Reaction of silver ion and iodide ion

Question

When silver ion reacts with iodide ion, silver iodide is formed.

However, silver ion is an oxidising agent, while iodide ion is a reducing agent.

How come this is not a redox reaction?

(If it were a redox, the product would be silver and iodine.)

Answer 1

Consider the redox reaction between silver ion and iodide ion :
2Ag+(aq) + 2I-(aq) → 2Ag(s) + I2(aq)
Standard e.m.f. of the redox reaction is +0.26 V, and the reaction is feasible.

However, the activation energy of the redox reaction is much higher than that of the precipitation. Therefore, precipitate occurs instead of redox.
Precipitation : Ag+(aq) + Cl-(aq) → AgCl(s)