`AgCl` is less soluble in `AgNO_(3)` solution than in pure water. Explain.

Explanation

The ionisation equuilibrium of `AgCl` can be written as
`AgCl(s)harrAg^(+)(aq)+Cl^(-)(aq)`
in the saturated solution ionic product `[Ag^(+)][Cl^(-1)]` is equal to the solubility product ksp of `AgCl`.
Similarly the ionisation equilibrium of `AgNO_(3)` can be written as
`AgNO_(3)hArrAg^(+)+NO_(3)^(-)`
By the addition of `AgNO_(3)` to `AgCl` the number of `Ag^(+)` increases and the ionic product `[Ag^(+)][Cl^(-)]` exceeds the solubility product of `AgCl`. So precipitation occurs causing the decreases in solubility of `AgCl`.