Question

why an ionic solute dissolving in water is not a chemical reaction

Answer 1

We typically assume dissolution to be a PHYSICAL change, since it chage its phase

example, let it be NaCl , sodium chloride

from NaCl(s) solid crystal, with lattice network, will form aqueous solution:

NaCl(s) --> NaCl(aq)

note that this is pretty similar to:

Na(s) --> Na(l) which is melting,

it only changes phase,

important to note that in solvation,

water molecule will form poles and interact with its dipole with the salts cation:

NaCl(aQ) --> Na+ and Cl- ions in solution

Also:

NOTE that we could evaporate all water, and we will still get the same ionic soltue in solid form, meaning that it never reacted chemically.