How can we test for halide ions, Cl⁻ (aq) , Br⁻ (aq) and I⁻(aq).

If an unknown compound is dissolved in dilute nitric acide and silver nitrate solution is added, a precipitate will form if the unknown solutions contains halide ions. The precipitate will be silver chloride (AgCl), silver bromide (AgBr) or silver iodide (Agl)