ion),which hence creates an ammonium ion(NH4+).

Further this ammonium ion due to a positive charge forms an ionic bond with chloride ion(Cl–).

So actually there are:-

three pure covalent bonds in NH3.

a coordinate bond(which is also a covalent bond) between NH3 (ammonia)and H+ ion(proton).

And of course an ionic bond between NH4+ (ammonium ion) and Cl–(chloride ion)

hope it helps u